I have a rash on my wrist and it is very itchy and dry if i leave it , it is kind of bumpy and red, what could it be ?

Dermatitis?: By location, it probably is a contact dermatitis, meaning something irritated it. Usually a topical steroid (like 1% hydrocortisone) or topical Benadryl (diphenhydramine) will help resolve it in a few days. If not, have your dr or a dermatologist look at it.

Dermatitis: Could be do contact with sensitizing agents or chemicals( contact dermatitis) or eczema. See your pcp or dermatologist.