The itchiness associated with a rash can be treated with hydrocortisone anti-itch creams, oral antihistamines and moisturizing lotions, states MedicineNet. Itchy rashes caused by fungal infections should be treated with topical anti-fungal medications such as Lotrimin or Lamisil.
For mild itchy rashes caused by eczema, insect bites or reactions to allergens such as poison oak or poison sumac, over-the-counter hydrocortisone creams such as Cortaid or Lanacort are recommended by WebMD. These medications should not be used on the face or underarms. The affected area should be washed before the cream is applied, and it should never be covered with a bandage or gauze. Hycrodortisone creams can be applied up to four times per day or as instructed by a doctor.
Oral antihistamine medications that contain diphenhydramine can be used to treat itchy rashes, but they can cause drowsiness, states WebMD. Topical diphenhydramine medications should not be used, as they might make skin irritation worse. Other remedies for itchy rashes include using as little soap as possible when bathing and taking short, cool baths with oatmeal additives. Applying a moisturizing lotion to the skin while it is still damp after bathing helps alleviate dryness, which in turn can reduce itching. Wearing cotton or silk clothing rather than heavy wool is also recommended.