0071643192.pdf

DERMATOLOGY

■ After 1–14 days, abrupt onset of symmetric red macules, which progress to

extensive areas of skin necrosis, usually <10% BSA; may have targetlike

cutaneous lesions

■ Oral mucosa extensively denuded with hemorrhagic crust on lips; may

have compromised airway due to sloughing of respiratory epithelium

■ Involvement of two or more mucosal sites(eyes, mouth, vagina, urethra,

anus)

■ Multisystem involvement may include arthritis, arthralgias, hepatitis,

myocarditis, and nephritis.

CAUSES

■ Majority due to drug reactions (NSAIDs, sulfonamides, anticonvulsants,

antibiotics)

■ Bacterial and fungal infections (rare)

TREATMENT

■ Admit to ICU or burn unit.

■ Identify underlying cause; withdraw offending drug.

■ Skin care, fluid/electrolyte correction

■ Ophthalmology mandatory for patients with eye involvement

■ IVIG and steroids controversial

COMPLICATIONS

■ Mortality up to 10% related to sepsis, GI hemorrhage, fluid/electrolyte

imbalances

■ Long-term morbidity due to scarring, blindness, renal tubular necrosis/RF

TOXIC EPIDERMAL NECROLYSIS

Rare, potentially fatal, adverse cutaneous drug reaction considered by most to

be related to erythema multiforme and Stevens-Johnson syndrome but more

severe; defined by >30% BSAinvolved; affects all age groups and both sexes,

but most common in the elderl; HIV-positive individuals are at a 1000-fold

higher risk for TEN

SYMPTOMS/EXAM

■ 1–3 day prodrome with fever, cough, sore throat, and malaise

■ Abrupt onset of a generalized, dusky, tender, erythematous macules, and

patches that coalesce and slough in large sheets causing widespread, pro-

gressive exfoliation; progression is variable, can be rapid (<24 hours) or

take days

■ Purulent conjunctivitis and painful erosions in the oral and genital skin

■ Positive Nikolsky sign: Tangential pressure results in spontaneous epider-

mal detachment

■ Involvement of the mucous membranes including the GI and respiratory

tract common

CAUSES

■ Drug reactions (penicillin, sulfonamides, fluoroquinolones, anticonvul-

sants, allopurinol, oxicam NSAIDs)

■ Infections

■ Idiopathic

“Target lesion” classically

refers to the bright red

borders and central petechiae

of erythema multiforme and

Stevens-Johnson syndrome,

but is also used to describe

erythema migrans, the

primary lesion in Lyme

disease.

Five dangerous rashes:

Hives associated with

anaphylaxis

Petechiae due to

meningococcemia

Erythema due to TENorSSSS

Macules starting on

wrists/ankles due to RMSF

Woody induration and pain

due to necrotizing fasciitis