CURRENT Essentials of Critical Care.pdf

268 Current Essentials of Critical CareMorbilliform, Urticarial, & Bullous Drug Reactions■ Essentials of Diagnosis• Onset of rash 5–10 days after exposure to new drug, or 1–2 daysfollowing re-exposure to drug to which a patient has been sensitized;occurs in 25–30% of hospitalized patients• Usually symmetric, widespread, with pruritus and low gradefever; resolution of rash when drug discontinued supports diagnosis• Morbilliform eruptions most common form of drug-inducedrash; usually begins on trunk or dependent areas• Urticaria characterized by pink, edematous, pruritic wheals ofvarying size and shape, usually lasting less than 24 hours• Angioedema represents urticarial involvement of deep dermaland subcutaneous tissues, sometimes involving mucous membranes• Bullous drug eruptions include fixed-drug eruptions, erythemamultiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis,vasculitis, and anticoagulant necrosis■ Differential Diagnosis• Morbilliform eruption: bacterial or rickettsial infection, or collagen-vasculardisease• Non–drug-associated urticarial eruptions: food allergies, insectbites or stings, parasitic infections, and vasculitis or serum-sickness• Bullous drug eruptions: primary bullous dermatoses (bullouspemphigoid, porphyria cutanea tarda)■ Treatment• Identify and discontinue likely causative agents; substitutechemically unrelated alternatives• Morbilliform eruptions: supportive measures, symptomatictreatment (oral antihistamine, topical anti-pruritic agent)• Urticarial eruptions: if severe, aggressive supportive measuresto support blood pressure; epinephrine, fluids, antihistamines,sometimes corticosteroids• Blistering eruptions: decompress large bullae; topical compressesto remove exudates or crusts■ PearlDrug eruptions are most commonly associated with antibiotics, anticonvulsants,and blood products.ReferenceNigen S et al: Drug eruptions: approaching the diagnosis of drug-induced skindiseases. J Drugs Dermatol 2003;2:278. [PMID: 12848112]