|Classification and external resources|
Generalized Granuloma Annulare on hand
Granuloma annulare is a fairly rare, chronic dermatological autoimmune condition which presents as reddish bumps on the skin arranged in a circle or ring. The rings are caused by an autoimmune reaction that causes over-productive leukocytosis, an over abundant production of white blood cells. These WBCs do not flow freely through the blood but instead clump together and can not effectively move through thin capillaries, rising to just underneath the surface of the patient's skin, resulting in the characteristic rings. It can initially occur at any age and is significantly more common in females (80/20 ratio).
Granuloma annulare may be divided into the following types::703–5
The condition is usually seen in otherwise healthy people. Occasionally, it may be associated with diabetes or thyroid disease. It has also been associated with auto-immune diseases such as systemic lupus erythematosus, rheumatoid arthritis, and Addison's disease. The cause of the autoimmune reaction which cause the WBC production is currently unknown. Some theories include possible allergic reactions to wheat gluten, copper, or tetanus vaccine, among others, to a result of having had a broken bone. At this time no conclusive connection has been made between patients.
Aside from the visible rash, granuloma annulare is usually asymptomatic. Sometimes the rash may burn or itch. Patients usually notice a ring of small, firm bumps (papules) over the backs of the forearms, hands or feet, often centered on joints or knuckles. The bumps are caused by the clustering of T cells below the skin. These papules start as very small, pimple looking bumps, which spread over time from that size to dime, quarter, half-dollar size and beyond. Occasionally, multiple rings may join into one. Rarely, granuloma annulare may appear as a firm nodule under the skin of the arms or legs. It also occurs on the sides and circumferential at the waist and without therapy can continue to be present for many years. Outbreaks continue to develop at the edges of the aging rings.
Granuloma annulare, microscopically, consists of dermal epithelioid histiocytes around a central zone of mucin - a so-called palisaded granuloma. The main histomorphologic differential diagnosis in necrobiosis lipoidica/necrobiosis lipoidica diabeticorum, which typically has plasma cells.
In simple terms, it is a group of white blood cells that clump together and rise to the surface of the skin.
Prognosis and treatment
Because granuloma annulare is usually asymptomatic and self-limiting with a course of about 2 years, treatment is not necessary except for cosmetic reasons. Initial treatment is generally topical steroid creams, followed by oral steroids and finally intradermal injections at the site of each ring. Treatment success varies widely, with most patients finding only brief success with the above mentioned treatments. New research out of India suggests that the combination of rifampin (600 mg), ofloxacin (400 mg), and minocycline hydrochloride (100 mg) once monthly, or ROM therapy, produces promising results. Most lesions of granuloma annulare disappear in pre-pubertal patients with no treatment within two years while older patients (50+) have rings for upwards of 20 years. The appearance of new rings years later is not uncommon.
GA patients can face considerable stigma attached to their condition because papules superficially resemble ringworm, a slightly contagious itching skin disease occurring in small circular patches, with scaling (unlike granuloma annulare) caused by any of a number of fungi. Granuloma Annulare, in some cases, can look like a rampant, unchecked case of ringworm and can draw frequent stares and comments. For just this reason, many patients prefer to wear long-sleeved shirts and pants, even fingerless gloves, regardless of the outside temperature, in an effort to camouflage their condition. In addition, papules can be mistaken for cigarette burns or even human bite marks, depending on their size.
- James, William D.; Berger, Timothy G.; et al. (2006). Andrews' Diseases of the Skin: clinical Dermatology. Saunders Elsevier. ISBN 0-7216-2921-0.
- "Granuloma annulare: Causes - MayoClinic.com".
- "Granuloma Annulare: Treatment & Medication - March 14, 2007".
- Shanmuga1, Sekar C.; Rai1, Reena; Laila1, A.; Shanthakumari, S.; Sandhya, V. (2010), "Generalized granuloma annulare with tuberculoid granulomas: A rare histopathological variant", Indian Journal of Dermatology, Venereology and Leprology 76 (1): 73–75, doi:10.4103/0378-6323.58691, retrieved 23 May 2010