A rash that covers the body could indicate something concerning, such as an infection or allergic reaction. You have a fever with the rash. If this is the case, go to the emergency room. This could be caused by an allergic reaction or an infection. Examples of rashes caused by infection include scarlet fever, measles, mononucleosis, and shingles. Dec 18, · Drug Reactions. Full body rashes may also be caused by a nonallergic side effect of medications 3. For example, corticosteriods can cause an acne-like rash, blood thinners can lead to tiny bruises which may appear as a widespread rash, and some antibiotics cause a rash by making the skin extra sensitive to sunlight.
Sep 27, · Rashes are one of the most common skin problems for adults, children, and babies. Rashes have a variety of causes, including allergies, infections, and certain other diseases.