Annulare and Pyogenic Granuloma

Updated: Mar 26, 2019
  • Author: Richard Lichenstein, MD; Chief Editor: Steven C Dronen, MD, FAAEM  more...
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Granuloma annulare is a benign self-limited dermatosis characterized by a raised annular configuration. See the image below.

Granuloma annulare. Courtesy of Wikimedia Commons Granuloma annulare. Courtesy of Wikimedia Commons (Mierlo at English Wikipedia).

Pyogenic granuloma is misnamed, being neither pyogenic nor granuloma. It is a benign, acquired, vascular tumor of the skin and mucous membrane that appears as a rapidly growing vascular papule or nodule. Sometimes it appears at the site of a previous penetrating injury. Pyogenic granuloma is often observed in infancy and childhood but also may be observed in adults, particularly in pregnant women. See the image below.

Pyogenic granulomas are usually solitary lesions. Pyogenic granulomas are usually solitary lesions. The fingers and hands are common locations for these to develop. A history of minor trauma at the site shortly before development of the lesion is frequent.


Granuloma annulare may be localized, generalized, perforating, or subcutaneous. Lesions of the first 3 presentations have similar appearances, but each one follows a distinctive clinical course. Subcutaneous granuloma annulare appears differently, as it is a disease of childhood in which deep dermal or subcutaneous nodules lie on or near the periosteum and are distributed on the feet, lower legs, fingers, hands, forearms, scalp, and forehead.

Pyogenic granuloma is a disorder of angiogenesis whose underlying etiology remains unknown. A predilection exists for the head and neck, although lesions may appear on any part of the body. Purplish, pulpy, vascular lesions of pyogenic granuloma often involve the gum and other mucous membranes of the mouth. [1]



Granuloma annulare

Etiology of childhood granuloma annulare is unknown.

No good evidence supports suggestions that trauma, tuberculosis, streptococcal infection, herpes zoster/varicella, collagen vascular disorder, or diabetes mellitus are causally related to granuloma annulare. Recently, the first case report of granuloma annulare and diabetes mellitus has been described. [2] There are also weak associations with BCG vaccination; drugs such as allopurinol and zalcitabine; other viral infections such as EBV, HIV, hepatitis C, Parvovirus B19; autoimmune thyroiditis; and malignant conditions. Borrelia has also recently been implicated in one study. [3]

There is some evidence to suggest that granuloma annulare is an immunologic disease in the form of delayed type hypersensitivity reaction.

Pyogenic granuloma

The cause of pyogenic granuloma is unknown.

Suggested potential risk factors include pregnancy, birth control pills, bacterial and viral infections, microscopic arteriovenous anastomoses, and angiogenic growth factors, but no good evidence supports any of these as primary causative factors. In one large pediatric series, only 7% had any history of trauma preceding the development of the lesion.

Pyogenic granulomas have been reported arising within port wine stains. On rare occasions, lesions have been associated with malignancy.

Intraoral lesions can have an appearance and behavior very similar to the appearance and behavior of intraoral Kaposi sarcoma. These lesions may bleed extensively if biopsied; thus, HIV testing may be indicated when patients have intraoral lesions with the appearance of pyogenic granuloma. [4]

Pyogenic granuloma in pregnancy  [5]

Pyogenic granuloma is common in pregnancy, with intraoral mucosal lesions appearing in 5% of pregnancies and in some unknown fraction of patients taking oral contraceptives.

Although the tumor mass often regresses after delivery or in response to adjustment of the contraceptive medication, spontaneous recurrences may be observed.

Etiology in pregnant women may be related to gingival inflammation, as the prevalence is reported to be less in patients with better oral hygiene.




United States

Granuloma annulare is most common in children and young adults.

Solitary pyogenic granuloma is common and represents 0.5% of all skin nodules in children.


Pyogenic granuloma was 50% of reactive lesions compared to 21-26% reactive lesions in a local South Indian population between 1989-2009. [6]


Granuloma annulare is believed to affect patients without respect to racial heritage.

Pyogenic granuloma may affect white populations more than other racial groups, but this is not well proven and the observation may reflect sampling bias.


Granuloma annulare has a slight tendency toward females. In granuloma annulare, females are slightly more affected than males.

In pyogenic granuloma, the male-to-female ratio is 3:2.


More than two thirds of patients with granuloma annulare experience disease onset when younger than 30 years. In pediatric patients with granuloma annulare, the age of onset ranges from 1-14 years, with a mean of 4 years. The localized type of granuloma annulare occurs primarily in young children, whereas the generalized form is seen in patients younger than 10 years or older than 40 years.

Approximately one half of cases of pyogenic granuloma occur within the first 5 years of life.



Granuloma annulare

The prognosis of granuloma annulare is excellent, as the lesions usually regress spontaneously. Fifty to 70% with the localized type resolve after 1-2 years. The generalized type is less likely to resolve spontaneously. Granuloma annulare is a self-limited cosmetic disease without any systemic medical complications. On rare occasions, it may involve fascia and tendons and may cause sclerosis, lymphedema, and deformities such as joint ankylosis. Granuloma annulare has been epidemiologically linked to diabetes mellitus, necrobiosis lipoidica diabeticorum, and rheumatoid nodules.

Pyogenic granuloma

The prognosis of pyogenic granuloma is also excellent. Pyogenic granuloma is a benign vascular tumor, mostly occurring in childhood. Lesions may bleed and ulcerate.


Patient Education

Reassurance and referral are the principal and essential steps in patient education.