Polymorphic light eruption is a common rash that occurs in the spring and can affect anyone, but predominantly affects fair-skinned women between the ages of 20 and 40.
Polymorphic light eruption most commonly appears on the arms, chest, legs, and dorsal hands. It is rare on the face. The rash is itchy.
Typically, there are small red papules in the skin, measuring a few millimeters, but it can also present as red patches or vesicular blisters.
The skin usually needs to be exposed to sunlight for a few hours before a reaction occurs. The reaction typically disappears within a few days or weeks and rarely leaves scars.
A few individuals may experience problems throughout the spring and summer. Some may have symptoms persisting for many years, while others gradually improve.
Sunlight reacts with substances in the skin, causing changes that are recognized as foreign by the immune system.
Therefore, this can be referred to as a form of allergy, and the rash can also be called solar urticaria.
Genetic factors play a role. All wavelengths of sunlight can cause the rash.
Preventive measures include the use of sunscreen and limiting sun exposure, which can help the rash resolve more quickly.
Beta-carotene tablets may have a preventive effect.
Topical corticosteroid creams can alleviate the rash, and in severe cases, oral corticosteroid tablets may be taken for a few days.
Corticosteroids reduce itch. Antihistamine tablets can also alleviate itch.
Immunosuppressive treatment with tablets is rarely necessary.
Individuals who experience the rash every year may consider undergoing phototherapy (UVB light therapy). Such treatment should start in the winter to prepare the skin for spring.
