Fresh water exposure with maculopapular dermatitis on the lower legs that itches, followed by fever, urticaria, headache, and eosinophilia. Which disease is most likely?

• A. Schistosomiasis
• B. Malaria
• C. Leishmaniasis
• D. Ascariasis

Answer: (A)

This scenario highlights schistosomiasis, caused by cercariae in freshwater penetrating the skin. The initial itchy maculopapular dermatitis at exposure sites (swimmer’s itch) results from the skin penetration by schistosome larvae. Weeks later, the body’s immune response to migrating larvae and eggs produces eosinophilia and systemic symptoms such as fever, urticaria, and headache—classic acute schistosomiasis (Katayama fever). The freshwater exposure with a pruritic skin eruption followed by eosinophilia and fever fits this pattern.

Malaria is vector‑borne (mosquitoes) and usually presents with fever cycles, not dermatitis after freshwater contact. Leishmaniasis involves skin ulcers or systemic illness from sandflies, not a freshwater-associated itchy rash. Ascariasis comes from ingestion of eggs and presents with GI symptoms and pulmonary migration, not a freshwater‑related skin eruption followed by eosinophilia.