Hi there.. itching on the body may be due to dry skin, skin infection, allergic dermatitis.. find out the reason for allergy like soap, clothes, ornaments.. and avoid the allergen. Avoid mastrubating as it can spread any infection from genitals to other parts of skin since you continuously exposed to the germs in your hand by itching the genitals.. use water based sunscreens, moisturizers, keep yourself well hydrated, antihistamine tablets like cetrizine 10mg will help you by reducing itching, Local steroid creams also used. Consult dermatologist once..