Polymorphic light eruption (PMLE) or in Layman terms – Sun Allergy is a common, sunlight or artificial UVR (Ultraviolet rays) – induced eruption. It occurs within hours to rarely days of exposure, mostly lasting for days to a week or two once exposure ceases.
The most common complaints the patient presents with are, intense itching over the areas exposed directly to sunlight, accompanied with raised reddish or skin colored rashes, sometimes even with blisters. Rarely, the covered parts are affected too. It commonly affects the nose, cheeks, chin, neck, hands, arms, legs and feet. It is more common in young women, often worse in spring and summer.
Treatment mainly comprises of the most important component – Sun protection.
Mild PMLE requires restriction of sun exposure, covering up with appropriate clothing. These days clothing with Ultraviolet Protection Factor (UPF) are also available.
High protection sunscreens with an SPF (Sun Protection Factor) 50 are also advised to all patients.
As simple as sunscreen application seems to appear, many times patients end up applying sunscreen wrongly. The following are few pointers on sun screen application:
- Sunscreen should be applied 15-20 minutes before going out into the sun. This ensures protection to the areas exposed to sunlight.
- A finger tip unit of sunscreen should be applied evenly all over the face, as opposed to taking a pea sized amount.
- Very often patients feel it is not necessary to apply sunscreen when indoors, on the contrary, patients with PMLE have symptoms even when at home and from sunlight streaming in through the windows.
- Sunscreen should be reapplied ever 4-5 hours.
- When buying a sunscreen, look for a sunscreen that has both UVA and UVB blocking agents.
- Sunscreen should be applied daily irrespective of the climate. Only 25 % of UVR is reflected from the sand, while 80% is reflected from the snow.
- Waterproof sunscreen should be applied when going for swimming.
Patients who are severely affected, apart from sun protection, may also require other modalities of treatment like Phototherapy, PUVA therapy etc. which have also been found to be extremely effective.
As much as the sun has its beneficial effects, it also worth noting, that too much of something as simple as sunlight, can also be a harmful thing.
Dr. Anitta Sara Thampi, M.B.B.S, M.D
Bahrain Specialist Hospital