A rash is a rash is a rash, right? Not quite! The target-shaped spots of erythema multiforme may be unlike any other rash you've ever seen.
Erythema multiforme is a hypersensitive reaction to an infection or medication that causes red, target-shaped or "bulls-eye" patches or sores on the skin. The rash usually starts off looking like pink or red blotches that develop over a few days into round shapes that look like targets (with red, pink, and pale rings). They sometimes have blisters or scabs in the center.
The rash usually starts on the arms, hands, legs, and feet, but you might also find it on the face, neck, and body. Your child may complain that the rash burns or itches. It also can affect the lips and mouth. As the rash goes away, it may turn a brownish color.
The rash, which usually develops quickly, may be the only sign that a child has the condition. However, sometimes kids may also feel tired or have these problems:
- mouth sores or blisters
- low-grade fever
- mild ache in joints and muscles
Causes
Most cases of erythema multiforme are believed to be a reaction to an infection that causes the body's immune system to damage the skin cells. More than half of cases are associated with the herpes simplex virus, the virus that causes cold sores. But bacteria like mycoplasma, fungi, and other viruses are also to blame.
Erythema multiforme also can be triggered by taking certain medications, such as:
- seizure drugs, like phenytoin
- anesthesia drugs, like barbiturates
- nonsteroidal anti-inflammatory drugs, including ibuprofen
- antibacterial drugs, like sulfonamides
- penicillin and other antibiotics
In addition, some cases occur after someone has received an immunization, such as the tetanus-diphtheria-acellular pertussis or hepatitis B vaccines.
The condition is not contagious, so cannot be passed from one person to another.
Diagnosis
A doctor is usually able to recognize erythema multiforme just by looking at it. To help figure out what caused it, the doctor will ask about any recent infections your child may have had and any medications he or she is taking.
Treatment
Erythema multiforme goes away on its own without treatment. In most cases, though, the doctor will try to treat the cause of the rash. For example, the doctor may recommend that your child take an antiviral or antibiotic medicine if an infection is the suspected cause. If the doctor thinks that a medicine may be causing the reaction, your child should stop taking that medicine.
To help make your child feel better, the doctor may recommend:
- putting moist compresses on the rash
- giving your child acetaminophen, antihistamines, or topical creams to help relieve itchiness or soreness
While these treatments provide relief, they do not shorten the duration of the rash.
Outlook
Most kids who get erythema multiforme have no long-term effects. The rash usually goes away in 1 to 2 weeks, but can last as long as 4 weeks. It may also come back again (recur) after it has gone away, especially if your child is re-exposed to whatever caused the initial outbreak (for example, your child may need to avoid certain medicines). If the herpes virus is the cause, the doctor may prescribe a daily antiviral medicine to prevent recurrences.
Reviewed by: Patrice Hyde, MD
Date reviewed: April 2009
