Drug rashes can appear as a variety of skin
rashes, and may involve the entire skin
surface, or they may be limited to one or a few body parts. Itching is common in many drug rashes. Antihistamine medication may help with the itching.
However, if fever is present, the skin is tender, or the membranes inside the mouth or the genitalia are involved, then a more serious skin condition may be present. Other causes such as eczema or dermatitis, or hives may need to be ruled out.