Granuloma annulare

The cause of granuloma annulare (GA) is unknown but many researchers have proposed it may involve an immune and/or inflammatory response. While most cases occur in people who are otherwise healthy, there are a number of triggers and associated diseases. It has been reported to follow insect bites, sun exposure, tuberculin skin tests, tattoos, other injuries to the skin, certain medications (allopurinol, diclofenac, quinidine, calcitonin, amlodipine, ACE inhibitors, daclizumab, and calcium channel blockers), and viral infections (including Epstein-Barr, hepatitis C, herpes zoster, and HIV). GA has been associated with the development of other medical conditions including autoimmune thyroiditis, diabetes, dyslipidemia, and cancer. Chronic stress may be another trigger. However, researchers do not understand why GA only develops in a few people who are exposed to any of these triggers. Although a genetic predisposition to develop GA has been proposed, no specific genetic change (variant) has been found.

Since there are many different triggers and possible associated diseases, as well as different forms of GA, some researchers suggest that there is no single cause of GA, but rather multiple pathways that when triggered can lead to the development of this skin disorder.

For most people, granuloma annulare (GA) goes away within a few years. It tends to last longer if it has spread to more parts of the body (generalized form) than if it is found in just one location (localized form). The generalized form may follow a pattern of spontaneously healing only to develop months or years later. About 25% of cases of generalized GA last for more than five years and for some it may last longer than 10 years.

If granuloma annulare (GA) does not cause bothersome symptoms like itching, then it usually does not need to be treated. If GA does cause symptoms, it can be difficult to find the best treatment, because treatment options for GA have not been studied in large clinical trials. Information about treatment options is available only through published reports from individual cases, a small number of cases, or small uncontrolled studies.

The localized form of GA may be treated with topical steroid creams, topical tacrolimus or pimecrolimus, freezing the lesions (cryotherapy), or laser therapy. Injecting triamcinolone acetonide, a type of steroid, into lesions has also been successful in some cases. In general, steroid creams are usually tried first.

The generalized form of granuloma annulare can be more difficult to treat and many treatment options have been tried. Again, the first treatment is usually topical steroid cream or steroid injections into the lesions. These treatments work best before the lesions are very widespread. Predinsone taken orally (systemic steroid treatment) may also be effective early in the treatment of generalized GA, but the lesions may return when the steroid treatment is stopped. Light therapy, also called phototherapy, is the next main treatment option and involves exposing the skin to ultraviolet light. Light therapy options may include UVA1 phototherapy, PUVA photochemotherapy, or photodynamic therapy.

Other medications that may be given for generalized granuloma annulare include hydroxychloroquine, isotretinoin, or dapsone. Combinations of certain antibiotics (rifampin, ofloxacin, and minocycline) have been shown to be successful in some cases. For people with very severe disease, treatment options may include cyclosporine, infliximab, or adalimumab. In Europe where fumeric ester acids (FEA) have been approved for the treatment of severe psoriasis, FEA has been reported to be effective in treating some cases of generalized GA.

Many of these treatments have shown results in only a few patients and can have side effects. The risks and benefits of each treatment option should be discussed with your doctor.