Erosive cheilitis as an early manifestation in DRESS syndrome

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a distinct part of severe cutaneous adverse reactions (SCARs). It is characterized by fever, rash, hematologic abnormalities, lymphadenopathy, or/and different degrees of visceral organ involvement. Its diagnosis is particularly challenging due to the variability of its clinical presentations and its long latency period (2–6 weeks). Allopurinol, an uric acid‐lowering drug, has been incriminated in several cases of allopurinol‐induced DRESS syndrome. Through this paper, we present a case of allopurinol‐induced DRESS syndrome with initial oral mucosal involvement. A 69‐year‐old female patient presented with an erosive cheilitis that started 1 week prior to his presentation. The cheilitis was associated with maculopapular rash and fever. She started taking allopurinol, as treatment of Gout, 6 weeks before hospitalization. The histologic findings obtained from skin biopsy were consistent with a toxic drug reaction. A complete blood count (CBC) showed a moderate eosinophilia. Alteration of renal function was also noted, and the diagnosis of allopurinol‐induced DRESS syndrome was made. Systemic corticosteroid therapy was therefore started. The patient completely recovered and had been healthy for 3 years before developing a recurrence after re‐challenge with allopurinol.