Do pinworms cause an itchy red rash around the anal area?

Yes: Perianal itching is the most common presenting symptom of pinworm infestation & scratching the area can cause redness & irritation. The pinworm is a white, threadlike worm that migrates from the lower bowel where it lives to the perianal area to deposit eggs. Sometimes adult worms may be seen near the anus, particularly in the morning. If you're worried, go see a doc, there are tests & treatment.

Indirectly: The mature pinworm lays it's eggs in the perianal region in a glue like material that most people develop irritation from. The itching/scratching increases the dispersion of eggs.Pinworms are only one of many things that cause perianal itching, so don't assume you have pinworms because you itch there.Food reactions & group A strep like you get for strep throat can cause similar symptoms.