Common skin rashes include seborrheic dermatitis, eczema and poison ivy, according to MedicineNet. Seborrheic dermatitis, the most common adult rash, typically appears as a red, scaly rash on the scalp, forehead, outer ears, cheeks and eyebrows. Eczema frequently appears in children and in hay fever and asthma patients.
Known as atopic dermatitis, eczema is a weeping, itchy, red rash that often develops behind the knees, inside the elbows and on the wrists, ankles and cheeks, notes MedicineNet. Poison ivy is a type of contact dermatitis, a rash that occurs after the skin makes contact with a particular irritant or with a chemical to which an individual is allergic. The parts of the skin that touch the irritant or chemical develop the oozy, weepy rash.