What is Granuloma annulare?
It is a long-term, benign rash that has reddish bumps arranged in a circle or ring on the skin. A granuloma is normally a localized nodular inflammation that closely resembles a grain of sugar or sand. The term “annulare” is derived from the Latin word “anulus”, which means ring.
In 1895, Thomas Colcott Fox was the first person to describe the condition. Henry Radcliffe Crocker in 1902 named the disorder as “granuloma annulare”.
Granuloma annulare Types
The inflammatory condition can be divided into several types based on the clinical features. The five variants of the disorder are given below:
Generalized granuloma annulare
The condition usually affects females between the ages of 50 and 60.
Localized granuloma annulare
In this type, the papules are normally restricted to few areas in the body. It tends to occur in both children and middle-aged adults.
Perforating granuloma annulare
Papular rash with a central keratotic core is the distinctive feature of this particular type of skin ailment.
Subcutaneous granuloma annulare
In this case, the erythematous lesions affect almost twice as many females as males. However, it is likely to occur more in children than adults.
HIV granuloma annulare
This type of disorder is typically marked by papular and generalized bumps on the skin in HIV-affected patients.
Patch-type granuloma annulare
The cutaneous condition, specifically characterized by reddish or red-brown lesions, is commonly seen in women between the ages of 30 and 70.
Granuloma annulare Symptoms
Dermal and annular papules are present in all the types of the disorder. These cutaneous lesions occur in groups and measure about 1-2mm in diameter. The papules normally begin as tiny, pin-sized bumps, but eventually increase in size and spreads to other regions. The annular rash normally has a diameter of 1 cm to 5 cm. Erythema could be an adjunct to this disorder. Frequent sun exposure can cause deterioration of the lesions. The centre of these papules could be depressed and hyperpigmented, or perforated as seen in one of the types. The lateral or dorsal surfaces of the hands, feet and fingers as well as the anterior arms and legs are the commonly affected sites. These are more often clustered around the joints or knuckles. These may occur on the limbs or trunk of patients suffering from generalized granuloma annulare. If present on the elbows, ankles, or groin, the rash may produce pruritic or burning sensation. Interestingly, the overlying skin of patients with subcutaneous papules appears to be normal and difficult to detect. The perforated lesions have, however, a tendency to undergo ulceration in elder patients.
Granuloma annulare Causes
Spontaneous eruption of reddish bumps or rash on the skin without any premonitory signals may have an unknown cause. Medical experts have confirmed the condition as a consequence of an autoimmune reaction that leads to excessive production of white blood cells. However, they are yet to find out the triggering factors involved in over-productive leukocytosis. Few medical investigations haven’t ruled out the possibility of allergic reactions, particularly to copper, tetanus vaccine, and gluten. Apart from this, the dermatological condition could be associated with the following disorders:
- Thyroid disease
- Addison’s disease
- Rheumatoid arthritis
- Systemic lupus erythematosus
Granuloma annulare Pathology/Pathophysiology
Elevated leukocytes in the blood are unable to flow smoothly through the thin capillaries. As these white blood cells clump together and become immovable in the blood vessels, they immediately rise to the surface of the skin and produce annular papules. A group of dermal epithelioid histiocytes around a central zone of mucin is the exact pathological feature of the condition. Medical scientists have also shown the involvement of cell-mediated immunity, immune complex vasculitis, and abnormal monocytes in the pathology of the disease. Primary degeneration of connective tissue in addition to cytokine-mediated degradation may attribute to granulomatous inflammation.
Granuloma annulare Diagnosis
The annular pattern of the papules on the upper and lower extremities suffices for preliminary diagnosis and characterization. Physicians may advice the patients to go for a skin biopsy in order to exclude some well-known skin ailments. Blood test findings are extremely helpful to assess the level of white blood cells. Aside from this result, the CBC count, erythrocyte sedimentation rate, and a rheumatoid factor study may provide further assistance to the doctors. Radiological studies are useful for evaluation of subcutaneous lesions.
Granuloma annulare Differential Diagnosis
Proper diagnosis of the condition generally involves the segregation of a number of skin ailments that are present with similar symptoms. These are:
- Lichen Planus
- Erythema annulare centrifugum
- Erythema elevatum diutinum
Granuloma annulare Treatment
In most cases, the disorder is asymptomatic and does not take more than 2 years to resolve completely in the absence of any therapeutic measures. However, many patients undergo treatment for cosmetic reasons. These may include:
- Steroid creams and ointments
- Oral steroids
- Intralesional corticosteroid injection for localized lesions
- Psoralen + UVA technique
- Fumaric esters
- Potassium iodide
In some cases, natural remedies, such as raw apple juice and cider vinegar, or homeopathic treatments may work better than the conventional therapy.
Granuloma annulare Prognosis
As aforesaid, the dermatological disease is self-limiting and disappears within a few months. It may, however, recur in some patients. Spontaneous remission is possible in subcutaneous granuloma annulare, but the generalized version of the disorder has a poor prognosis. Disseminated cases are more challenging for doctors, and hence require administration of tumor necrosis factor inhibitors.
Granuloma annulare Psychological Factors
As the reddish papules apparently look similar to contagious ringworm (tinea corporis), sufferers may often face cosmetic embarrassment. Such individuals wear different clothing in order to mask the lesions. It is extremely essential for healthcare givers to provide appropriate psychological counseling to these patients. Family members of the patients may discuss their problems with specialists on various online forums.
Granuloma annulare Pictures