Fixed-drug Eruptions: What can we Learn from a Case Series?

BACKGROUND: A fixed-drug eruption (FDE) is a unique cutaneous adverse drug effect in the form of recurrent lesions at the same site after re-exposure to the offending agent. AIM: The aim of the study was to identify changes in trends in fixed drug eruptions with regard to causative drug or patient risk factors. METHODS: Cases of FDEs encountered between March 2014 to May 2017 during routine pharmacovigilance activities were analyzed. RESULTS: FDEs made up 8.4% of total adverse drug reactions and 11.1% of cutaneous reactions. Majority of the patients were adults between 18 and 45 years old. The average lag period between drug intake and appearance of FDE was 2.04 days. Commonly affected sites were extremities, lips, head and neck, and genitalia. Number of FDE lesions varied from 1 to > 6, with nearly half the patients (46%) presenting with a single lesion. Antimicrobials (80.6%) and nonsteroidal anti-inflammatory drugs (20.8%) were most frequent drugs implicated. Route of administration was oral for all causative drugs. History of an FDE was positive in 26 (50.2%) of the cases. Majority of the patients (21 out of 25 or 84%) whose lesions appeared within minutes to hours of suspected drug intake had a history of FDE. Furthermore, 66.7% of patients with multiple lesions had a history of FDE while only 34.8% of patients with a single lesion had such a history. CONCLUSION: FDEs are common cutaneous reactions with antimicrobials and anti-inflammatory agents, with increased likelihood of extensive and multiple lesions in patients with a history of FDE.