Severe cutaneous adverse drug reactions (SCARs) are serious and potentially life-threatening skin reactions associated with medications used for preventive or therapeutic purposes. This study aims to describe the epidemiological, clinical, evolutionary, and prognostic characteristics of severe allopurinol-induced eruption in the geriatric population.

We conducted a retrospective study including all patients aged 65 years or older between 2005 and 2025 who presented with SCARs and confirmed allopurinol causality based on pharmacovigilance investigations. Among 42 patients with SCARs, 20 cases induced by allopurinol were included.

The mean age was 73.3 years, with a male-to-female ratio of 0.11. The primary indications for allopurinol were gout (55%) and hyperuricemia (15%). The drug-induced skin reaction cases included DRESS syndrome (80%), toxic epidermal necrolysis (10%), and Stevens-Johnson syndrome (10%). The average time to onset was 20 days. The predominant clinical presentation was generalized maculopapular exanthema. Fever and mucosal involvement were observed in 60 and 40% of cases, respectively. Hyper eosinophilia was noted in 15 patients. Management involved discontinuation of allopurinol and initiation of symptomatic treatment. The outcome was mostly favorable, although two deaths were reported.

Allopurinol is one of the most frequently implicated drugs in SCARs, with a higher prevalence in the elderly due to its widespread use in this population. DRESS syndrome is the most common reaction. Although the prognosis is relatively good, it is crucial to avoid allopurinol use in asymptomatic hyperuricemia and to enhance clinical vigilance to prevent these potentially fatal complications. This study highlights the importance of careful drug monitoring and the need for alternative therapeutic strategies in the geriatric population to minimize the risk of severe adverse reactions.