Dermatology Emergencies Pearls Key points for your Board Review

• Urticarial (hives) lesions are transient (<24hours), nonsymmetric, pruritic plaques.
• Erythema multiforme rash is fixed, symmetric, nonpruritic, target lesions, and can be found on the palms/soles.
• Erythema multiforme is commonly caused by drugs and herpes simplex virus; the treatment is supportive (treat underlying cause) and course is benign.
• Erythema multiforme does NOT involve mucous membranes.
• Stevens Johnson Syndrome is commonly caused by drugs (to a lesser extent herpes simplex and mycoplasma).
• Stevens Johnson Syndrome has a flu-like prodromal illness, mucosal membrane involvement (classically conjunctiva/mouth), with POSITIVE Nikolsky sign, with <10% body surface area involvement.
• Stevens Johnson Syndrome INVOLVES mucous membranes, and the treatment is supportive (remove underlying cause).
• Toxic Epidermal Necrolysis is almost universally caused by drugs, with a flu-like prodromal illness, mucosal membrane involvement, POSITIVE Nikolsky sign, with >30% body surface area involvement.
• The most common class of drugs that cause SJS/TEN = sulfa.
• Staph Scalded Skin Syndrome is classically in young children (<6 years old), associated with PAINFUL erythema/bullae and POSITIVE Nikolsky sign.
• Staph Scalded Skin Syndrome does NOT involve mucous membrane.
• Meningococcemia rash is diffusely petechial that evolves into palpable purpura with dusky necrotic center and/or hemorrhagic vesicles.
• Necrotizing fasciitis is classically described as: pain out of proportion, crepitance, hemorrhagic bullae, rapid progression, dirty dishwater discharge, systemic toxicity.
• Necrotizing fasciitis is treated with surgical debridement and broad-spectrum antibiotics (typically Clindamycin).
• Rocky Mountain Spotted Fever starts with a flu-like prodrome, followed by a palpable petechiae starting on the wrists/ankles, spreading centrally.
• Rocky Mountain Spotted Fever rash SPARES the face.
• Pemphigus vulgaris: painful oral erosions and flaccid bullae with POSITIVE Nikolsky sign.
• Bullous pemphigoid: NO oral lesions and tense/firm bullae with NEGATIVE Nikolsky sign.
• PemphiguS = Superficial; PemphigoiD = Deeper.
• Sifting Rocks Scabbed Emma’s PALMS (Secondary syphilis, Rocky Mountain Spotted Fever, Scabies, Erythema Multiforme = palmar lesions).