Objective: To report a rare case of new-onset diabetes mellitus following allopurinol hypersensitivity, highlighting the association between drug hypersensitivity reactions and endocrine disorders.
Methods: A 65-year-old male presented with facial edema and cutaneous manifestations following allopurinol treatment for gout. Symptoms persisted despite drug discontinuation. Upon admission, the patient was diagnosed with drug hypersensitivity syndrome and treated with corticosteroids and antihistamines. Metabolic acidosis refractory to bicarbonate therapy necessitated intermittent hemodialysis. Subsequently, the patient developed severe hyperglycemia with diabetic ketoacidosis (DKA) and was diagnosed with type 1 diabetes mellitus.
Results: Immunological studies revealed borderline anti-GAD positivity and seropositivity for HSV, EBV, and CMV, suggesting a possible viral-triggered autoimmune response. The patient responded well to insulin therapy and was discharged in stable condition.
Conclusion: Although rare, new-onset diabetes mellitus following drug hypersensitivity should be considered in clinical practice. In patients with drug-induced hypersensitivity reactions presenting with unexplained metabolic acidosis, DKA should be suspected even in the absence of prior diabetes history. Close monitoring after drug hypersensitivity is essential for the early detection of endocrine complications.