How often so pinworms cause itching? been having nocturnal itching a few times in the past month (but only like 2-3 nights & not consecutive).

Almost always: Pinworms like certain warm,dark,moist environments like your rectum at night, itchy skin is. Unavoidable !!

Anal itching: Other diagnosis such as hemoroids, fungal skin infections come to mind for an adult. Pinworms are not usually seen in adults. See a doctor for anoscopy examination by Family Doctor or GI specialist.

Pin worm test: Rectal itch is common and scratching or digging will lead to eggs getting into the fingers. The eggs are then transferred to objects. When eggs are infested will lead another infestation. Highly contagious. Family members or room mates will need treatment. Initially treatment should be repeated in 2 weeks to kill the unhatched eggs that hatched after the first treatment