Internal Medicine

P1: RLJ/OZN P2: KUF

0521779407-D-01 CUNY1086/Karliner 0 521 77940 7 June 13, 2007 7:41

504 Drug Eruptions

■Intake of prescribed medications, herbal and naturopathic remedies,

over-the-counter products

■Timing of drug intake in relation to rash onset

■Onset varies with reaction pattern (see below) and previous exposure

to the same or a cross-reacting drug. Eruptions following re-exposure

occur more rapidly (minutes for IgE mediated urticaria, hours-2 days

for most other eruptions).

■Past reactions (drugs and topical preparations)

■Conditions increasing risk: HIV/AIDS, chronic lymphocytic leuke-

mia, renal failure, active viral infection (CMV, EBV), collagen vascular

disease, atopy, corticosteroids, and family history of similar reaction

to medications

Signs & Symptoms

■Clinical assessment: MORPHOLOGY, DISTRIBUTION and EXTENT

+/−SYSTEMIC INVOLVEMENT

■Examine: skin including perineum and genitals, mucous mem-

branes (eyes, mouth, pharynx), lymphoreticular system, and any

other symptomatic organ

■MORPHOLOGY

➣Exanthematous– viral exanthem-like, include morbilliform

and maculopapular; spotty erythematous symmetrical eruption,

blanches with pressure, may be minimally palpable or occasion-

ally purpuric, extends over hours – days; onset usually 5–14 days,

range 5 days to 3 months.

➣Urticaria / angioedema– raised pruritic wheals that move every

few hours, produce bizarre shaped lesions (usually intensely

itchy). Onset is minutes in previously sensitized when IgE

mediated (penicillin, sulfonamide antibiotics, cephalosporins)

and anaphylactoid reactions (intravenous radiocontrast media,

vancomycin, narcotics). Onset 1–7 days for aspirin, NSAIDs,

codeine, acetaminophen, and opiate intolerance; and weeks

to months for ACEI-induced angioedema. Serum sickness-like

reaction (urticarial with more fixed lesions that may last days

in the same location plus fever, arthralgia, lymphadenopathy)

7–21 days.

➣Pustular– Acute Generalized Exanthematous Pustulosis (AGEP)

• usually starts groin or head and neck, rapidly evolves to
  widespread erythematous eruption containing numerous ster-
  ile pustules+/−fever and leukocytosis; onset 2–14 days, range
  4 weeks. Acneiform drug eruption – monomorphic acneiform