Which signs and symptoms are characteristic of pinworms?

Choice A reason: Pinworms (Enterobius vermicularis) cause perianal itching due to nocturnal egg-laying, not diarrhea or fever. Diarrhea and fever suggest other infections like bacterial gastroenteritis. Itching is the primary symptom, with irritability from sleep disruption, making this combination less accurate for pinworm infection in children. Choice B reason: Pinworms cause intense perianal itching from egg deposition, leading to irritability and restlessness, especially at night, due to disrupted sleep. These symptoms reflect the parasite’s life cycle, where females lay eggs on the perianal skin, causing discomfort and behavioral changes, making this the most accurate symptom combination. Choice C reason: Nausea and vomiting are not typical of pinworms, which primarily cause perianal irritation. Itching is a hallmark, but nausea and vomiting suggest gastrointestinal infections like rotavirus. This combination is less specific, as pinworms rarely affect the upper digestive tract, making it incorrect for diagnosis. Choice D reason: Nausea, vomiting, and weight loss suggest systemic or gastrointestinal pathology, like inflammatory bowel disease, not pinworms. Pinworms cause localized perianal itching, not malabsorption or systemic symptoms. Itching with irritability is more characteristic, making this combination incorrect for the typical presentation of pinworm infection.