Kids and OCD

Does anyone have kids that have OCD if so how old and what's their "must do". And how do you handle it? My son is six and he has been washing his hands at least 50 times a day or more. He says they always feel sicky. Told we learned he care wear tank tops. He has had a crazy attitude problem I would say for almost the whole summer but I am not sure if that has to do with the fact that I am pregnant or maybe because this is his first summer being home all summer and it's me and him all day until daddy comes home unless he goes to grandmas. And now when he sleeps over at grandmas he tells her I want my mommy when it's bed time. Any advice will help :)