Pinworm (Enterobiasis) Differential Diagnoses

Updated: Mar 07, 2022
  • Author: Sun Huh, MD, PhD; Chief Editor: Michael Stuart Bronze, MD  more...
  • Print

Diagnostic Considerations

The diagnostic process is usually completed after hearing the symptoms of the infected person, including perianal itching, perianal pain,  insomnia, or diarrhea.

Diarrhea can be seen in the early stage of the pinworm infection. Diagnosis is based on the detection of eggs after the perianal swab with cellotape. However, the egg negative finding does not always say the non-infection, because the false negative rate is high. The egg positive finding means that one female worm die after ovulation at the perianal area.  If male worm stay in the caecum, it can not be detected. Also although female worms are present in the large intestine, but do not migrate to the perianal area, egg can not be detected. Therefore more accurate diagnosis, the repeated examination is required. If the worm burden is high, there is a chance of egg positive at the single exam. Howvever, if the worm burden is low, the repeated exam is helpful fo the diagnosis. [1, 2]

Differential Diagnoses