Dermatology - Photosensitivity

What is photosensitivity?

Skin light sensitivity (photosensitivity) means you have an unusual reaction to the ultraviolet and/or visible parts of daylight. Photosensitive patients can be extremely sensitive to light which can cause pain, redness, itching or a rash. There are many different types of photosensitivity disorders, but they are all triggered by exposure to daylight. Some are very common, and others are rarer.

What are the symptoms?

Photosensitivity means that you get symptoms when the skin is exposed to daylight. Some common symptoms include:

• Skin rash
• Skin pain
• Itching
• A burning or heat sensation on the skin
• Blistering or fragile skin
• Sunburn that happens very easily

These symptoms can range from mild to severe. Sometimes people may also feel generally unwell due to a light sensitivity disease. For example, you may get headaches or fatigue.  Although it’s rarer, some people may have unusual freckling or scarring of the skin.

When and where am I likely to get the rash?

Some photosensitivity rashes may only occur on exposed sites during summer. However, a rash that’s caused by light sensitivity can also happen in some people all year round, through light clothing, through windows and from some types of indoor light.

You may also notice that the rash stops where you have been covered by clothing or footwear.

Why haven’t you told me which photosensitivity disorder it is?

Our testing and the details you have told us have proved you are unusually sensitive to light. We know that this shows you have a photosensitivity condition but now we don’t have enough information to provide more detail. We may ask you to return when you have your rash so we can see it, or we may take a small piece of skin (biopsy) to see if that helps us to tell which photosensitivity condition it is. Some patients don’t fit into the pattern of any particular photosensitivity disorder and will simply be diagnosed as “photosensitive.”

Who develops photosensitivity?

Anyone can develop photosensitivity. It can start in childhood, adulthood or in older age. Photosensitivity is more common in women than men. It can affect all skin types.

Is photosensitivity serious?

Photosensitivity can restrict your lifestyle quite a lot particularly during the summer months and on holidays. Once the symptoms develop patients need to cover up, stay out of the sun and wait for it to settle. There may be some treatments that can also help (see below).

Does photosensitivity increase your risk of cancer?

No. Experts do not think having photosensitivity increases your risk of cancer. An exception is certain very rare conditions where increased risk of cancer occurs alongside photosensitivity. If this is the case we will specifically inform you.

Is photosensitivity infectious?

No there is no risk of other people catching the condition from you.

Can photosensitivity be cured?

Occasionally a cause can be found such that eliminating it cures the problem. However, in most cases no treatment will completely cure photosensitivity, but it can be controlled. Careful sun avoidance and use of sunscreens can help reduce or prevent the symptoms.

How will having photosensitivity affect me?

If you have been diagnosed as having photosensitivity you may have to make changes to your lifestyle. You should try to:

• Avoid the sun during conditions that provoke your photosensitivity and particularly when sunlight is intense. In the UK this is mainly between 11 and 3pm, although other times of day can be troublesome
• Wear protective clothing, with close/tightly woven fabrics, long sleeves and trousers, hats with broad brims. Glasses and sunglasses with wrap around lenses can also be helpful
• Use a sunscreen that is SPF 30 or above (high UVB protection) and also has high UVA protection. Remember to re-apply the sunscreen evenly and often

What about vitamin D?

Vitamin D is acquired both through sunlight (usually the major source) and diet. In order for people to make enough vitamin D themselves, a certain amount of sun exposure is needed. The sun protection measures needed for people with photosensitivity conditions means vitamin D deficiency is a real risk. Therefore, most photosensitive patients visiting our unit will require regular vitamin D supplement. This can be prescribed by your GP or purchased. It can be monitored through blood tests.

How can photosensitivity be treated?

Sunscreens

Your doctor will provide you with sunscreens on prescription and these will help protect your skin. Sunscreen should be applied quite thickly and evenly and re-applied as often as possible. You will be given a demonstration of how to do this during your investigation at the photobiology unit.

Skin creams

Your doctor may prescribe corticosteroid creams or ointments to put on your skin. Steroid creams can be strong and should only be applied as instructed by your doctor but when used carefully they can control the inflammation and help to ease the itch and tightness of your skin. If you have a severe flare up of your rash you may be advised to use a strong steroid initially for a short period of time and then as the rash improves, you may be instructed to use a lower strength one where appropriate. Lower strength steroid creams are often also used on the face. More information about steroid creams and how they should be used can be accessed through the British Association of Dermatologists website at https://www.bad.org.uk/pils/topical-corticosteroids/ and through the National Eczema Society website.

Tablets

There are some medications that may be able to help if your photosensitivity is difficult to control or if you have a very bad flare up. These tablets can have side effects so you and your dermatologist should weigh up the benefits against the side effects to decide whether they should be prescribed.

Desensitisation or UV Treatment

Occasionally the resistance of your skin to the effects of the sun can be increased by ultraviolet exposure. This is done in a hospital department and will involve visiting the hospital three times a week for about 5 weeks in the spring. It involves gradually exposing your skin to a little more ultraviolet light every visit to try to build up your skin’s resistance. The effects of desensitisation are lost in the winter so you will have to build up your resistance again in the following spring.

Hardening or Toughening

Occasionally people with photosensitivity may be able to increase the resistance of their skin at home. This involves going outside for short periods in the spring to build up your resistance. You might find the time is as short as a few minutes at first, but you may be able to gradually build this up to longer times. You will have to be careful not to overdo it, but as you understand more about how much light triggers your rash you will be able to judge how long to stay out. The effects of hardening are lost in the winter so you will have to build up your resistance again in the spring. We have included an example of how you might try to toughen your skin in the spring.

Example of a self-toughening regime:

Mrs Smith knows her rash usually appears in the evening if she has been out in the sun during the day. Mrs Smith has been toughening her skin in the spring and this is her diary.

Monday - I sat outside in the sun for 5 minutes. I went back indoors and waited until the evening to see if my rash appeared…..thankfully it didn’t.

Wednesday - Today I sat out in the sun for 10 minutes. I covered myself up after that, so I didn’t catch any extra sun and waited until the evening. My rash still didn’t appear.

Friday - I decided to sit outside for 20 minutes, and then I went back inside. This evening my rash started and I felt itchy. I put some steroid cream on thinly and stayed out of the sun.

Sunday - The rash has started to go down, but it still hasn’t fully gone. I will wait until next Wednesday before I go back out into the sun.

Wednesday and for the next week (daily or alternate days) - I sat out in the sun for 10 minutes. The rash did not come back.

The following Wednesday - Sat out in the sun for 20 minutes….no rash! Will now continue to sit out in the sun for 20 minutes, daily or alternate days, for the next week. After that I’m going to try to increase to 30 minutes.

Contact us:

If you need any further advice we will do our best to help. Contact us at the Photobiology Unit on 0161 206 4081 (9am - 3pm) or email Photobiology.salford@nca.nhs.uk