Allopurinol-induced arteritis in partial HGPRTase deficiency. Atypical seizure manifestation.

A 17-year-old boy with partial hypoxanthine-guanine phosphoribosyl transferase deficiency developed a hypersensitivity reaction to allopurinol. The reaction was manifested by the development of bizarre, atypical seizures. The patient had been neurologically normal prior to the reaction. Seizures disappeared following discontinuation of allopurinol therapy. Allopurinol apparently can cause a diffuse vasculitis involving cerebral vessels after many year of therapy, resulting in atypical seizures.