Polymorphous light eruption
Polymorphous light eruption (PMLE) is a common skin reaction in people who are sensitive to sunlight (ultraviolet light).
Polymorphic light eruption; Photodermatosis; PMLE
Polymorphous light eruption
Polymorphous light eruption (PMLE) is a common skin reaction in people who are sensitive to sunlight (ultraviolet light).
Polymorphic light eruption; Photodermatosis; PMLE; Benign summer light eruption
The exact cause of PMLE is unknown. However, it may be genetic. Doctors think it is a type of delayed allergic reaction. It is common among young women who live in moderate (temperate) climates.
Polymorphous means taking on different forms, and eruption means rash. As the name suggests, symptoms of PMLE are rash-like and are different in different people.
PMLE most often occurs in spring and early summer on areas of the body exposed to the sun.
Symptoms usually appear within 1 to 4 days after exposure to sunlight. They include any of the following:
- Small bumps (papules) or blisters
- Redness or scaling of the skin
- Itching or burning of the affected skin
- Swelling, or even blisters (not often seen)
Exams and Tests
The health care provider will examine your skin. Usually, the provider can diagnose PMLE based on your description of the symptoms.
Tests that may be done include:
- Phototesting, during which your skin is exposed to special ultraviolet light to check if your skin develops a rash
- Removing a small amount of skin for examination skin biopsy to rule out other diseases
Steroid creams or ointments containing vitamin D may be prescribed by your provider. They are used 2 or 3 times a day at the start of the eruption. Steroid or other types of pills may be used for more severe cases.
Phototherapy may also be prescribed. Phototherapy is a medical treatment in which your skin is carefully exposed to ultraviolet light. This may help your skin become used to (sensitized to) the sun.
Many people become less sensitive to sunlight over time.
When to Contact a Medical Profession