Which signs and symptoms are characteristic of pinworms?

Choice A reason: Switching formula does not address projectile vomiting followed by hunger, suggestive of pyloric stenosis, a mechanical obstruction. Changing formula may delay diagnosis and treatment, risking dehydration or malnutrition. Immediate clinical evaluation is needed to confirm the condition and plan surgical intervention, making this response inappropriate.

Choice B reason: Frequent burping reduces air in the stomach but does not address projectile vomiting from pyloric stenosis, caused by pyloric muscle hypertrophy. This symptom requires surgical evaluation, not feeding adjustments. Burping is ineffective, as the obstruction persists, making clinical evaluation the priority to prevent complications.

Choice C reason: Projectile vomiting with hunger in a 2-month-old suggests pyloric stenosis, requiring urgent clinical evaluation for diagnosis via ultrasound and surgical planning (pyloromyotomy). Prompt assessment prevents dehydration, electrolyte imbalances, and growth issues, making this the appropriate response to ensure timely intervention for this serious condition.

Choice D reason: Oral rehydration solution treats dehydration but does not address the underlying cause of projectile vomiting, likely pyloric stenosis. This delays definitive surgical treatment, risking worsening dehydration or malnutrition. Clinical evaluation is critical to confirm the diagnosis, making rehydration a secondary, not primary, response to the symptoms.

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.