A 4-year-old child presents with blood-streaked diarrhea and tenesmus. Proctoscopy reveals edema and pinpoint ulcers in the distal colon, and a whitish worm is seen attached to the mucosa. Stool microscopy shows brown, barrel-shaped eggs with prominent bipolar mucoid plugs. The most likely diagnosis is:

• A Ancylostoma duodenale infection
• B Ascaris lumbricoides infection
• C Enterobius vermicularis infection
• D Trichuris trichiura infection ✓

Explanation

Barrel-shaped or football-shaped eggs with bipolar plugs are pathognomonic for Trichuris trichiura, the whipworm. Heavy infections in young children produce dysentery and can cause rectal prolapse because the anterior end of the worm is threaded through the rectal mucosa. Enterobius eggs are A-shaped and flattened on one side without plugs, Ascaris eggs are mammillated and round to oval, and hookworm eggs are thin-shelled oval eggs with segmented embryos.

Reference: Paniker's Textbook of Medical Parasitology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.