Why am I allergic to the sun?

We feel good in the sun but also know that its ultraviolet light can cause problems with the skin. Sunburn and skin cancer are the most obvious risks but the sun can cause other skin problems and many people can react to the sun after only a few minutes of exposure.
 

We spoke with consultant dermatologist, Professor Andrew Wright, to find out the main causes of skin allergies and treatment options so that you can take care of your skin.
 

What are the main types of sun allergy?

Prickly heat

One of the commonest reactions is often called prickly heat, but this condition is probably better referred to by its proper name of polymorphic light eruption. It is quite a common problem and people affected by this condition develop an itchy, sometimes very lumpy rash, particularly on arms, legs and shoulders.

This usually begins within 12 to 74 hours after sun exposure and can last for several days before settling. It is a condition that can affect anybody, usually from adolescence onwards, and is not necessarily lifelong. It usually occurs when people go away on holiday or particularly in spring when the sun becomes stronger. The condition often improves as the holiday progresses.
 

How can prickly heat be prevented?

Using the correct amount of high factor sun block, 30 to 50, can help to prevent the condition and antihistamines, topical and even oral can also improve the rash.

Having a mild background suntan can help to keep the problem under control which is one of the reasons the condition improves progressively in some people when they are on holiday.

Those severely affected can be given desensitising courses of ultraviolet light under the care of hospital specialists, usually early in the year, which helps to prevent the problem developing.
 

Solar urticaria

Some people react to the sun almost immediately with a sudden red, blotchy, itchy rash which usually only lasts for a few hours and is a form of urticaria.
 

How can solar urticaria be prevented?

This problem can be partially prevented again by the use of high factor sunblocks and antihistamines, but the condition can be difficult to treat and management will require help and advice from a hospital specialist.
 

What can cause sensitivity to the sun?

Medical conditions
There are a number of underlying medical conditions which can cause sensitivity to the sun. These include conditions such as lupus erythematosus and dermatomyositis, conditions which are considered autoimmune diseases. Diagnosis and management of these conditions will again require input from a specialist.

Certain drugs can also cause sunlight reactions. Again, if this is a possibility, your healthcare professional will review your list of medications. Sometimes stopping a particular medicine does not suddenly reduce the sun sensitivity and the support and advice of specialists is important in trying to establish a cause in these circumstances.

Chemicals

Last but not least, there are some chemicals when applied to the skin that can also make it more sensitive to light. These substances are often referred to as photosensitizers and this includes some plants such as giant hogweed, but also some grasses and other plants can cause similar problems. Again, the help and advice of an experienced skin specialist may be needed.
 

If you’re suffering from some of the symptoms mentioned or you’re experiencing other skin issues, you may want to book an appointment with leading dermatologist Professor Andrew Wright. Visit his Top Doctors profile today for more information.