A subset of fixed-drug eruption, generalized bullous fixed-drug eruption (which has been defined as blistering on >10% of the body’s surface area at 3 different anatomic sites), may be particularly hard to distinguish from SJS and TEN. Generalized bullous fixed-drug eruption generally has a shorter latency period than SJS or TEN (usually <3 days compared to 7-10 days) and has less mucosal involvement.6
Symptomatic therapy includes antihistamines, glucocorticoid ointment
Management of a disseminated fixed-drug eruption requires a thorough history to identify the causative agent (including over-the-counter drugs, herbals, topicals, and eye drops). Most patients are asymptomatic, but some (like our patient) are symptomatic and experience generalized pruritus, cutaneous burning, and/or pain. Symptomatic therapy includes oral antihistamines and potent topical glucocorticoid ointment for non-eroded lesions. Additionally, if not medically contraindicated, oral steroids may be used for generalized or extremely painful mucosal lesions at a dose of 0.5 mg/kg daily for 3 to 5 days. Be advised, however, that these therapies are based on case report level data.2
Local wound care of eroded lesions includes keeping the site moist with a bland emollient and bandaging. The inciting agent must be added to the patient’s allergy list and avoided in the future. In equivocal cases, it is prudent to admit the patient for observation to ensure that the eruption is not a nascent SJS or TEN eruption.
Our patient was admitted to the observation unit overnight to monitor for the appearance of systemic symptoms and to assess the evolution of the rash for further mucosal involvement that could have indicated SJS. Upon reassessment the next day, his older lesions had evolved into vesiculated and necrotic areas as per the natural history of severe fixed-drug eruption.
He was prescribed prednisone 40 mg/d for 3 days to help with local inflammation, pain, and itching. TMP-SMX was added to his allergy list and he was given local wound care instructions. He was told to return if he developed any systemic symptoms.
CORRESPONDENCE
Jackie Bucher, MD, 7733 Louis Pasteur Drive Apt. 209, San Antonio, TX 78229; bucher@uthscsa.edu.