| Polymorphous light eruption | |
|---|---|
| Classification and external resources | |
| ICD-10 | L56.4 |
| ICD-9 | 692.72 |
| DiseasesDB | 10327 |
| eMedicine | derm/342 |
Polymorphous light eruption (PLE), or polymorphic light eruption (PMLE), is a skin condition caused by sunlight.
Contents |
Two subtypes have been described:[1]
Symptoms include skin irritations, which may be itchy or painful, and are sometimes confused with hives. These irritations appear upon exposure to sunlight—sometimes only hours after exposure[2]—and may last from 1 to 7 days.
The cases of this condition are most common between the spring and autumn months in the northern hemisphere.
Typically, 5-20% of fair skinned populations are affected, but it can occur in any skin type.[3] It is more common in females than in males. The condition can affect all ethnic groups and research suggests that 20% of patients have a family history of the complaint. Those suffering from PLE usually do so by age 30.
It has been noted that PMLE is caused by an immune reaction to a compound in the skin which is altered by exposure to ultraviolet light. It can be provoked by UVA or UVB rays.
The cause of PLE is not yet understood. It is thought to be due to a type IV delayed-type hypersensitivity to an allergen produced in the body following sunlight exposure.[3]
One may also purchase clothing that has been tested for its protective qualities.
Some progression to autoimmune disease has been observed.[4]
Generally, PLE resolves without treatment; also, PLE irritations generally leave no scar.