Pyogenic granuloma: pyogenic again? Association between pyogenic granuloma and Bartonella

Pyogenic granulomas (PG) are benign vascular lesions which were thought to have an infectious etiology, yet none has been found. Bacillary angiomatosis (BA), which presents as disseminated vascular lesions in immunosuppressed patients, and verruga peruana (VP), which presents as crops of vascular nodules in immunocompetent persons, are caused by infection with Bartonella. Thus, the question was raised whether Bartonella could be associated with the development of PG, also a vasoproliferative lesion like BA and VP. The objective of this study was to determine through a case-control study whether such an association exists.

Patients who presented with PG and age and sex-matched controls with capillary hemangiomas and senile (cherry) angiomas were tested for serum IgG antibodies against Bartonella using an immunofluorescence antibody method. The prevalence of positive serology was compared between the groups.

Twenty PG patients and 20 control patients with hemangiomas or angiomas were studied. Six out of 20 PG patients tested positive (30%), while none of the 20 control patients tested positive (0%). The difference between the proportions of seropositivity in the two groups reached statistical significance (p = 0.02, df = 1).

Pyogenic granuloma patients were determined to have a statistically higher prevalence of Bartonella seropositivity compared with control patients. Further studies are needed to confirm the association and establish a possible etiological link. Such an association could have potential therapeutic importance. A nonsurgical approach with antibiotics may be possible and may decrease the recurrence rate and occurrence of satellite lesions.