Photo Rounds

Anal itching

A mother brought her 4-year-old son to the family physician (FP) for treatment of anal itching. Noting several excoriations around the anus, the FP applied scotch tape to the perianal area and placed the tape on a glass slide. (Slide under the microscope is shown here.)

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The FP detected adult worms and ova of Enterobius vermicularis. Pinworms are acquired through the oral route when hands that have been in contact with contaminated objects are placed in the mouth. This can happen when kids play together in a sand box.

In this case, the young boy was treated with a single dose of chewable 100 mg mebendazole and his symptoms resolved. The parent was told to repeat the mebendazole dose in 2 weeks to increase the long-term cure rate.

If the tape test had been negative, the FP could have chosen to treat empirically, since mebendazole is a safe medication. Another option would have been to have the parent apply the scotch tape to the boy’s perianal area first thing in the morning and bring the tape back to the office. (The yield is higher in the morning.)

Photo courtesy of James L. Fishback, MD. Text for Photo Rounds Friday courtesy of Richard P. Usatine, MD. This case was adapted from: Chumley H. Intestinal worms and parasites. In: Usatine R, Smith M, Mayeaux EJ, et al, eds. The Color Atlas of Family Medicine. New York, NY: McGraw-Hill; 2009:916-920.

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