Before commencing treatment for photodermatosis, it is important for your dermatologist to diagnose any predisposing conditions that may be contributing towards the light and sun sensitivity of the skin.

Predisposing Conditions

Sun sensitivity of the skin is present in conditions such as:

Polymorphic Light Eruptions

This is a form of dermatosis of the skin that affects more women than men. Lesions of papules, plaques and vesicles are usually present on the sun exposed areas of the skin. These lesions appear to be more common in the spring and summer seasons and occurs approximately 24 hours after the skin has been exposed to the strong sunlight.

Actinis Reticuloid/Chronic Actinic Dermatitis

This is a rare condition affecting middle aged or elderly men. The area of the skin that is exposed to the sun becomes sensitive to light although the exact cause of this skin disease is not known. Thick plaques of dermatitis begin to develop when exposed to sunlight.

Solar Urticaria and Actinic Prurigo

Solar urticaria, similar to hives, is a rare condition that occurs on the sun exposed areas of the skin. The formation of wheals and skin itching occurs after the skin has been exposed to the sun. Actinic prurigo is a skin condition that begins in the early years of childhood with the development of papules and excoriations on sun exposed areas of the skin.

Treatment & Management

• The individual should wear protective clothing such as a sun hat or a long sleeve shirt on sunny days to protect the skin against sunlight, especially when outdoors.
• Avoid sunlight as far as possible to prevent any further development of lesions.
• Topical preparations of ointments or lotions containing local anaesthetics of benzocaine and other sensitizing preparations should be avoided.
• A course of systemic corticosteroids will decrease any discomfort although this offers only short term relief.
• An oral preparation of hydroxychloroquine reduces and suppresses the skins sensitivity to light.
• Sun block creams or sunscreens should be worn daily on sun exposed areas of the skin and applied many times in a day, especially after swimming.
• PUVA is effective in the treatment of polymorphous light eruptions and should be used on the sun exposed areas of the skin.

With regards to sunscreens, the main preventative agent in photodermatosis, it is important to monitor the sun protection factor (SPF) of your sunscreen. In most cases an application with SPF 15 to 30  may be suitable and higher SPF creams should be avoided as they may cause contact dermatitis. Rather combine your sunscreen with other sun protecting or reducing measures instead of choosing high SPF creams.

Following exposure to sun light, the epidermis increases its production of melanin to provide natural protection against sun exposure. This is seen as darkening of the skin or a tanning effect. Individual skin reacts differently when exposed to the sun making the comparison of light and sun sensitivity differ from person to person as the amount of melanin produced differs in each individual. While this hyperpigmentation may offer some natural protection against the skin, the cause of the light or sun sensitivity should nevertheless be treated.