Lichen annularis

Lichen annularis is an older term usually used for granuloma annulare. This is a non-contagious skin condition that causes small, firm bumps to form rings or curved shapes. The centre of a ring often looks like normal skin.

The name can be confusing. “Annular” means ring-shaped, while “lichen” is an older term used for several unrelated skin conditions. Lichen annularis is not the same as ring-shaped lichen planus. A dermatologist may use the modern name granuloma annulare to avoid confusion.

The condition involves inflammation in the deeper part of the skin. It is not caused by poor hygiene, and you cannot catch it from another person. It is also not a fungal infection, even though its ring-like appearance can resemble ringworm.

Lichen annularis is usually harmless and does not damage internal organs. Many cases eventually clear without treatment. However, it can last for months or years, return after clearing, or affect a large area of skin. Its appearance or itching can also affect comfort and confidence.

The most common sign is a group of smooth, firm bumps arranged in a ring. The bumps may be skin-coloured, pink, reddish-brown or purple, depending on your natural skin tone.

A ring may start as several separate bumps and slowly become larger. Unlike ringworm, its edge is not usually dry or scaly. Most areas are painless, although some people have mild itching or tenderness.

There are several patterns:

• Localised lichen annularis affects one or a few areas, often the hands, fingers, feet, wrists, elbows or ankles.
• Generalised lichen annularis causes many bumps or patches across the trunk, arms or legs. It may itch more and last longer.
• Subcutaneous lichen annularis causes firm lumps beneath the skin, often on the scalp, hands or lower legs. This pattern is seen mainly in children.
• Perforating lichen annularis can produce bumps with a central dip, crust or small amount of fluid. It may leave marks or scars.
• Patch-type lichen annularis causes flatter red, brown or purple patches rather than clear rings.

The condition does not usually make you feel unwell. Fever, severe pain, widespread blistering or rapidly peeling skin are not typical and need a separate medical assessment.

The exact cause is unknown. The bumps appear when immune cells collect around collagen, a protein that supports the skin. This local inflammatory reaction changes the structure of a small area of skin.

Lichen annularis is not an infection. It is not caused by bacteria, fungi or parasites, and it does not spread through touching, sharing towels or sexual contact.

Individual cases have appeared after minor skin injuries, insect bites, sun exposure, infections, vaccinations or certain medicines. These events may act as triggers in some people, but a clear trigger cannot usually be found. Having a lesion after one of these events does not prove that the event caused it.

Some research has reported links with diabetes, thyroid conditions or abnormal blood fat levels, especially in adults with widespread lesions. Other studies have not found consistent links. Lichen annularis does not mean that you have one of these conditions. Testing is generally based on your wider health, symptoms and medical history rather than the skin appearance alone.

The condition can occur at any age. Localised and under-the-skin forms are often seen in children and younger adults, while widespread forms are more likely to occur in adults.

A healthcare professional can often recognise lichen annularis by examining the shape, colour, texture and location of the bumps. They may ask how quickly the area developed, whether it itches and what treatments you have already tried.

The main conditions that can look similar include ringworm, eczema, lichen planus and other inflammatory skin problems. Ringworm usually has a scaly outer edge and may be checked by gently scraping the skin for fungal testing. Antifungal like fluconazole or terbinafine creams do not treat lichen annularis.

If the appearance is unusual or the diagnosis remains uncertain, a skin biopsy can confirm it. During a biopsy, the area is numbed and a small skin sample is removed. A laboratory examines the tissue under a microscope for the characteristic pattern of inflammation and altered collagen.

Blood tests do not confirm lichen annularis. A clinician may arrange tests for another condition if your symptoms, medical history or examination provide a reason to do so.

Treatment is not always needed. If the area is small, painless and not troubling you, watching it over time may be reasonable. Treatment does not guarantee that the lesions will clear, and they can return later.

When treatment is wanted, the choice depends on the number and location of lesions, their effect on you and the possible side effects.

A corticosteroid cream or ointment may be used to reduce inflammation in a small area. These medicines can thin the skin or change its colour when used too strongly or for too long, so follow the instructions provided with them.

A dermatologist may inject a small amount of corticosteroid like prednisone or hydrocortisone into thicker lesions. This can flatten some bumps but may cause temporary discomfort, thinning or a dip in the treated skin.

Freezing treatment, called cryotherapy, is sometimes considered for a limited number of lesions. It can cause blistering, scarring or lighter or darker marks, particularly in skin that develops pigment changes easily.

Widespread or persistent lichen annularis is harder to treat. Options used by dermatology specialists include light-based treatment, known as phototherapy, and medicines that affect inflammation or the immune system. Evidence for these treatments is limited, and each has its own monitoring needs and possible side effects. Treatment is therefore selected on an individual basis rather than following one approach for everyone.

Moisturisers can help if the skin feels dry, although they do not remove the underlying bumps. Try to avoid scratching itchy areas, since broken skin can become infected or leave longer-lasting marks.

Lichen annularis is not cancerous and does not usually lead to internal illness. The main effects are related to the skin itself.

Possible problems include itching, tenderness and distress about visible lesions. Darker or lighter marks can remain after inflammation settles. These colour changes may take longer to fade than the raised bumps.

Scarring is uncommon in the usual localised form. It is more likely with perforating lesions, repeated scratching or treatments that injure the skin, such as freezing.

Treatment can also have unwanted effects. These may include skin thinning from corticosteroids, pigment changes, irritation or effects from medicines used for widespread disease. Discussing the expected benefit and possible harm can help you decide whether treating a harmless lesion is worthwhile.

There is no proven way to prevent lichen annularis because its cause is unknown. It is not related to poor cleanliness, and changing soaps, washing more often or avoiding contact with other people will not prevent it.

You do not need to isolate affected skin or disinfect clothing and bedding. Other people cannot catch the condition from you.

Avoiding unnecessary injury to an active area may reduce irritation. However, this cannot reliably stop new rings from forming or prevent the condition from returning.

The course is different for each person. Many localised cases flatten and disappear over months or a few years without treatment. Others remain visible for longer or clear and later return in the same place or somewhere else.

Widespread lichen annularis tends to be more persistent than the localised form. Treatment may reduce it without removing every lesion. The condition does not usually follow a steady pattern of getting worse, and skin involvement does not mean that inflammation is spreading through your internal organs.

After a ring flattens, a darker or lighter patch may remain. This is a colour change after inflammation rather than an active lesion. It often fades gradually, although it can persist.

Routine follow-up may be useful if the diagnosis is uncertain, the condition is spreading or you are using a treatment that needs monitoring. A stable, symptom-free area that has been confidently diagnosed may not require regular appointments.

Visible lesions can affect clothing choices, social activities or self-confidence. Camouflage products may reduce the contrast of flat areas, but they will not change raised bumps. If the appearance is having a significant effect on daily life, that is a reasonable reason to discuss treatment.

Arrange a routine appointment if you develop a new ring-shaped rash that has not been diagnosed. Several skin conditions look similar, and ringworm needs different treatment.

You should also seek routine medical advice if the bumps are spreading, itching, painful, repeatedly returning or affecting how you feel about your appearance. Have an area reviewed if it does not behave as expected after diagnosis.

Seek prompt medical care if a lesion becomes hot, increasingly painful or swollen, or starts releasing pus, especially if you also have a fever. These changes can suggest a skin infection rather than uncomplicated lichen annularis.

Lichen annularis itself is not an emergency. Widespread painful blistering, skin peeling, mouth or eye sores, facial swelling or breathing difficulty are not typical. Get urgent or emergency help if these occur, particularly after starting a medicine.

Is lichen annularis the same as ringworm?

No. Ringworm is a fungal infection and often has a red, scaly edge. Lichen annularis is an inflammatory skin condition and usually has smooth, firm bumps. A skin scraping or biopsy can help when the appearance is unclear.

Can I spread it to someone else?

No. It is not contagious and cannot be spread by skin contact, towels, clothing, swimming pools or sexual contact.

Does lichen annularis go away?

It often does, especially when only one or a few areas are affected. Clearing may take months or years, and the condition can return. Widespread forms may last longer.

Should I treat it or leave it alone?

A small, painless area may not need treatment. Treatment may be considered if lesions itch, spread, remain for a long time or cause distress. Available treatments do not work for everyone and can have side effects.

Does lichen annularis mean I have diabetes?

No. Some studies have reported an association, particularly with widespread disease, but the evidence is inconsistent. The skin condition alone does not diagnose diabetes. Testing should be based on your overall health and other risk factors.

Can I use an antifungal cream on it?

Antifungal creams do not treat confirmed lichen annularis. Because ringworm can look similar, it is better to have an uncertain ring-shaped rash assessed rather than repeatedly treating it yourself.