Search Results

L Lamellar Ichthyosis Define : rare, inherited skin disorder characterized by the abnormal formation and shedding of skin cells, leading to thick, scale-like patches on the skin's surface Appearance : born with a tight, shiny, and waxy collodion membrane, which peels off within the first few weeks, revealing large, dark, plate-like scales on the skin (fish-like scales) Locations : legs + skin folds (neck + armpits) Langerhans Cell Histiocytosis Histo : lots of edema, eos (Reniform, kidney bean shaped grooved nuclei) Stains : S100+, CD1a+, Langerin+ (forms birbeck granules) Linear IgA Bullous Dermatitis (LABD) Tx : Dapsone Lentigo Etiology : sun exposure and aging Description : Irregular-shaped tan or brown patches on the skin, usually with well-defined edges; surface can be either smooth or rough Lentigo Maligna Define : type of melanoma in situ characterized by slow-growing, flat, discolored patches of skin Location : face, neck, and arms Appearance : irregular patches that can be brown, dark brown, pink, red, white, or blue At risk : 70+ yo Tx : MOHs Lentigo Simplex Appearance : flat, brown or black spots Tx : cryotherapy, lasers, chemical peels, and topical retinoids and hydroquinone Leprosy / Hansen Disease Etiology : Mycobacterium leprae complex Types/Appearance: Paucibacillary/Tuberculoid Hansen disease = < 5 lesions = hypo or hyperpigmented macules with loss of sensation Multibacillary/Lepromatous Hansen disease = 6+ lesions = diffuse, symmetrical, infiltrative skin papules + plaques with dermal thickening; not always loss of sensation At risk : immigrants, exposure to armadillos Tx : PB = dapsone + rifampin for 12 mo; MB = dapsone + rifampin + clofazimine for 24 mo Leser-Trélat sign Description : explosive onset of multiple seborrheic keratoses (pigmented skin lesions), often with an inflammatory base Associated with : gastric adenocarcinoma Letterer-Siwe Disease Etiology : unknown cause, but the number of Langerhans cells in the skin and other organs are triggered to increase (type of Langerhans cell histiocytosis); BRAF V600E mutation associated Description : small pinkish papules or blisters that may be crusted or infected (appears like seborrheic dermatitis) At risk : <2 yo Location : scalp, neck, armpits, groin, and trunk Leukocytoclastic Vasculitis / hypersensitivity vasculitis / hypersensitivity angiitis Etiology : allergic reaction to drugs, Streptococcal URTI, infection from HBV, HCV, S. aureus, mycobacterium , and autoimmune disorders (RA, SS, SLE, HSP) Description : grouped rash on legs that include pustules, nodules, and mottling Leukonychia Etiology : trauma, chemotherapy, arsenic poisoning, hypoalbuminemia (Muehrcke lines), systemic disease (Terry nails) Description : partial or full opacification of the nail plate Lichen Planus Description : pruritic, purple, polygonal planar papules and plaques Locations : typically, wrists and ankles Associated with : HCV Lichen Sclerosus Etiology : progressive inflammatory disease Description : parchment-like atrophic area that is thinner and more white Associated with : SCC Lichen Simplex Chronicus / Neurodermatitis Etiology : hyperplasia of vulvar squamous epithelium Description : leathery, thick vulvar skin that is itchy Lichen Spinulosus Etiology: Lichenoid keratosis (BLK) Appearance : single, small, pink or reddish papule or plaque; can appear as a wart-like growth or a scaly, dry patch; shiny at first, take an alcohol wipe, will be dull appearance afterwards Vs . BCC will still be shiny afterwards Locations: trunk and upper extremities Tx : cryo, EDC Cause : unknown cause, but triggers include minor trauma such as friction, drugs, dermatitis, and sun exposure Description : single small gray-brown or inflamed plaque or papule Location : chest + upper extremities Lichtenberg Figures Etiology : Lightning strike injury Description : transient pink-red fractal pattern marks on the skin Lipodermatosclerosis bottle necking Lipomas painless Vs . angiolipomas are painful Livedo Reticularis Etiology : many causes, including cold exposure and chronic medical conditions (SLE, Cold AIHA, etc.) Description : bluish-red, lace-like pattern Localized Scleroderma (morphea) Etiology : unknown Description : 1. active stage = inflammatory erythematous plaque 2. sclerosis stage = yellow-ivory lesion 3. atrophy = cigarette-like paper Associated with : other autoimmune conditions Lupus Miliaris Disseminated Faciei Histo : small pea like palisading granuloma with central casseous necrosis Lupus pernio Etiology : Sarcoidosis Description : blue red to violet smooth shiny nodules + plaques Location : head + neck, especially nose, ears, lips, cheeks At risk : African American females Lyme Disease / Erythema Migrans Etiology : Borrelia burgdorferi (via Ixodes deer tick) Description : bull’s eye configuration that typicaly appears 7–14 days (range 3–33 days) after the infected tick bite At risk : living in the northeast Lymphangioma circumscriptum Description : small, firm, translucent vesicles Location : axillary folds, shoulders, neck, proximal limbs + buccal mucosa Lymphangitis Etiology : acute streptococcal infection of the skin Description : Tender red streaks often radiate from the wound toward the nearest lymph glands Lymphogranuloma venereum Etiology : C. trachomatis (L1-L3) Description : infection of lymphatics presenting with painless genital ulcers and painful inguinal lymphadenopathy Associated with : penile SCC A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

K Kaposi Sarcoma Etiology : HHV-8 Types : Classic : often affects middle aged men of Mediterranean or Eastern European descent Endemic : occurs in sub-Saharan Africans Iatrogenic : due to immunosuppressive drugs (esp. kidney transplants) AIDS-associated : most common Appearance : red, purple, or brown patches or nodules Location : lower extremities (esp. classic type), when disseminates it spreads to mouth, lungs, liver, other organs Kawasaki Disease Etiology : Medium-vessel vasculitis Description : polymorphous / morbilliform (measles like) / targetoid skin lesions -> desquamating rash (peeling of extremities) Location : trunk and extremities Keloid Etiology : dysregulation of the normal healing process resulting in excessive production of collagen, elastin, proteoglycans, and extracellular matrix proteins Description : Purplish-red, firm, smooth, and raised; can occur years after injury and grows beyond the initiating wound area Go to link Go to link Go to link Go to link Go to link Go to link Go to link Go to link Go to link 1/2 Keratoacanthoma (KA) Etiology : form of SCC (UV exposure) Appearance : flesh-colored or pink dome-shaped nodule with central keratin plug Location : face, neck, dorsal of upper extremities Tx : excision Keratoderma Blennorrhagica Associated with : reactive arthritis (Chlamydia) Description : painless desquamative psoriatic-like papulosquamous eruption Location : commonly found on the palms + soles but may spread to the scrotum, scalp, + trunk To play, press and hold the enter key. To stop, release the enter key. Keratoelastoidosis Marginalis Etiology: 1/4 Keratosis Pilaris (KP) Etiology : abnormal keratinization of the upper portion lining of the hair follicle Description : ‘goosebump’ or ‘chicken skin’ appearance Location : most common on posterior arms Go to link Go to link Go to link Go to link Go to link Go to link Go to link Go to link Go to link 1/2 Keratosis spinulosa Etiology: 1/6 Kindler Syndrome Etiology: AR mutation of KIND-I Go to link Go to link Go to link Go to link Go to link Go to link Go to link Go to link Go to link 1/1 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

O Onchocerciasis Etiology : Onchocerca volvulus (worm transmitted through bite of female blackfly) Description : initially painless skin nodules that progressively become very itchy due to dead larvae; chronic itching leads to permanent skin color changes (leopard skin) At risk : sub-Saharan Africa Ass. sx : irreversible blindness (photophobia, eye itching, pain), epilepsy Tx : oral ivermectin (1 does q3 mo to kill adult and larvae) +/- doxy Onycholysis Etiology : idiopathic or secondary to trauma, skin disease, nail infections, tumors, or systemic event Description : well-defined area of white opaque nail Associated with : Psoriasis, Lichen Planus, Onychomycosis, Eczema At risk : adult women Tx : clip affected portion, keep nail short, minimize trauma, avoid irritants, antimicrobial soaks to prevent secondary infection Onychomycosis Etiology : dermatophytes (75+% of cases), non-dermatophytes (aspergillum, candida, etc.) At risk : 65+ yo, diabetic, immunocompromised, athletes Location : MC at 1st toe Tx : Mild = 50/50 soak in vinegar/water 3x/wk; topical nail polish thing Severe = oral terbinafine/griseofulvin Go to link Go to link Go to link Go to link Go to link Go to link Go to link Go to link 1/2 Osler nodes Etiology : S. aureus (mostly), S. viridans (anything that can increase IC deposition) Description : raised, violaceous lesions Sx : "Osler nodes are Ouchy" = painful Location : finger + toe pads Tx : abx if underlying bacterial endocarditis, cutaneous lesions will resolve on own 1/4 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

J Janeway lesions Etiology : S. aureus (mostly), S. viridans (anything that can increase IC deposition) Description : painless, flat erythematous macules Locations : palms and soles Prog : spontaneously heal without scarring Tx : abx if bacterial endocarditis Jaundice Etiology : high levels of bilirubin (numerous causes) Description : yellowing of tissues Juvenile Spring Eruption Define : type of PMLE At risk : boys + young adult men during early spring Appearance : small, red, and sometimes itchy papules and vesicles 8-24 hours after exposure to sunlight, especially in cold weather Location : helix of ears Sx : itchy , lymphadenopathy Prog : heals in 2 weeks Tx : potent topical steroids (clobetasol), emollients, and antihistamines A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

R Raynaud’s Phenomenon Description : vasospastic event where digits change from blue to white to red Associated with : Scleroderma (CREST), SLE, Cold AIHA Reticulohistiocytoma (Solitary Epithelioid Histiocytoma) Appearance : solitary red to brown to yellow papule or nodule in adults Richner Hanhart Syndrome Appearance : dendritis keratosis, painful hands Inheritance : AR Rocky mountain spotted fever (RMSF) Etiology : Dermacentor variabilis, Dermacentor andersoni, Rhipicephalus sanguineus Description : 1. nonblanching rash initially appearing as red macules 1-5 mm in size and pruritic 2. within days the macules become papules, petechiae, and ecchymoses 3. in 50% of cases, rash becomes hemorrhagic Location : begins on the ankles and wrists, then spreads to the palms and soles To play, press and hold the enter key. To stop, release the enter key. Rosai Dorfman Disease Histo : S100+ Rosacea Etiology: increased amount of Demodex in sebaceous follicles, UV radiation, triggers (spicy food, alcohol, stress, extreme temperatures) At risk : females, Northern European Location : central face Appearance : flushing, papules, pustules, telangiectasias Ass. conditions: hyper/hypothyroid Tx : topical metronidazole, lasers, azelaic acid, doxy Rhinophyma Papulopustular Rosacea Erythematotelangiectatic Rosacea Erythematotelangiectatic Rosacea Rhinophyma Papulopustular Rosacea Papulopustular Rosacea Erythematotelangiectatic and papulopustular rosacea on the cheeks Papular rosacea on the cheeks Rhinophyma and papular rosacea on the chin Papulopustular and ocular rosacea Rhinophyma Steroid induced papulopustular rosacea Swelling and papulopustules in steroid induced rosacea Rhinophyma showing swelling and sebeceous gland openings Steroid induced rosacea on the forehead Papulopustular rosacea on the cheeks Rose Gardener’s Disease / Sporotrichosis Etiology : Sporothrix schenkii Description : multiple inflammatory subcutaneous nodules in a linear fashion along the course of the lymphatic channels Roseola / Exanthema Subitum / Sixth Disease Etiology : HHV-6 / HHV-7 Description : red lacy appearance (spares face), rose-colored macule (post high fever) Rubella / German measles / 3 day measles Etiology : Rubella Description : fine, erythematous, blanchable rash Location : begin on the face and spreads down Rubeola / Measles Etiology : measles virus (paramyxovirus) Description : diffuse, blanchable, erythematous, maculopapular rash + blue-white Koplik spots on buccal mucosa Location : rash begins at head and moving down A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

B Bacillary Angiomatosis Etiology : Bartonella henselae or Bartonella quintana + CD4 < 100; transmitted by cats or lice Appearance : erythematous to violaceous papules that grow into nodules; very friable and bleeds profusely At risk : HIV, immunosuppressed, organ transplant recipients Tx : erythromycin or doxy Bacterial Folliculitis Etiology : S. aureus , unless it is Gram negative (Escherichia coli, Pseudomonas aeruginosa, Serratia marcescens, Klebsiella or Proteus species ) or Hot tub Folliculitis (Pseudomonas aeruginosa) Appearance : follicular pustules, erythematous nodules Tx : warm compress, anti-inflammatories, mupirocin Basal Cell Carcinoma ***MC skin cancer Etiology : UV radiation, mutation in patched (PTCH) tumor suppressor gene Appearance : skin colored or pink pearly papule with rolled borders and telangiectasias Dermoscopy : sharp demarcated dark vessels Tx : excision, MOHs, cry o, PDT Behçet Disease Etiology : unknown, assumed to be connected to autoimmune response; associated with HLA-B51 Appearance : oral + genital ulcers that are 3-5 mm, round to oval ulcers with peripheral rim of erythema + yellowish adherent exudate centrally (indistinguishable from aphthous ulcers) At risk : eastern and central Asian, Mediterranean; 30-40 yo Blastomycosis Etiology : inhale spores of Blastomyces dermatitidis (found in wood and soil, on dogs) Appearance : purplish-gray verrucous lesions with heaped borders or friable lesions that ulcerate Other sx : flu-like sx, productive cough Location : face, neck, extremities At risk : south/central and mid-western America, immunocompromised, HIV Tx : itraconazole,amp B for severe disease 1/5 Blue Nevus Etiology : incomplete migration of melanocytes from neural crest to the skin during fetal development Appearance : dark blue macule, papule, or plaque Location : hands, feet, face At risk : women, asians Tx : if excised ("looks like a black hole" = super deep) Blueberry Muffin Syndrome Etiology : Rubella, CMV, tumors, blood disorders Appearance : descending blue, violaceous macule s + papules Ass. sx: anemia, hepatosplenomegaly, IUGR, jaundice Bowen disease / In situ SCC Etiology : UV radiation, HPV, arsenic exposure, immune suppression Appearance : irregular red/orange/brown scaly plaques Tx: cryo, observe, excise Bowenoid papulosis Etiology : HPV 16,18 Appearance : reddish-brown papules Location : anogenital region Tx: monitor, ED, laser, cryo 1/3 Bullous Diabeticorum Etiology : diabetes Location : lower extremities Tx : self resolving 1/4 Bullous Impetigo Etiology : S. aureus (exfoliative toxins A + B which targets desmoglein 1) Appearance : thin roofed bullae that tend to rupture spontaneously and ooze leaving a yellow crusty rim At risk : <2 yo Location : face, trunk, extremities, buttocks, perineal regions Tx: oral flucloxacillin Go to link Go to link Go to link Go to link Go to link Go to link Go to link Go to link Go to link 1/2 Bullous Pemphigoid Etiology : Autoantibodies to BP230 + BP180 (hemidesmosomes) Appearance : large, tense, fluid-filled blisters with urticarial/erythematous base Location : lower abdomen, upper thighs, or armpits; typically oral mucosa is spared Ass. with : HBV Tx: topical or systemic steroids Burns Etiology : any external heat/radiation source Types : - Superficial burn = localized, dry, blanching redness with no blisters - Superficial partial-thickness burn = blisters, blanches with pressure, swollen, warm - Deep partial-thickness burn = blisters that are easily unroofed, does not blanch with pressure and painful only to deep pressure - Full-thickness burn = white, waxy, dry, inelastic, leathery, does not blanch with pressure, painless - Deeper injury burn = white, dry, inelastic, does not blanch with pressure, painless Superficial burn Superficial burn Superficial burn Superficial partial-thickness burn Superficial partial-thickness burn Superficial partial-thickness burn Superficial partial-thickness burn Full-thickness burn Full-thickness burn Full thickness burn Full-thickness burn A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Welcome Welcome Welcome Welcome Welcome to DalyDermatology! 💖 Join me on my journey as a medical student exploring the science behind healthy, radiant skin—and working to make dermatology more inclusive for everyone. Inspired by the lack of diverse skin images in medical education, I created Daly’s Diverse Dermatology Dictionary: a free resource showing how skin conditions appear across all skin tones. My passion is to bridge gaps in knowledge, encourage equity, and help our medical community better serve every patient. Thanks for being here—let’s learn and grow together! ✨ Check out my most recent blogs! Let Me Catch You Up 🤍 The past few months have been full: audition rotations, applications, interviews, and quiet growth behind the scenes. In this post, I’m catching you up on the reality of dermatology and TY interview season, what this stretch has taught me, and why sometimes the quiet seasons are the ones building the strongest foundation. Step 2 CK Exam Day: What I Wear, What I Pack, and How I Stay Focused Wondering what to wear, pack, and do on Step 2 CK exam day? I break down my morning routine, must-have snacks, bag essentials, and in-exam strategies for staying sharp and confident. Get my real-life tips for managing nerves and maximizing performance on test day! Derm Dream Bag: My Dermatology Audition Rotation Essentials Discover the ultimate dermatology audition bag essentials! From pink Vaseline and L’Oréal lip gloss to study guides, sunscreen, meds, and snacks—this tote is packed for a busy med student’s clinic day. Stay prepped, polished, and confident with these must-haves in your Poppy & Peonies tote. Bridging the Gap: Daly's Diverse Dermatology Dictionary After realizing most dermatology images in my training only showed conditions on white skin, I began collecting and organizing photos of skin diseases across all skin tones. This project grew into Daly’s Diverse Dermatology Dictionary—a free, ever-expanding resource designed to fill this gap and help students, clinicians, and educators recognize skin diseases on every patient. My goal is to make dermatology education more inclusive, accurate, and truly reflective of the diversity in our world, so we can provide better, more equitable care for all. Click Here Follow me on Instagram @dalyderm Load more

D Darier Disease / Keratosis Follicularis Etiology: mutation of ATP2A2 gene Inheritance : AD Appearance : scaly crusted papules and greasy plaque; alternating red + white nail beds with V-shaped nicking Location : seborrheic dermatitis distribution (oily areas of the body like chest, back, scalp margins, forehead, nasolabial folds, eyebrows, beard) and skin folds At risk : adolescents Tx : moisturizers, topical retinoids, sun protection Dermatitis Herpetiformis Etiology: cross-reactivity between anti-gliadin IgA antibodies + transglutaminase at the dermal basement membrane Appearance : papulovesicles or excoriated papules on erythematous base Location : elbows, dorsal forearms, knees, scalp, buttocks Sx : intense itching At risk : pts with Celiac Disease, Irish or Swedish patients Associated with : maltomas Tx : gluten free diet, dapsone Dermatofibroma Etiology : trauma (mosquito bite, shaving nick) Appearance : tan to pink, firm, hyperpigmented dome-shaped papules with peripheral rim of darkening pigment Location : extremities Prog : once you get one, you're at risk of getting more Dermoscopy : peripheral fine network, central white or pink scar-like area, ring-like globules, dotted vessels At risk : adults Test : "dimple or pinch" sign Tx : reassurance Dermatofibrosarcoma protuberans Etiology : rare type of skin cancer characterized by its slow-growing, locally aggressive nature; unknown cause, but an injury is a predisposing factor Appearance : skin colored, pink or brown irregular border multi nodular fungating mass Histo : storiform spindle cells very deep with fat getting trapped in it Sx : painless plaque +/- nodules that feels rubbery or firm to touch At risk : adults between 20- 60 yo Location : trunk Tx : MOHs favored over wide excision; imatinib if t17;22 To play, press and hold the enter key. To stop, release the enter key. Dermatographia Etiology : skin trauma may release an antigen that reacts with the membrane bound IgE on mast cells triggering histamine release Appearance : linear wheals + a surrounding erythematous flare which appears 1-3 minutes after stroking + resolves in 30-60 minutes At risk : young adults Tx : loose fitting clothes, avoid triggers, antihistamines, phototherapy, omalizumab 1/7 Dermatomyositis Etiology : unknown; classic model considers DM to be the result of a humoral attack against the endothelium of muscle capillaries + small arterioles; risk factors include underlying malignancy + family hx of autoimmune disease At risk : 30-50 yo, females Sx : rash appears weeks to months before proximal muscle weakness Locations : extensor surfaces of MCP + IP = Gottron papules upper eyelids = Heliotrope malar-like rash chest = V neck sign = Poikiloderma upper back = Shawl sign lateral thigh = Holster sign Ass. conditions : adenocarcinomas Tx : systemic CS Go to link Go to link Go to link Go to link Go to link Go to link Go to link Go to link Go to link 1/3 Dermatophytosis / Tinea / Ringworm Etiology: Trichophyton, Epidermophyton, Microsporum Appearance : annular erythematous plaque with central clearing and raised scaly edge Sx : itchiness Locations : tinea barbae = beard tine a c apitis = head tinea corporas = body tinea cruris = groin tinia unguium = nails tine a pedis = foot At risk : hot humid climates Tx : topical antifungals (imidazole, terbinafine) unless if it is on head or nails (oral instead: itraconazole, itraconazole) Dermatosis Papulosa Nigra Etiology : activating mutation in FGFR3 Appearance : 1-5 mm in diameter, hyperpigmented brown-black sessile to filiform, smooth surfaced papules Location : cheeks, temples At risk : Fitzpatrick types 4/5/6, females Tx : EDC (for darker skin), cryo (for lighter skin), Nd:YAG laser 1/10 Diffuse Palmoplantar Keratoderma (DPK) Etiology: genetic abnormality Inheritance : AR or AD Appearance : hyperkeratosis with white/yellow hue Sx : hyperhidrosis Location : symmetric palmar + plantar surfaces Tx : emollients, keratolytic agents ( salicylic acid, propylene glycol), topical retinoids, oral retinoids (acitretin), topical vitamin D (calcipotriol) Disseminated Superficial Actinic Porokeratosis (DSAP) Etiology: mutation in: MVD, MVK, FDPS, PMVK or SART3 genes; results in decreased cholesterol in the affected areas of the skin Inheritance : AD At risk : European, females Locations : arms, legs Appearance : irregular annular plaque with elevated horny rim Prog : <10% turn into SCC Tx : compounded off-label topical 2% lovastatin +/- topical cholesterol, sun protection education Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) Etiology: delayed type IV HS reaction to certain medication ( anti epileptics , allopurinol, sulfonamides, minocycline, HIV meds) Appearance : facial edema, diffuse erythematous macules + plaques that typically occur in 3rd week after starting a med or increasing dose Ass. sx : high fever, lymphadenopathy, hematological abnormalities, hepatitis, nephritis, carditis, other organ involvement, facial swelling Location : first involves face, upper trunk, UE, and then spreads to LE Tx : stop all suspect medications, systemic CCS, cyclosporin, IVIG Dyshidrotic Eczema Etiology : unknown Location: palms, fingers, soles of feet Sx : extremely itchy chronic, recurrent Appearance : recurrent fluid-filled vesicles that resolve after several weeks with scaling Tx : clobetasol + tacrolimus; severe = Dupixent Dyskeratosis Congenita (DC) Etiology : 14 different genes (DKC1 gene mutations on X chromosome); causing telomere shortening = premature aging Inheritance : AD or AR Appearance : lacy reticular hyperpigmentation Other sx : nail dystrophy, oral leukoplakia, early hair greying, sparse eyelashes, hyderhidrosis Location : upper chest, neck, nail atrophy, oral leukoplakia Tx : no cure; tx is aimed at maintaining bone marrow function via oxymetholone as this is the major cause of death A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Explore Daly’s Diverse Dermatology Dictionary: an inclusive resource with dermatology images on a range of skin tones for better, equitable medical education. Welcome to: Daly's Diverse Dermatology Dictionary By Letter... A H O V B I P W C J Q X D K R Y E L S F M T G N U Z Welcome! I’m so grateful you’re here. This resource was created with one goal in mind: to help bring greater diversity, accuracy, and inclusivity to dermatologic education. From my very first year in medical school, I noticed a glaring omission in our training, most dermatology images we learned from depicted conditions only on white skin. When darker skin tones were included, it was often only for diseases commonly associated with those populations, such as lupus or sarcoidosis. I searched everywhere for a comprehensive, side-by-side visual guide showing both common and uncommon conditions across the full range of skin tones… but that resource simply did not exist. What started as a personal frustration quickly turned into a mission. Throughout medical school, I began collecting and organizing photographs of dermatologic conditions in patients of all skin tones, building a databank to deepen my own learning. When classmates saw and used these materials, the response was immediate gratitude, surprise that such a tool wasn’t standard, and encouragement to make it something bigger. After hundreds of hours and countless images, I’m proud to share this passion project publicly: Bridging the Gap: Daly’s Diverse Dermatological Dictionary . It is not a fully exhaustive dermatology textbook, but rather a concise, essential, and intentionally curated resource highlighting the facts, visuals, and patterns I find most important, especially for medical students and early healthcare trainees. My only goal is to support better recognition of skin disease in EVERY patient. I have no financial disclosures, no sponsors, and no conflicts of interest. This work is created purely out of a commitment to more equitable, accurate medical education. Your enthusiasm fuels my own, and I’m honored to share this growing project with you. Important Note: Sensitive Content This educational resource includes clinical photographs of sensitive areas, including genitalia, when medically relevant. Viewer discretion is advised. Educational Purpose & Legal Disclaimer This dictionary is intended solely for educational purposes. It is NOT designed or approved for diagnosing, treating, or managing any medical conditions in real patients. Nothing in this document should be interpreted as medical advice, a treatment recommendation, or a substitute for professional clinical judgment. By accessing or viewing this dictionary, you acknowledge and agree that: You understand this resource is for educational enrichment only. You will not use any content within this document to diagnose or treat patients. The author (Paige Daly), DalyDerm, and all affiliated platforms assume no responsibility for clinical decisions made based on this material. All information is presented “as is” and without any warranty regarding accuracy, completeness, or fitness for a particular purpose. Dermatology is a constantly evolving field; details may change with new research, and occasional errors or omissions may occur despite best efforts. You agree to use this resource ethically, responsibly, and within your scope of training. If you believe something here is incorrect or have concerns about a specific entry, please reach out to me at dalydermatology@gmail.com so I can review and update the material accordingly. The author assumes no liability for any direct, indirect, incidental, or consequential damages arising from the use, or misuse, of this dictionary. By continuing to use this dictionary, you accept these terms fully. Welcome to a more inclusive way of learning dermatology. Thank you for being part of the movement to bridge the gap, together. Please enjoy, share widely, and if you’d like a downloadable version, scroll to the bottom. Your enthusiasm fuels my own, and I’m grateful to share this journey with you. — Paige O’Brien Daly, MA Creator of DalyDerm & Dermatology Educator Submit Your Own Photo Please take a moment to fill out the form. First Name Last Name Email Diagnosis Leave us a message and include: (1) that you consent to allowing me to use your photo within my dictionary (2) the photo and diagnosis. Submit Thanks for submitting!

P Paget disease Etiology : DCIS Description : erythematous, pruritic, ulcerated skin at the nipple and breast Palmoplantar Verruca Appearance : thick, endophytic papules Papillary Hidradenoma / Hidradenoma Papilliferum Etiology : unknown cause; thought to arise from anogenital mammary-like glands Description : slow-growing painless, firm, flesh to red nodule Location : labia majora + interlabial folds Papillon-Lefure Syndrome Appearance : hyperhidrosis + periodontitis with severe gingivitis Inheritance : AR Peau d’orange Etiology : blockage of lymphatic drainage with or without associated stromal infiltration; inflammatory breast cancer Description : thick and pitted, with a texture and appearance similar to that of orange peel Pemphigoid Gestationis / Herpes Gestationis Etiology : IgG autoantibodies that target BP180 Appearance : erythematous papules or plaque around the umbilicus + then spreads to most areas of body, but sparing face + mucous membranes; 2-4 weeks later large, tense bullae form Sx : intensely itchy Tx : high potency topical CS, but many end up requiring oral CS Risk to fetus = prematurity Pemphigus Foliaceus Etiology : IgG autoantibodies to desmoglein 1 At risk : Tunisia Appearance : flaccid, superficial bullae that rupture easily Location : seb derm distribution (NO oral lesions) Tx : systemic CS Pemphigus Vegetans Locations : Intertriginous Pemphigus Vulgaris Etiology : IgG autoantibodies to desmoglein-1 and/or desmoglein-3; can be triggered by meds (#1 captopril + penicillamine) Location : mucosal membrane + skin Appearance : flaccid bullae that easily rupture (+ Nikolsky sign; + Asboe-Hansen sign) Sx : extremely painful At risk : middle aged to young adults ; Ashkenazi Jews Tx : systemic CS Periorificial Dermatitis Tx : taper steroids, oral tetracycline, topical metronidazole, erythromycin, tacrolimus Petechiae Description : Tiny 1-2 mm, initially purpuric, non-blanchable macules resulting from tiny hemorrhages Peutz-Jeghers Syndrome (PJS) Etiology : mutations in serine/threonine kinase 11 (STK11) Inheritance : AD Description : Tan, dark brown, or bluish black flat patches 1 to 5 mm in size Location : around the mouth, lips, gums, inner lining of the mouth, eyes, hands and feet, fingers and toes, anus and genital areas Associated with : GI polyps Piebaldism Define : rare, inherited genetic disorder characterized by patches of skin and hair that lack pigment Etiology : mutation inactivating c-KIT gene Inheritance: AD Description : white forelock with white patches of skin Location : face (chin), trunk, + distal extremities Pigmentary Demarcation Line Define : abrupt transition between areas of darker and lighter pigmentation At risk : darker skin tones Pigmented DFSP (Bednar tumor) At risk : African American Pigmented Purpuric Dermatosis (PPD) Appearance : reddish-brown patches and spots Etiology : results from capillary inflammation and leakage of red blood cells, leading to hemosiderin deposits Location : lower legs Tx : topical corticosteroids, compression stockings Pilar Cyst / Trichilemmal Cyst Etiology : keratin-filled cyst that originates from the outer hair root sheath; typically running in families (AD) Description : one or more firm, mobile, subcutaneous nodules measuring 0.5 to 5 cm in diameter and without a central punctum Location : typically scalp Pilomatricoma Define : benign (non-cancerous) skin tumor that arises from hair follicle cells Appearance : small, hard, and slow-growing lump teeter toter sign Location : head or neck Histo : ghost cells Pityriasis Alba Etiology : unknown; coexists with dry skin and atopic dermatitis Description : hypopigmented patches that are round or irregular in shape and up to 5 cm in diameter Locations : typically appear on face, especially cheeks and chin Pityriasis Lichenoids Et Varioliformis (PLEVA) Etiology: Pityriasis Rosea Etiology : not clear; some suggest HHV-6 or 7 At risk : older children + young adults Appearance: begins with a single "herald patch" or "mother patch" which is a salmon colored oval plaque, usually on neck, back or chest. Patch becomes scaly and develops central clearing, forming "collarettes of scale." Then numerous similar but smaller patches. appear on trunk + extremities following skin tension lines (Christmas tree distribution). Tx : only topical CS to relieve pruritus Pityriasis (Tinea) Versicolor Etiology : Malassezia furfur or Malassezia globosa Appearance : hyper or hypo pigmented or salmon colored scaly patches Location : sebum rich areas Tx : selenium sulfide, ketoconazole shampoo, topical or oral azoles Pitysporum Folliculitis Dermatoscope : spores grouped together in hair follicle POEMS Syndrome Description : hyperpigmentation, hemangiomas, hypertrichosis, and scleroderma-like skin thickening Polyarteritis Nodosa (PAN) Etiology : Medium vessel vasculitis Description : lace like rash (livedo reticularis) + ischemic digits Associated with : HBV, acute mesenteric ischemia Polymorphic Eruption of Pregnancy (PEP) / Pruritic Urticarial Papules and Plaques of Pregnancy (PUPPP) Sx : onset of late 3rd trimester Location : starts within abdominal striae with periumbilical sparing RF : primigravid preg, multiple gestation preg Does not affect development Tx : topical steroids, non-sedating oral antihistamines, oral pred Polymorphous Light Eruption (PMLE) Appearance : erythematous papules, vesicles, plaque on sun exposed skin only Tx : antihistamines (Zyrtec and Benadryl), steroid injection in office Etiology : stretching of the skin elicits an immune response due to connective tissue damage Description : itchy, bumpy rash that starts in the stretch marks of the abdomen Poroma Etiology: Location: plantar surface Porphyria Cutanea Tarda Etiology : mutation in UROD gene = affecting uroporphyrinogen decarboxylase = accumulates uroporphyrin Inheritance : AD Description : blistering cutaneous photosensitivity and pigmentation Port-wine stain / Nevus flammeus Etiology : vascular malformation of capillaries and post capillary venules in dermis Appearance : pink, red, or violaceous sharply demarcated patches that darken + thicken overtime Location : face, unilateral Tx : PDL Prog : persist throughout life + grow proportionally with child Pretibial myxedema / thyroid dermopathy Etiology : dermal fibroblasts Description : plaques of thick, scaly skin and swelling Location : lower legs Associated with : Graves disease (hyperthyroidism); if not at pretibial region = related to hypothyroidism Primary Cutaneous Anaplastic Large Cell Lymphoma (ALCL) Etiology : t(2;5)(p23;q35) translocation resulting in a fusion gene product of receptor tyrosine kinase ALK with nucleophosmin Description : rapidly-growing single nodule or plaque that typically is red to violaceous, at least 2 cm in diameter, and often ulcerates Location : upper half of the body is most commonly involved At risk : 50+ yo males Proteus syndrome Etiology : mosaic non inherited mutation in AKT1 gene Appearance : port wine stains Location : limbs, digit, skull Prog : at risk for developing DVTs, PEs Prurigo Nodularis Sx : intensely itchy, firm nodules; can be extremely uncomfortable, impacting sleep and potentially leading to anxiety and depression Tx : JAK-I, ILK Pseudofolliculitis Barbae / Razor Bumps Etiology : shaving, which lead to ingrown hair Description : firm, hyperpigmented papules and pustules that are painful and pruritic Location : face + neck At risk : African American males Psoriasis Appearance : well demarcated pink erythematous plaque with silver scale Nail changes : pitting, onycholysis, subungal hyperkeratosis, oil drop sign (yellow-orange discoloration) Tx : localized: high potency steroid +/- topical vitamin D other options: tazarotene, calcineurin inhibitors, Taltz, Otezla (apremilast), Skyrizi, Tremfya Etiology : T cells triggered (stress, skin injury, infection, cold, dry weather, tobacco) to attack skin cells Description : dry, raised skin patches (plaques) covered with gray or silver scales Location : hairline, elbows, knees (extensor surfaces) Purpura Description : 4 - 10 mm in diameter, flat, and red, purple in color Pustular Psoriasis Sx : presents in 3rd trimester Appearance : symmetric erythematous plaques with pustules that start in flexural areas and spread centrifugally Location : trunk and extremities Ass sx : fever, malaise, nausea, vomiting, anorexia Tx : CCS, low dose cyclosporine, infliximab Prog : increased risk to fetus Etiology : triggers from infections, stress, corticosteroid treatment withdrawal, and pregnancy Description : pus-filled blisters on plaques, which are patches of scaly, flaky skin Pyoderma Gangrenosum Description : painful, symmetrical necrotic base that progresses over 1 month Location : legs Associated with : IBD Pyogenic granuloma / Capillary lobular hemangioma Etiology : mutation in BRAF plays a key role; medications (retinoids, TK inhibitors), trauma, laser therapy At risk : 20-30 yo Appearance : small red papule that grows over several weeks into a nodule Location : hands, lower lip, gingiva Tx : full thickness excision or shave excision for pedunculated lesions A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A Acanthosis Nigricans Etiology: insulin resistance Appearance : hyper pigmented leathery plaque Location : back of the neck, axilla, groin Associated with : gastric or lung adenocarcinoma, Cushing Syndrome, PCOS, diabetes, obesity Tx : treat underlying condition Acanthosis Palmaris / Tripe Palms Etiology: internal malignancy Appearance : thickened velvety pattern of skin often gives a yellow hue to the skin Location : palms and dorsal hands, soles of feet At risk : males Associated with : bullous pemphigoid, psoriasis Tx : treat malignancy Accessory Tragus Define : common, benign, congenital anomaly of the ear Appearance : small, skin-colored nodule Location : anterior to tragus Tx : excise Acne Keloidalis Nuchae Etiology: short hair cuts, friction from headgear or collars Appearance : flesh colored, dome shaped papules + pustules Sx : itchy Location : posterior scalp + neck At risk: African-Caribbean descent with dark curly hair Tx : change hairstyle, reduce friction, mild to moderate steroids with topical retinoids, oral doxy Acne Vulgaris Etiology : folliculosebaceous unit is blocked, swollen, ruptures, and inflames the surrounding skin Location : face, chest, upper back At risk : oily skin, teenagers Tx : tretinoin, adapalene, doxy, spironolactone, OC Ps , isotretinoin Types : comedones: open and closed papules pustules nodules Acrochordons / Skin tags Etiology: excess friction, insulin intolerance Appearance: skin colored pedunculated, fleshy papules Location : high friction areas like under breast, neck, axillae, groin Associated with : obesity, diabetes, pregnancy, acromegaly Tx: snipping, LN, ED Actinic Keratosis (AKs) Etiology: sun exposure Appearance: pink/hyperpigmented thin scaly plaque Location : sun exposed areas Prog : 10-15% turn into SCC Tx: cryo, 5-FU, imiquimod, PDT African Trypanosomiasis Etiology: T.b. rhodensiense, T.b. gambiense Appearance: - At site of Tsetse fly bite, chancre forms with enlarged lymph nodes - 2-3 weeks later, a central necrotic eschar forms - 6-8 weeks later, trypanids form (red patches, urticaria, targetoid lesions) Tx : before the meningoencephalitic phase = suramin; meningoencephalitic phase = melarsoprol 1/3 AL Amyloidosis Etiology: accumulation of an immunoglobulin light chain (lambda > kappa) protein Appearance: waxy skin with periorbital purpura (ex: Raccoon eyes) Tx : high dose plasma cell directed chemotherapy with melphalan and dexamethasone Albinism Etiology: mutation of OCA 1A, OCA 1B, and OCA 2 (oculocutaneous) = decreased tyrosine activity or defective tyrosine transportation Inheritance : AR Appearance: diffuse depigmentation Allergic Contact Dermatitis Etiology: type IV hypersensitivity reaction to allergen (nickel, poison ivy, PCN, detergents) Appearance: erythematous vesicular rash with edema Tx : find causative agent and avoid, emollients and topical steroids Go to link Go to link Go to link Go to link Go to link Go to link Go to link Go to link Go to link 1/2 Alopecia Areata Etiology : autoimmune condition Appearance : hairless, smooth patches without scale, erythema, or inflammation Test : positive hair test at periphery Ass. conditions : autoimmune disorders, Down syndrome , atopy Dermoscopy : exclamation point hairs Tx : topical clobetasol solution , minoxidil, intralesional triamcinolone Angioedema Etiology: increase in local capillary permeability, usually mediated by mast cells, histamine, or bradykinin release Appearance : swelling of dermis and SQ tissue Location : eyes, lips, genitals At risk : pts with chronic urticaria Sx : painful or burning, but not pruritic Tx : antihistamines for mild acute cases, oral prednisone for more severe cases, TXA or omalizumab for refractory recurrent angioedema Angiosarcoma Etiology : 20% have history of radiation to head or neck Appearance : blue or purple macular, sometimes raised or nodular; often become ulcerated or hemorrhagic Location : face + scalp Tx : complete resection with wide margins Prog : 5 yr survival is ~35% Angular Cheilitis Etiology: most commonly occurs due to prolonged exposure of the corners of the mouth to saliva and its digestive enzymes Appearance : erythematous fissuring, thin scales and crust Location : corner of mouth At risk : pts with poor health Ass. conditions: iron deficiency anemia, vitamin B deficiencies, protein malnutrition, chronic inflammatory diseases (IBD, Crohn Disease, Sjogren Syndrome) Tx : most cases resolve by itself, improve hydration, lip emollients 1/8 Aphthous Ulcer / Canker Sore Etiology : unknown antigen stimulates keratinocytes via increase pro-inflammatory cytokines Triggers : emotional stress, lack of sleep, mechanical trauma, nutritional deficiency, viral infections, certain foods or toothpastes Appearance : round to oval ulcer with peripheral rim of erythema + yellowish adherent exudate centrally Location: mucosa of lips, oral mucosa, tongue margins Tx : heals spontaneously, avoid triggers Aplasia cutis Etiology : intrauterine trauma, vascular compromise, infection (HSV, VZV), meds (methimazole), Patau syndrome (on occiput) Appearance : well-demarcated erosion or ulcer with loss of hair Tx : heal spontaneously Arsenical keratosis Define : development of thickened, wart-like growths on the skin due to chronic arsenic exposure Appearance : multiple, small, yellowish, and horny ( keratotic) papule s or plaques Location : palms + soles At risk : farmers, well water use Tx : cyro, ED, 5-FU, imiquimod, oral retinoids Arterial Ulcer Etiology : peripheral artery disease (atherosclerotic stenosis) Appearance : well defined punched out ulcer At risk : pts that smoke, have DM, high BP, high cholesterol, RF, RA, obesity Location : distal toes Tx : lifestyle changes, wound care Go to link Go to link Go to link Go to link Go to link Go to link Go to link Go to link Go to link 1/2 Atopic Dermatitis / Eczema Etiology : type 1 HS reaction associated with other atopic diseases; loss of function of FLG gene = mutation in filaggrin Appearance : irregular border pink plaque with scale +/- lichenification Location : flexural surfaces (adults) vs extensor surfaces (children) At risk : ‘atopic tendency’ clustering with hay fever, asthma, and food allergies Tx : avoid skin irritants, emollients, topical steroids, bleach baths, tacrolimus, Dupixent, Nemolizumab, and so much more Prog : 20% of children with AD had persistent sx 8 years later; children who developed AD before 2 yo had a lower risk of persistent sx than those that developed AD later in life Atopic Eruption of Pregnancy (AEP) / Prurigo of Pregnancy Etiology : pregnancy causing cytokine imbalance Appearance : hyper pigmented or erythematous papules that are often grouped together Location : extensor surfaces At risk : 2nd - 3rd trimester Prog : no increased risk to fetus, resolve after pregnancy Tx : topical steroids, benzoyl peroxide, emollients 1/5 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

X Xanthoma Etiology: disorders of lipid metabolism (dyslipidemia) or occur in histiocytosis; accumulation of fat in macrophages Appearance : soft, yellow or skin colored papules or plaques Location/Types: medial canthus of upper eyelid = xanthelasma over pressure areas (knees, elbows, heels) = tuberous xanthoma extensor surfaces (buttock, shoulders) = eruptive xanthoma Tx: treat underlying dyslipidemia +/- chemical peels, electrodessication, cryo, excision Xeroderma Pigmentosum (XP) Etiology: mutation in nucleotide excision repair (NER) + UV rays Inheritance: AR Appearance : born with normal skin, but with increased sun exposure, patients develop hyperpigmented and hypo pigmented macules Location : sun exposed skin Tx : no cure, prevent UV exposure Prog : premature aging; die earlier from skin cancers Xerosis Cutis/Dry Skin Etiology: skin is lacking moisture in stratum corneum Appearance : rough, scaly plaque At risk : everyone 60+ yo, AD, hypothyroidism, CKD, weight loss Tx : moisturizers + emollients Go to link Go to link Go to link Go to link Go to link Go to link Go to link Go to link Go to link 1/2 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z