I think i might have pin worms, what can happen, i also think its because i suck my thumb.

Pin Worms: cause itching in the anal or vaginal areas etc. Infections occur usually in the very young when the eggs are introduced in the mouth after scratching the itchy areas or touching anything with the eggs. Eggs can lodge in the in the nails. Very infectious so proper hygiene, hand washing, trim nails etc. Household contacts may need to be treated. Medicine is taken once and repeated 2 wks later