S
Salmon patch / Nevus simplex
Etiology: vasomotor immaturity
Appearance: pink to red blanchable patches
Location: nape of neck, eyelids, glabella
Tx: none
Prog: fades within first 2 yrs of life










Scabies
Etiology: Sarcoptes scabiei
Appearance: scattered pink papules, burrows, vesicles, and excoriations
At risk: living in close quarters (dorms, nursing homes, homeless)
Location: web spaces of fingers, umbilicus, belt line, groin, axillae
Tx: 2 doses of permethrin given 10 days apart or with oral ivermectin




Scalded Skin Syndrome
Etiology:
Cause: S. Aureus (exfoliative toxin)
Description: red rash with wrinkled tissue or paper-like consistency that typically starts on the face and flexural regions, then spreads rapidly to other parts of the body; bullae can form post-rash and easily rupture causing sloughing of the skin in large sheets
At risk: <5 yo, RF immunosuppressed, DM
Location: skin folds and then disseminates in 48 hrs
Tx: burn unit/ICU, IV abx
Scarlet fever / Second Disease
Etiology:
Cause: S. pyogenes (exotoxins A, B, C)
Description: fine blanching rash post sore throat; “goose skin or sandpaper like”

Sebaceous Hyperplasia
Etiology:
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Appearance: skin-colored or yellowish umbilicated papules
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Vs. BCC – pearly, waxy with telangiectasia that will bleed or scab easily
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Prog: expect more in coming years
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Dermoscopy: “crown vessel” pattern with vessels that are blurry and restricted to the periphery
Seborrheic Dermatitis
Etiology:
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Appearance: erythematous patches with overlying scale; greasy yellow plaque with scale
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Location: scalp, eyebrows, eyelids, nasolabial folds, external auditory canal, central chest
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Tx: ketoconazole twice daily, desonide cream twice daily for 1-2 weeks, antidandruff shampoo
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Cause: increased activity of sebaceous glands due to presence of Malassezia
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Description: erythematous, well-demarcated plaques with greasy yellow scales in areas rich in sebaceous glands; worsens in winter and early spring; in darker skin, the plaques and scales can make the skin appear lighter
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Location: scalp, face, periocular
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Associated with: Parkinson’s Disease
Seborrheic Keratosis (SK)
Etiology: mutations in FGFR3 genes
At risk: > 30 yo
Appearance: "stuck on" appearing warty plaque or patches
Dermoscopy: moth eaten borders, keratin pseudocysts
Tx: cryo (light skin), EDC (darker skin)
Senile Purpura
Etiology: steroids, blood thinners, poor nutritional status, fair skin, age
Location: dorsal hands, forearms
Tx: none




Sézary Syndrome
Etiology:
Cause: unknown
Description:
Lighter skin = diffuse red rash with pruritis and edema covering >80% of body.
Darker skin = gray, purple or brown.
Early symptoms of rash appears like eczema or psoriasis
At risk: elderly




Sjögren-Larsson syndrome
Etiology:
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Define: rare genetic disorder characterized by ichthyosis (scaly skin), intellectual disability, and spasticity
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Etiology: deficiency in fatty aldehyde dehydrogenase (FALDH), which is encoded by the ALDH3A2 gene
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Inheritance: AR
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Tx: leukotriene B4
Skin Tags / Acrochordons / Fibroepithelial Polyp
Etiology:
Cause: excess friction
Description: smooth or slightly wrinkled, flesh-colored, or darker, and hanging off the skin by a small stalk
Locations: areas of high friction: armpits, under breasts, groin, neck
Associated with: obesity, diabetes, pregnancy, acromegaly










Smallpox
Etiology:
Cause: smallpox virus
Description:
1. after 2-4 days of fever, body aches and headache, a rash develops
2. rash becomes raised bumps that then become fluid-filled with a depression in the center (umbilicated)
3. bumps turn into pustules that are raised, round and firm to touch
4. after about 5 days pustules begin to form a crust and then scab
5. scabs fall off leaving marks on the skin that eventually become pitted scars
Location: Rash spreads to face, arms, legs, hands and feet and to all parts of the body within 24 hours
Solar Elastosis / Actinic Elastosis
Etiology:
Cause: chronic sun damage + smoking
Description: dry, thick, and yellow skin, with bumps, wrinkles, or furrowing
Solar Lentigo / Sun spot
Etiology:
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Appearance: hyperpigmented macules and patches
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Tx: bleaching creams, LN, chemical peels, lasers
Solitary (Juvenile) Xanthogranuloma (JXG)
Etiology:
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Appearance:
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Histo: touton giant cells, lots of eos
Spider angioma / Spider naevus / Spider telangiectasia
Etiology:
Cause: increased estrogen
Description: spider webs or tree branches (arteriole)
Associated with: liver cirrhosis + pregnancy
Spitz nevus
Etiology:
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Appearance: raised, dome-shaped mole, typically reddish or pinkish
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At risk: children + young adults
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Vs. melanoma due to appearance
Splinter hemorrhages
Etiology:
Cause: S. aureus (mostly), S. viridans (anything that can increase IC deposition)
Description: linear hemorrhage lesions
Location: nail bed




Squamous Cell Carcinoma (SCC)
Etiology: UV exposure over a lifetime
Location: lower legs (women), chest/back (men)
At risk: Fitzpatrick types I + II, smoking, arsenic exposure, immunosuppression, scars, tanning bed use, HPV infection
Appearance: firm, skin to pink colored, infiltrative papule or plaque that is sometimes ulcerated or covered in crust
Dermoscopy: focal scale, glomerular vessels, pinpoint hemorrhages, central keratin mass, hairpin vessels
Tx: excision, Mohs, radiation or cryo in select cases
Stevens-Johnson Syndrome (SJS) / Toxic Epidermal Necrolysis (TEN)
Etiology:
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Sx: fever, HA, rhinitis, and myalgias precede mucocutaneous lesions by 1-3 days; eruption initially symmetric and pain is a prominent symptom
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Location: face, upper trunk, proximal extemities
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Appearance: erythematous irregularly shaped, dusky red to purpuric macules with dark center which progressively coalesce; + Nikolsky sign
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SJS <10% TEN >30%
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Tx: stop drug, go to a burn unit, IVIG, IV CS
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Cause: type IV HS drug reaction
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Description: circular non-pruritic rash that is darker in the middle and lighter on the border; progresses to blisters and sores which are painful and easily peel
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Location: usually starts on the upper body before quickly spreading to the face, arms, legs, genitals + mucosal surfaces
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Associated with: TEN (SJS that covers >30% of body surface)
Strawberry / Infantile Hemangioma
Etiology: expresses higher levels of vasculogenic factors than normal tissue (VEGF)
Appearance: well-defined bordered erythematous papules or nodules
At risk: before 4 weeks of age
Location: head + neck
Tx: most are self resolving; if it is high risk (airway, liver, GI involvement, periorbital, PHACE syndrome, rapidly growing) then oral propranolol
Prog: involution typically begins between 6-12 mo of age
Stucco keratoses
Etiology:
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Appearance: small white-gray SKs
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Location: dorsal feet/ankles
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At risk: older light-skin
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Tx: cryo, curettage, ED, Amlactin
Sturge-Weber syndrome
Etiology:
Cause: somatic mosaicism of activating mutation in 1 copy of GNAQ gene
Description: port-wine stain in trigeminal nerve territory
Sweet Syndrome / Acute febrile neutrophilic dermatosis
Etiology:
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Appearance: sudden onset of painful, red or purple, “juicy”, raised lesions (plaques, papules, or nodules)
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Sx: fever
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Ass. conditions: infections, IBD, + hematologic malignancies
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Tx: pred
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Cause:
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Description: erythematous, edematous, well-demarcated, tender plaques that are asymmetrically distributed
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Location: face, neck, + upper extremities
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Associated with: IBD




Swimmer’s Itch / Cercarial Dermatitis
Etiology:
Cause: Schistosoma mansoni
Description:
1. occurs within hours of exposure after the film of water has dried on the skin
2. itch or a tingling sensation which settles quickly, leaving tiny red spots where skin penetration by the cercariae/larvae
3. Intense itch develops over hours and the red spots can enlarge to form papules and hives
4. Blisters may develop over the next 24 to 48 hours
At risk: anyone swimming in waters with infested snails












Syphilis
Etiology: Treponema pallidum pallidum
Appearance:
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primary = chancre (firm, painless, oozes fluid)
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secondary = maculopapular rash including palms + soles; condylomata lata (smooth, painless, warlike white lesions on genitals)
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tertiary = gumma
Tx: penicillin
Systemic Lupus Erythematosus (SLE)
Etiology: systemic autoimmune condition
Types/Appearance:
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Acute cutaneous LE: butterfly/malar rash that spares nasolabial folds
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Subacute cutaneous LE: annular scaly erythematous macules + plaques on head + extremities
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DLE: pink infiltrative scaly patches + plaques that heal with atrophy, depigmentation, scarring
Tx: antimalarials, CS, immunosuppressants, dapsone
Systemic Scleroderma (SSc)
Etiology:
Cause: autoimmune condition with noninflammatory vasculopathy and collagen deposition with fibrosis (anti-Scl-70 Ab, anti-RNA polymerase III Ab, anti-centromere Ab)
Description:
Limited SSc = only involving fingers and face = calcinosis cutis, Raynaud phenomenon, sclerodactyly, telangiectasia
Diffuse SSc = widespread skin thickening, shiny appearance, feeling of tightness + visceral involvement; sometimes have a “salt and pepper” appearance on darker skin
Syringoma
Etiology:
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Define: benign skin growths that originate from sweat ducts
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Appearance: small, skin-colored or yellowish bumps
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Location: clustered around the eyes, but can also occur on neck, chest, abdomen, and genitals
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Cause: overgrowth of eccrine sweat glands
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Description: firm bump that resembles a pimple (papule) on your skin that usually forms in small clusters or groups on your skin
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Location: face (lower eyelid + upper cheeks)
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Ass: Down syndrome











































