The term granuloma usually refers to a solid group of inflamed cells. Granulomas are your body’s reaction to a biological, chemical or physical irritant, including some kind of trauma.  Usually granulomas appear as small, localized bumps under the skin. The cells that define a granuloma frequently fuse together to create multinucleated, giant cells.

Causes
A granuloma forms granulomas in response to antigens that resist the first-responder inflammatory cells. Sometimes the cause is a foreign body like a splinter, but granulomas may also appear because of an illness or an allergic reaction.

Types of Granulomas

The two main types of granulomas are:

Granuloma Annulare
Often occurring in otherwise healthy individuals, granuloma annulare presents as raised, reddish or skin-colored bumps that form ring patterns, usually on your hands and feet. Although the bumps look unattractive, granuloma annulare doesn’t normally have other symptoms and it should resolve on its own. Sometimes linked with diabetes or thyroid disorders, granuloma annulares can appear in otherwise healthy individuals.

Pyogenic granuloma
Usually a small red, oozing and bleeding bump, pyogenic granulomas appear as an overgrowth of tissue caused by irritation, physical trauma or hormonal factors. The most common locations for pyogenic granulomas are the head, neck, upper trunk, hands and feet. Although pyogenic granulomas are benign growths, sometimes cancer can mimic these nodules so your physician will likely order a biopsy to be safe. Children, pregnant women, and those taking certain medications have a higher chance of developing a pyogenic granuloma.

Treatment
With granuloma annulare, your doctor may recommend a cortisone cream to help with any itching but no other treatment is needed. A granuloma annulare will disappear anywhere from several months to two years after it develops.

To remove a pyogenic granuloma, the doctor will scrape it off with a curette and lightly cauterize the area to inhibit regrowth. Pyogenic granulomas can also be treated with chemicals such as TCA, podophyllin, phenol or silver nitrate.