Drug-Induced Parotitis—A Rarity?

Unilateral parotitis is due to ductal obstruction. Bilateral parotitis occurs due to viral infections such as mumps, bacterial infections, Sjögren syndrome, and ductal obstruction. Drug-induced parotitis is a relatively uncommon adverse reaction, and it can be unilateral and bilateral. Unilateral causes of drug-induced parotitis can be due to clozapine, chlorpromazine, l-asparaginase, and α-methyldopa, whereas bilateral causes can be due to thioridazine, sulfadiazine, phenylbutazone, oxyphenylbutazone, nitrofurantoin, and valproic acid. Adverse reactions to sulfonamide are rare and manifest as rashes or urticaria. Herein, we report a case of acute unilateral parotitis occurring as a result of cotrimoxazole that resolved within 48 hours after discontinuation of therapy, which highlights that sulfonamide therapy can cause parotitis. Early clinical suspicion and discontinuation of therapy help in the prompt resolution of the allergic reaction to cotrimoxazole.