What is granuloma annulare?
Granuloma annulare is an uncommon skin condition, which most often affects children and young adults but can occur at any age.
It is twice as common in women as in men. The reason for this is unknown. It usually presents as groups of small firm bumps in the skin which come together to form a characteristic ring-shaped (annular) patch.
These typically occur on only one or two sites of the body, often overlying bony areas such as the back of the hands, the feet, elbows, or ankles.
What causes granuloma annulare?
Granuloma annulare is caused by inflammation in the deep layer of the skin. The reason this reaction occurs is not known.
Granuloma annulare is harmless, does not affect general health, is not infectious or contagious, and is not due to allergies. Some types of granuloma annulare have been linked with diabetes, but this is very uncommon.
Is granuloma annulare hereditary?
No.
What are the symptoms of granuloma annulare?
In most cases, granuloma annulare causes no symptoms, or it may be associated with a mild itch. If knocked, the skin can be tender.
How does granuloma annulare look like?
There are several types of granuloma annulare. The most common is called localized granuloma annulare. This condition is characterized by skin-colored, pink or purple patches, which usually appear on only one or two sites of the body.
The patches can appear anywhere but typically develop on bony areas such as the back of the hands, the feet, elbows, or knees. The involvement of the face is very uncommon.
Usually, the rings start as small in size and then slowly grow to 2.5-5 cm (1 or 2 inches) in diameter. As they enlarge, they become flattened and sometimes more purple in color, and then gradually fade.
Occasionally, people with granuloma annulare can develop a more widespread rash called generalized granuloma annulare, but this occurs in less than 1 in 10 cases.
How will granuloma annulare be diagnosed?
The diagnosis of granuloma annulare is made due to the characteristic appearance of the skin. In some instances, especially in the less common types, a skin biopsy (the removal of a small sample of skin, under a local anesthetic) may be taken and looked at under the microscope in a laboratory to make the diagnosis.
A blood sugar test may also be performed.
Can granuloma annulare be cured?
No, but in over half of the cases it will clear by itself within two years. However, this cannot be predicted accurately on an individual basis.
How can granuloma annulare be treated?
Unfortunately, there is no effective treatment.
Symptomatic or visible patches may improve using steroid creams or ointments. Cryotherapy, which refers to the treatment of skin lesions by freezing them, may be an option for treating tiny patches but can leave a permanent scar.
Evidence for treatments that work in generalized granuloma annulare is limited with no ideal treatment available.
Ultraviolet light treatment and powerful drugs such as steroid tablets, antibiotics, antimalarial drugs, isotretinoin, ciclosporin, and dapsone have been reported to help in individual cases, but, for the vast majority of patients, the symptoms of granuloma annulare do not justify the use of these drugs which all have significant side effects.
Self-care (What can I do?)
There is not a great deal you can do to influence the course of granuloma annulare. There is no current evidence on whether the diet is an influence. Skin camouflage products may help to conceal the affected patches.