Dermatology - Actinic Prurigo

This guide has been written to provide some information about actinic prurigo. You may have been given this guide because you have been diagnosed with actinic prurigo or because we think this might be the cause of your symptoms.

What is Actinic Prurigo?

Actinic prurigo is a rare skin condition characterized by an abnormal reaction to sunlight. It usually affects skin that has been exposed to the sun, especially on the face, lips, and hands, but it can occur on covered areas of the skin in some instances. Patients tend to get worse symptoms during the summer, but the rash can occur any time throughout the year.

What are the symptoms of Actinic Prurigo?

Symptoms of actinic prurigo can vary from person to person, but they typically include:

• Itchiness
• Red spots or patches which can turn into scabs and lumps - this can last for weeks to months and leave scars in their place
• Flaking and skin thickening may occur
• Lips can become dry and sore, and eyes may become inflamed and red
• The symptoms can appear shortly after sun exposure and may persist for several days to weeks, depending on the individual and the severity of the condition

What causes Actinic Prurigo?

The cause of actinic prurigo is still unclear. Evidence suggests that it may be caused by an immune reaction linked to proteins in the skin being altered by sunlight.

Some studies have shown that people with actinic prurigo are more likely to carry certain types of immune-related genes called HLA (human leucocyte antigens). HLADRB*04:07 is present in
60-70% of people with actinic prurigo in the UK but is rare in the general population. A blood sample can be taken to test for this.

Who gets Actinic Prurigo?

Actinic prurigo usually starts in children but can also develop in adults. It is more common in women than men. It can sometimes run in families. It is more common in people of Native American, Latin American or American Indian descent.

Is Actinic Prurigo serious?

Actinic prurigo can restrict your lifestyle, particularly during summertime and on holidays. It can also cause scarring of affected skin. In some cases, actinic prurigo may resolve spontaneously in early adult life. In others, it remains throughout their lifetime with relapses and outbreaks according to the exposure and weather.

Is Actinic Prurigo infectious?

No, there is no risk of somebody developing the condition from coming into contact with you.

Can Actinic Prurigo increase the risk of skin cancer?

No, there is no risk of developing the skin cancer from this condition.

Can Actinic Prurigo be cured?

There is currently no cure for actinic prurigo, but it can be controlled with treatment (see below). Careful sun avoidance and sunscreens can help prevent it from flaring up.

How will having Actinic Prurigo affect me?

If you have been diagnosed as having actinic prurigo you may have to make changes to your lifestyle which can restrict it to some extent. Steroid creams or ointments can be applied if the rash appears, but prevention is better than cure. 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 (UVB protection) and has high UVA protection. Remember to reapply the sunscreen evenly and often
• Learn how much sunlight your skin can tolerate and keep within that limit
• Make sure you introduce your skin to sunlight gradually in the spring
• Some people may need to apply photoprotective window film to the side windows of their car and home to block out UVA. Some car manufacturers offer UV protective glass as standard or as an optional extra

What about vitamin D?

Importantly, for people to make enough Vitamin D themselves, they need a certain amount of sun exposure. The sun protection measures needed for people with actinic prurigo 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 Actinic Prurigo be treated?

Sunscreens

You can be provided with sunscreens on prescription, and these will help prevent the rash developing. Sunscreen should be applied as thickly and evenly as possible and re-applied often.

Topical creams or ointments

Your doctor may prescribe steroid creams or ointments to put on your skin if the rash appears. Steroid creams can be strong and should only be applied sparingly and while the rash is there. You should stop applying steroid cream when the rash has gone.
Emollients or moisturisers can help to reduce the itch and discomfort.
 
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/

Antihistamines

These tablets may help the itching symptoms.

Thalidomide

Thalidomide is a strong medication that works by trying to change the immune system's response and reducing inflammation in the skin. It has been found to be helpful in some people with actinic prurigo. However, it can have side effects in some people, and needs to be carefully monitored. It may not be suitable for you if you have a risk of blood clots or nerve problems, and it can only be used in women of childbearing age with very careful monitoring.

Methotrexate

Methotrexate is another strong tablet that can affect the immune system response. As with other tablets, you should weigh up the risks and benefits to decide whether it should be used.

Desensitising light therapy or UV treatment

This involves carefully exposing the skin to controlled doses of UV light to build up your skin’s resistance to the effects of sunlight.
This is done in a hospital department and usually involves visiting the hospital three times a week for about 5 weeks in the spring.
 
Your skin is gradually exposed to a little more ultraviolet light every visit. The effects of desensitisation are lost in the winter so you will have to build up your resistance again in the next spring.

Hardening or Toughening

Some people with actinic prurigo 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:

Mrs Smith knows her actinic prurigo 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

Contact us

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