What is the aim of this leaflet?

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

What is capillaritis?

Capillaritis, also known as pigmented purpura, is a skin condition in which red and brown dots and patches appear on the skin. It usually affects the lower legs and does not cause any symptoms. It is more commonly seen in adults though can affect children too.

What does capillaritis look like?

Initially flat, small red and brown dots develop on the skin. Over time these areas may join together to form a larger patch of colour change. Over weeks to months (rarely years) the areas will fade back to the colour of the surrounding skin.

What causes capillaritis?

Capillaritis may develop spontaneously, with no clear trigger. However, occasionally it can be due to a viral illness, intense exercise, venous hypertension (high pressure in the leg veins), allergy (e.g. to black rubber or khaki-clothing dye) and medications (including aspirin, diuretics, thiamine, calcium channel blockers and anti-epileptic drugs).

The underlying process is thought to be that these factors make capillaries (the very small blood vessels in skin) inflamed and therefore leaky. Red blood cells can then leak out into the skin, causing the discolouration seen. When the blood is reabsorbed by the body the red colour turns to a brown colour as a result of breakdown of the red blood cells (haemosiderin deposition).

What are the different types of capillaritis?

There are several different types of capillaritis, these are:

• Schamberg disease (progressive pigmented purpura)

Schamberg is the most common type of capillaritis and tends to occur in young and middle-aged adults. It most commonly affects the lower legs with red-brown dots, described as cayenne pepper spots, seen. It does not usually cause symptoms.

• Itching purpura

This looks the same as Schamberg’s disease though patches may have a scaly surface. It is very itchy. It often starts at the ankles but can spread to affect the whole body.

• Exercise-induced capillaritis

Following prolonged or vigorous exercise, especially during warm weather, areas of red spots may appear around the ankles. A burning sensation may be felt when new spots appear. The spots fade to brown within a few days and eventually disappear.

• Gougerot-Blum (pigmented purpuric lichenoid dermatosis)

This form of capillaritis is less common. The patches tend to be thicker, located on the lower legs and intensely itchy

• Lichen aureus

This is a single golden orange patch (aureus meaning golden), usually seen on the lower legs overlying a varicose vein. These tend to be very persistent. More common in young adults.

• Majocchi purpura (purpura annularis telangiectodes)

Here there are ring-shaped brown and red patches with clear skin centrally, there may be red dots seen at the border. These spread outwards over time. It is more common in females.

• Unilateral linear capillaritis (Linear pigmented purpura)

This form of capillaritis produces a straight line of red-brown patches usually on one lower leg.

Is capillaritis hereditary?

No.

What are the symptoms of capillaritis?

Capillaritis can be itchy, particularly with some of the specific types as listed above. Some people describe a burning sensation of the overlying skin, particularly when new spots develop. Other people have no symptoms at all.

How can capillaritis be diagnosed?

A dermatologist may be able to diagnose the condition just by looking at the skin, however in some cases a biopsy is needed to confirm the diagnosis.

Blood tests may be done to check the full blood count and clotting.

If an allergic cause is suspected, then patch testing may be done (please see the BAD patch testing patient information leaflet).

Can capillaritis be cured?

The natural course of capillaritis is that it will resolve itself over time.

Some people may have one episode and no recurrence, whereas others may have many episodes.

How can capillaritis be treated?

If a medication is suspected as the cause this will be stopped if safe to do so.

Compression stockings can help to prevent leakage of blood from capillaries and so these can be given for capillaritis of the lower legs to reduce recurrence.

Topical steroids will not clear capillaritis, but may be helpful in relieving itching.

Light therapy (PUVA or UVB) may be recommended; some people have recurrence after treatment is completed but others remain clear of the rash.

Where can I get more information about capillaritis?

Web links to detailed leaflets:

http://www.dermnetnz.org/capillaritis

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

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 JULY 2017
UPDATED MAY 2021
REVIEW DATE MAY 2024