Dermatology - Photoaggravated Psoriasis

This guide has been written to help answer some of your questions about photoaggravated psoriasis. You may have been given this guide because you have been diagnosed with photoaggravated psoriasis or because we think this might be the cause of your symptoms.

What is photoaggravated psoriasis?

Psoriasis is a condition that causes scaly, red and sometimes itchy patches to appear on the skin. Photoaggravated psoriasis is psoriasis that is made worse by sunlight. We do not know exactly what causes psoriasis.

What we do know is:

• There is overactivation of the skin’s immune system
• The time normally taken for skin cells to shed from the skin is 3-4 weeks, but in psoriasis this is speeded up with cells being shed after 3-4 days
• If someone else in your family has psoriasis, you are more likely to develop it yourself
• An outside event such as a throat infection, stress or injury to the skin can trigger psoriasis

Who gets photoaggravated psoriasis?

Psoriasis is a common skin disorder affecting 2 in every 100 people. The photoaggravated form of psoriasis is much rarer.

What causes photoaggravated psoriasis?

In photoaggravated psoriasis the skin shows an immune (allergic) response to the ultraviolet radiation in sunlight, which then triggers the psoriasis.

Is photoaggravated psoriasis infectious?

No. There is no risk of other people catching photoaggravated psoriasis from you.

Can photoaggravated psoriasis be cured?

No treatment will completely get rid of photoaggravated psoriasis, but, by careful sun avoidance, use of sunscreens and sometimes certain medications, the rash can often be prevented from flaring. If the rash occurs, it is treated with the standard psoriasis treatments.

How will photoaggravated psoriasis affect me?

If you have been diagnosed as having photoaggravated psoriasis 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?

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 photoaggravated psoriasis mean Vitamin D deficiency is a real risk and this does require treatment with supplements if it occurs. This can be monitored through blood tests.

How can photoaggravated psoriasis be treated?

Sunscreens

Your doctor will provide you with sunscreens on prescription and these will help protect your skin. Sunscreen should be applied as thickly as possible and re-applied as often as possible.

Skin creams

You may be prescribed any of the following:

• Moisturising creams or emollients. Emollients can help to combat the dryness of your skin and can be used as often as necessary
• Topical treatments: these can include creams, ointments, gels, foams and lotions. They may contain corticosteroids, vitamin D based chemicals, vitamin A based chemicals, salicylic acid, tar, dithranol. Further information about this can be found online at https://bad.org.uk/pils/psoriasis-topical-treatments/

Tablets

There are tablets that can be used to treat psoriasis, but they can have side effects. Some examples of these include methotrexate, ciclosporin and acitretin. These options would have to be carefully discussed with your dermatologist to see if they were suitable for you. There are some newer tablet treatments too, but they may not be suitable for everyone.

Injection treatment

Some people with psoriasis are eligible for treatment with medication given by injection. They can cause some side effects, and so as with tablets the risks and benefits need to be carefully considered and discussed with your dermatologist.

More information about tablets and injection treatments for psoriasis can be found online at https://www.bad.org.uk/pils/ psoriasis-treatments-for-moderate-or-severe-psoriasis/

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)
Photobiology.salford@nca.nhs.uk

More information:

Information about psoriasis is also available from the British Association of Dermatologists, at www.bad.org.uk/pils

Links to patient support groups:

The Psoriasis Association
Tel: 01604 251620
Web: www.psoriasis-association.org.uk

Psoriasis and Psoriatic Arthritis Alliance (PAPAA)
Tel: 01923 672837
Web: www.papaa.org

Weblinks to detailed leaflets:
https://dermnetnz.org/topics/psoriasis
https://www.nhs.uk/conditions/psoriasis/symptoms/  
https://patient.info/skin-conditions/psoriasis-leaflet