A skin rash is a change in the color and/or texture of the skin on any part of the body. It can have many causes, including allergic reactions, friction, exposure to heat and moisture, infections, fungus, parasites, medications and contact with chemicals or other irritants.

A basic skin rash is known as dermatitis. This term simply means inflammation of the skin. Rashes can be caused by many different factors. In some cases, a patient will come into contact with an irritant or allergen that causes the skin to react. This is known as contact dermatitis, and it can be sparked by substances such as detergents, soaps, fabrics, clothing, rubber, solvents and jewelry.

In other cases, a patient may have an underlying medical condition that causes a rash to form on the skin's surface. Examples include infections, infestation with parasites and diseases such as:

• Fifth disease. Viral disease occurring mainly in early childhood and characterized by fever and a rosy-red rash on the cheeks that often spreads to the trunk and limbs.
  
  
• Hand, foot and mouth disease. A common and highly contagious viral infection that most often occurs in children. The condition is characterized by fever and the development of painful red sores in the throat, mouth and tongue. A rash may also appear on the palms of the hands and the soles of the feet, and may spread to the buttocks. The associated blisters are painful and very contagious.
  
  
• Juvenile arthritis. Chronic arthritis that begins in childhood and is marked by swelling, tenderness, and pain in one or more joints. Fever may also occur, and be accompanied by a rash.
  
  
• Kawasaki disease. An acute disease of young children characterized by a rash, swollen lymph nodes and fever.
  
  
• Lupus erythematosus. A chronic, inflammatory autoimmune disorder that affects the skin, joints, kidneys and other organs. A "butterfly" rash may appear over the cheeks, the bridge of the nose and other areas exposed to sunlight.

In the past, illnesses like chickenpox, measles, roseola and rubella were common causes of skin rashes in children. However, there has been a dramatic drop in the incidence of these diseases since children began to receive vaccinations against them.

Skin rashes usually involve reddened skin that may be inflamed with blisters, bumps or pimples. They are sometimes itchy and may flake, scale, peel or weep fluid. Some may be painful or cause a stinging sensation. In severe cases, the rash may crack or bleed.

Although most rashes will subside without causing any complications, skin rashes can become infected. In addition, severe rashes can result in permanent scarring.