How do I know my child has a pinworm infection?

Pinworm diagnosis. Early in the morning, before bathing, look closely at your child's recturm. Pinworms look like tiny white threads, or toilet paper residue. You can do a pinworm tape test and submit to the lab for definitive diagnosis.
Depends . If symptomatic, they will have rental itching. If not, they will be asymptomatic. The test is an inspection of the rectum for pin worms or their eggs.