Polymorphic light eruption (PLE) is a skin condition that results in a rash associated with sun exposure. The appearance of the rash varies significantly (polymorphic literally means many shapes) but skin usually becomes a reddish color and itchy.
PLE can affect anyone of any age, although it most commonly presents in females aged 20-40. Similarly, fair skinned people are more likely to suffer from the condition.
The rash occurs as a result of exposure to sunlight and as little as 20 minutes of sunlight can be sufficient to bring about the effect. Areas of the skin that infrequently experience exposure to sunlight are usually affected to a greater extent. It is for this reason that symptoms are usually worse in spring and summer.
It is unclear why some people are more sensitive to sunlight and suffer from PLE than others. Up to 15% of those with the condition also have family members that are sensitive to sunlight, although there does not appear to be a strong genetic link.
The appearance of the rash can vary widely among individuals that suffer from the condition, although it presents most often as several small red spots occurring together in one area of the skin. The rash may be visible for 1-2 weeks if further sunlight exposure is avoided, however may persist if the individual continues to go in the sun.
It is common for the rash to cause irritation with an itching or burning sensation. Additionally, many people may feel self-conscious about the appearance of the rash, particularly as it occurs in exposed areas and may cause hesitation to participate in activities as usual.
As polymorphic light eruption is directly related to sunlight exposure, it is sensible for people who suffer from the condition to protect their skin from the sun. Way of doing this include:
- Wearing a hat and long-sleeved clothes when intending to partake in outdoor activities in the sun.
- Using sunscreen (at least SPF 30+) to protect skin when in the sun.
- Limit time in the sun between 11am and 3pm when the sunrays are strongest.
It is also possible for skin to acquire resistance to sun exposure. Many people find that gradually building up sun exposure each day allows their skin to become accustomed to the sunlight and avoid the effect of the rash. Ideally, this should be done in spring, spending 5 minutes in the sun each day and gradually building up to as long as individuals need in the sun.
The best method to manage symptoms of polymorphic light eruption is to prevent it occurring by limiting exposure and increasing resistance to sunlight. However, occasionally other treatments are needed to aid the irritation when the rash has already occurred.
Topical corticosteroid creams are most commonly used to soothe the rash caused by PLE. Applied directly to the area, these help to ease burning and itching sensation of the rash and may help to speed the disappearance of the rash.
There is also some concern that people who suffer from PLE do not get enough vitamin D, as they are advised to limit sunlight exposure. For this reason, it is often recommended that people with the condition take vitamin D supplementation.