This urticarial rash occured 1 day after a trip to Disneyland in the Spring. It may take up to 2 weeks to heal. Luckily, it shouldn't scar.

POLYMORPHOUS (POLYMORPHIC) LIGHT ERUPTION

Polymorphous Light Eruption (PMLE) is an idiopathic reaction of the skin to ultraviolet light. The key clinical differential is lupus erythematosus.

• The mean age at disease onset in one study was 25.9 years for females and 28.1 years for males
• Patients are "allergic to the sun." But reaction is delayed, taking several days to develop.
  
• The arms and legs are more commonly affected as face and neck "harden" to the sun's effects.
• PMLE is more common in the summer.
  
• A doctor may rule out lupus with ANA and SS-A, SS-B.
• The rash will resolve on its own in about 2 weeks if excessive sun exposure is avoided.
• Patients may "harden" (have less trouble in the sun) near the end of summer.

Several hours to days after sun exposure, patients may develop papulovesicular, erythematous, lacy, urticarial, papular or plaque-type lesions. The face and neck are not typically affected as these areas, through regular exposure, harden to the sun's effects. Outbreaks occur in the summer and may affect any photoexposed area. Patients who travel to sun-intense areas for brief vacations may be most severely affected. ANA, SS-A, and SS-B should be obtained to exclude lupus erythematosus. Variants include juvenile spring eruption of the ears and springtime and summer eruption of the elbows.

Prognosis

In a long-term followup study (23 years after an initial study) of 94 patients, approximately a quarter no longer had symptoms and about half had milder symptoms. There seemed to be a correlation with autoimmune disease in women, but few patients went on to develop lupus.

Polymorphous light eruption on the dorsal hands.

Polymorphous light eruption on the upper thigh.

RegionalDerm

Homepage | Who is Dr. White? | Privacy Policy | FAQs | Use of Images | Contact Dr. White