Anaphylactic reaction to praziquantel following schistosomiasis treatment.

Praziquantel (PZQ) is a medication used to treat several parasitic infections, including human schistosomiasis. Although this drug commonly causes transient adverse effects, severe hypersensitivity is rare, and only eight cases have been reported worldwide. Herein we report a case of a 13-year-old Brazilian female who developed anaphylaxis, a severe hypersensitive reaction, after taking praziquantel to treat Schistosoma mansoni infection. During a mass drug administration event in a socially vulnerable endemic area of Bahia (Brazil), after taking 60 mg/kg of praziquantel the patient developed rash and generalized edema an hour later, evolving to somnolence and hypotension. Following the anaphylactic episode, she received adequate treatment and recovered approximately 1 day later. Although praziquantel is considered safe, health professionals should be aware of potential life-threatening adverse events.