Bacillary Angiomatosis in an Immunocompetent Patient: An Unusual Occurrence

Dear editor,

Bacillary angiomatosis (BA) is an infectious vascular proliferative disease caused by the gram-negative bacilli of Bartonella species. The occurrence of BA in immunocompetent patients is limited to anecdotal case reports. We report a case of BA in an immunocompetent man and an excellent response to treatment.

A 45-year-old man, a bicycle repair worker, presented with multiple, asymptomatic, red raised lesions with occasional blood-tinged discharge, over both hands of 1-month duration. He denied prior drug intake, exposure to pets, and trauma. However, inadvertent occupation-related trauma could not be ruled out. His physical and systemic examination revealed no abnormality. Cutaneous examination showed multiple (six in number), deeply erythematous, non-tender nodules over the ventral aspect of the right forearm and dorsum of the left hand of 1 to 2.5 cm in size, [Figure 1]; some were with overlying hemorrhagic crust and without regional lymphadenopathy. Hematological and biochemical parameters were normal and serology for HIV-1, HbsAg, and anti-HCV (Hepatitis B and C) was non-reactive. His chest X-ray and abdominal ultrasonography revealed no abnormality. Based on the history and clinical examination, differential diagnoses of BA, Kaposi’s sarcoma (KS), and pyogenic granuloma (PG) were considered. An excision biopsy from the nodule revealed proliferation of capillaries in the dermis with mononuclear inflammatory infiltrate and abundant eosinophils [Figure 2a]. Warthin–Starry-stained sections showed multiple solitary and clustered bacilli in the extracellular matrix around the endothelial cells [Figure 2b]. Thus, the final diagnosis of BA in an immunocompetent patient was made. The patient was prescribed cap. doxycycline (100 mg twice daily) resulting in a dramatic improvement in 2 weeks [Figure 3a], and almost complete resolution at 4 months. Follow-up at 6 months showed no recurrence [Figure 3b].

Figure 1.

Multiple erythematous nodules with hemorrhagic crusts at presentation.

Figure 2.

(a): Section showing an unremarkable epidermis with the presence of a dense inflammatory infiltrate in the upper dermis (hematoxylin and eosin stain × 100). Inset shows the proliferation of capillaries in the dermis (black arrow) with mononuclear inflammatory infiltrate and abundant eosinophils (blue arrow) (hematoxylin and eosin stain × 400). (b): Solitary (red arrow) and clusters of bacilli (yellow arrow) in the extracellular matrix (Warthin–Starry stain × 1000).

Figure 3.

(a): Two weeks post treatment-reduction in size. (b): Six months post treatment-significant improvement.

Bacillary angiomatosis (BA), also known as epithelioid angiomatosis, was first described in 1983 by Stoler et al.[1] as an acquired disease presenting as multiple subcutaneous nodules. The causative organisms are intracellular gram-negative coccobacilli of Bartonella species, namely Bartonella henselae and Bartonella quintana. Domestic cats are the persistent reservoir and transmission occurs through flea vector (Ctenocephalides felis). BA is known to occur in people with immunocompromised states (AIDS, chronic lymphocytic leukemia, corticosteroids therapy, chemotherapy, and following solid organ transplantation). BA has both cutaneous and extra-cutaneous manifestations. The common mimickers include pyogenic granuloma, KS, cherry hemangioma, and verruca vulgaris. Diagnosis is based on clinical as well as histopathological examination. Other diagnostic methods include serological tests (indirect immunofluorescent antibody test), tissue culture, and detection of organisms’ DNA by polymerase chain reaction (PCR). Treatment options for BA include macrolide antibiotics, namely erythromycin, clarithromycin; and tetracycline/doxycycline. Cephalosporin, aminoglycosides, rifampicin, dapsone, and ciprofloxacin have been reported to be effective too. Physical modalities such as cryotherapy, electrodesiccation, and curettage can be used in resistant cases. The occurrence of BA in immunocompetent patients is limited to case reports, a few from India.[2,3] Table 1 summarizes the cases of BA in immunocompetent patients.[4,5,6,7,8,9] There is a slight female predominance (M: F = 4:5) with an age range of 10 to 65 years. The upper extremity is reportedly the commonest site, followed by the face and ankle. This case is being reported for its unusual occurrence in an immunocompetent individual with an excellent response to doxycycline.

Table 1.

Bacillary angiomatosis in immunocompetent patients: a review

Author, country, year	Patient’s age (years) and sex	Site of lesions	Number of lesions	Treatment	Outcome
Cockerell et al., Dallas, 1990[4]	37/Male	Forearm	Multiple	Cotrimoxazole 800 mg × 14 days, erythromycin 500 mg QID PO × 3.5 months and local cryosurgery	Resolved
Karakaş M et al., Turkey, 2000[5]	21/Female	Face	Multiple	Erythromycin 500 mg QID PO × 2 months	Complete resolution
Gangopadhyay et al., India, 2001[2]	65/Male	Forearm	Multiple	Erythromycin 500 mg QID PO × 0.5 months	Resolved
Bernabeu-Wittel J et al., Spain, 2010[6]	59/Female	Ankle	Single	Doxycycline 100 mg BD PO × 2 months	Healed with hyperpigmentation
Zarraga et al., Florida, 2011[7]	10/Female	Chest	Single	Azithromycin 250 mg OD PO × 14 days	Resolved
Iraji F et al., Iran, 2015[8]	26/Female	Arm and fingers	Multiple	Clarithromycin 500 mg BD PO × 3 months	Healed with hyperpigmentation
Nikam et al., India, 2017[3]	45/Female	Arm, forearm, ankle	Multiple	Doxycycline 100 mg BD PO × 4 months	Healed with hyperpigmentation
Balaban et al., Romania, 2019[8]	43/Male	Face	Multiple	Clarithromycin 500mg BD PO × 1.5 months	Resolved
Present case	45/Male	Hands	Multiple	Doxycycline 100 mg BD PO x 4 months	Resolved

OD, once daily; BD, twice daily, QID, four times daily, PO, per oral.

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Conflicts of interest

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