What are the aims of this leaflet?

This leaflet has been written to help you understand more about pityriasis lichenoides. It tells you what it is, what causes it, what can be done about it, and where you can find out more about it.

 What is pityriasis lichenoides?

Pityriasis lichenoides is a rare skin disorder of unknown cause. There are two types of pityriasis lichenoides: an acute (more sudden onset and less persistent) form known as pityriasis lichenoides et varioliformis acuta (PLEVA), and a milder, more persistent form known as pityriasis lichenoides chronica (PLC).

 What causes pityriasis lichenoides?

 The cause of pityriasis lichenoides is not known. It has been reported to occur in the setting of recent bacterial or viral infections and may represent a reaction to infections.

Pityriasis lichenoides most often affects adolescents and young adults and seems to be slightly more common in males of all skin groups.

 Is it hereditary?

No.

What does pityriasis lichenoides look like?

 The acute form (PLEVA): Initially, it has been associated with feeling generally unwell with a fever. The rash starts as flat pink or discoloured spots, which may quickly become more inflamed and/or blister and blood-stained crusting may develop. The spots may come up in crops at different times, so the rash often consists of spots at various stages of development. PLEVA can often be mistaken for chickenpox but it takes much longer to clear than chickenpox. The spots are usually scattered on the trunk, arms, and legs. In children, spots may appear more on the face than at other areas of the body. Scarring and changes in skin colour may occur when the crust falls off.

The chronic form (PLC): The spots look less red or inflamed than in PLEVA and are covered with a firm shiny scale (flake) of skin. The scale can be scraped off by a dermatologist to reveal a shiny, red-brown, or discoloured surface underneath, and may help with confirming the diagnosis. Individual spots flatten within 3 to 4 weeks and the scale becomes loose, often leaving temporary marks which appear darker than the individual’s skin colour. The marks gradually fade away. However, new spots may then appear. Scarring is less likely in PLC than PLEVA. The signs of PLC may be more subtle in more deeply pigmented skin.

What are the symptoms of pityriasis lichenoides?

No symptoms are often experienced in PLC, but in PLEVA, the spots may itch, irritate, or cause a burning sensation as they appear.

How will pityriasis lichenoides be diagnosed?

The appearance of the rash will suggest the diagnosis. However, PLEVA can often look like chickenpox but take much longer to clear than chickenpox, and PLC can look like psoriasis (red, flaky, crusty patch of skin covered with silvery scales). The examination under the microscope of a small sample of the rash (a skin biopsy) taken by a dermatologist can confirm the diagnosis.

Can pityriasis lichenoides be cured?

No treatment is certain to cure the condition. New spots may stop developing after a few weeks, with many cases clear within 6 months. However, the rash may come back and some cases of PLEVA and PLC can wax and wane for several years. The reason for this is currently unknown.

How can pityriasis lichenoides be treated?

• Steroid creams/ointments or tacrolimus ointments may improve symptoms and the healing of spots, but they do not make the rash disappear more quickly.
• Natural sunlight may be helpful and phototherapy with ultraviolet-B, or a combination of tablets known as psoralen + ultraviolet-A (PUVA), may be suggested by your dermatologist to treat the rash. Sometimes PUVA is combined with a tablet called acitretin.
• Reports suggest that antibiotics such as erythromycin or tetracyclines can be given for up to three months and may help some patients.
• Steroid tablets or immunosuppressants such as methotrexate, ciclosporin, or dapsone may be considered for cases that do not respond to other treatment or in very severe cases.

 Self-care (What can I do?)

No treatment is required if the rash is mild and not causing any symptoms, such as itch, but if you are concerned, you may need to seek advice from your doctor.

Where can I find out more about pityriasis lichenoides?

Web links to detailed leaflets:

 https://www.dermnetnz.org/topics/pityriasis-lichenoides

Jargon Buster: https://www.skinhealthinfo.org.uk/support-resources/jargon-buster/

Please note: The British Association of Dermatologists provides links to help people access a range of information about their skin disease. The views expressed in these links may not be those of the BAD or its members.

Please note that the BAD provides web links to additional resources to help people access a range of information about their treatment or skin condition. The views expressed in these external resources may not be shared by the BAD or its members. The BAD has no control of and does not endorse the content of external links.

This leaflet aims to provide accurate information about the subject and is a consensus of the views held by representatives of the British Association of Dermatologists: individual patient circumstances may differ, which might alter both the advice and course of therapy given to you by your doctor.

 This leaflet has been assessed for readability by the British Association of Dermatologists’ Patient Information Lay Review Panel

BRITISH ASSOCIATION OF DERMATOLOGISTS PATIENT INFORMATION LEAFLET

PRODUCED AUGUST 2004

UPDATED MAY 2010, JULY 2013, SEPTEMBER 2016, MAY 2022

REVIEW DATE MAY 2025