Master Pinworm (Enterobius Vermicularis) with Picmonic for Medicine

Pinworm is a nematode, or roundworm, and is one of the most common parasitic infections in the world.

Infection occurs through the ingestion of the eggs from pinworm. This typically involves fecal-oral transmission through contaminated hands, foods, or sometimes water.

After ingestion of the eggs, a 4-6 week incubation ensues and patients develop intestinal infection of adult pinworms. This infection is called enterobiasis and is asymptomatic in 1/3 of individuals.

The most common symptom of enterobiasis is intense anal pruritis; this occurs because the adult pinworms exit the digestive system to lay eggs around the infected host's anus at night. This pruritus can be seen around the perineum and anus, and can be described as tickling, tingling or even painful.

Diagnosis of pinworm infection is done via the scotch tape test, where transparent adhesive tape is applied to the patient's anal area. This tape is then removed and viewed under low-power microscope to look for pinworm eggs.

The primary treatment for pinworm is albendazole, which works to inhibit glycogen metabolism in worms, starving them to death. This drug only kills adult worms, and must be re-administered (after eggs hatch and mature) to fully eradicate infection. Mebendazole, another bendazole drug, may also be used in the treatment of pinworm.

Pyrantel pamoate is used as a second-line treatment against pinworm, and works by causing neuromuscular blockade in the parasite.