what is causing my rash
A rash is a noticeable change in the texture or color of the skin. The skin may become itchy, bumpy, chapped, scaly, or otherwise irritated. Rashes are caused by a wide range of conditions, including allergies, medication, cosmetics, and various diseases. The rash is often reddish and itchy, with a scaly texture. 2  bug bites: tick bites are of particular concern, as they can transmit disease. 3  psoriasis: a scaly, itchy, red rash that forms along the scalp and joints. 4  dandruff: an itchy, flaky rash on the scalp.