Dermatology - Medicine or diet induced photosensitivity

This patient information leaflet has been written to help answer some of your questions about photosensitivity caused by medication or diet. You have been given this leaflet because we think you may have photosensitivity caused by medication or diet.

What is a medicine or diet induced photosensitivity?

Some medicines can make people become sensitive to light. This is called a medicine induced photosensitivity or sometimes drug induced photosensitivity.

Some foods can also make people sensitive to light. This is called a diet induced photosensitivity.

People with photosensitivity caused by medication or diet develop a rash on skin that is exposed to sunlight. The skin can be very red, or you can develop a dry, bumpy, or blistering rash. The rash can be itchy in some people and not in others. It can be very easy to bring out the rash with sometimes as little as a few minutes exposure to light setting it off. The rash is often there all year round, even on dull days. Some people can even develop the rash from light coming through windows or from artificial lights.

What causes medicine induced photosensitivity?

Some medicines can react with ultraviolet light to cause a reaction in the skin. The doctor will check through all the medicines you are taking to work out which one might be causing the problem.

What causes diet induced photosensitivity?

Some foods and drinks can make people sensitive to light. You would need to be eating or drinking quite a lot of these foods to have a reaction. The doctors will discuss your diet with you if they think your reaction might be caused by your foods or drinks.

How will having a medicine or diet induced photosensitivity affect me?

If you have been diagnosed as having drug or diet induced photosensitivity you may have to make changes to your lifestyle until the drug or diet changes take effect. You should try to:

• Avoid the sun between 11am and 3pm
• Wear protective clothing to stop light reaching your skin. Your clothing should be a close/tightly woven fabric and have long sleeves. Trousers, hats with broad brims, glasses and sunglasses with wrap around lenses can also be helpful
• Consider fitting special ultraviolet blocking film to windows in your house and car
• Use a sunscreen which is SPF 30 or above (high UVB protection) and has high UVA protection. If you are sensitive to visible light you may need a special sunscreen which you can be advised about. Remember to re-apply the sunscreen often

What about other artificial light sources?

Some patients with medicine or diet induced photosensitivity need to be careful around bright artificial light sources.

• Take care with household light bulbs making sure you always keep a good distance (at least 30cm) between yourself and the bulb
• Avoid using single envelope compact fluorescent bulbs in the home; we would recommend switching to LED bulbs
• The ultraviolet lights that some beauticians use when applying artificial fingernails may trigger your rash
• You should not use a sun bed if you have medicine or diet induced photosensitivity

What about vitamin D?

Importantly, in order for people to make enough Vitamin D themselves, they need a certain amount of sun exposure. The sun protection measures needed for people with drug or diet induced photosensitivity mean Vitamin D deficiency is a real risk and this does require treatment with supplements if it occurs.  Your vitamin D levels can be monitored through blood tests.

How can medicine induced photosensitivity be treated?

Most of the medicines that people are prescribed by their doctors have alternatives. We will carefully look through the medicines you are taking and write to your GP recommending which ones she/he could try swapping for another version, if appropriate.

It is very important that you do not stop taking any of your medication before you have checked with your GP.

You have been prescribed the medicines that you are taking because you need them to stay healthy. You should not just stop taking any of them. Your GP will recommend alternatives and then keep an eye on how you are on any new medicine.

Once your GP has given you a different version of the tablets that were making you sensitive to light it can take about 6 months for the effects of all the old medicine to completely leave your body. This means you might still be light sensitive for several months after stopping the tablets.

We may offer you a repeat appointment after 6 months where we sometimes repeat the specialist phototesting to check that your reaction to light has returned to normal.

How can diet induced photosensitivity be treated?

If we suspect that your diet has included a lot of a particular food that might make you light sensitive we will recommend that you stop or reduce the amount of that food that you eat. It may take up to 6 months for the effects of the food or drink to leave your body.

We may offer you a repeat appointment after 6 months where we sometimes repeat the specialist phototesting to check that your reaction to light has returned to normal.

Contact us

The Photobiology Unit can be contacted on 0161 206 4081 or by email Photobiology.Salford@nca.nhs.uk