Bacillary angiomatosis

Bacillary angiomatosis is an infection that mainly affects the skin but can also involve other organs. It is caused by bacteria from the Bartonella genus, which lead to the growth of abnormal blood vessel clusters. These clusters appear as red or purple bumps or nodules on the skin, which may bleed or become painful. The condition primarily affects people with weakened immune systems, such as those with HIV/AIDS. It can cause symptoms like fever, fatigue, and weight loss if it spreads beyond the skin. Early recognition of these vascular lesions is important for diagnosis. The infection can be serious if untreated but is manageable with appropriate antibiotics.

Bacillary angiomatosis is a vascular proliferative disease caused by infection with Bartonella henselae or Bartonella quintana. It occurs predominantly in immunocompromised patients, especially those with advanced HIV/AIDS, due to impaired cell-mediated immunity. The bacteria induce endothelial cell proliferation, resulting in lobular capillary hemangioma-like lesions in the skin and sometimes visceral organs. Clinically, it presents with erythematous, friable papules or nodules that may ulcerate or bleed. Systemic symptoms such as fever and malaise are common when visceral involvement occurs. Histopathology shows capillary proliferation with neutrophilic inflammation and the presence of bacilli on Warthin-Starry silver stain. The disease is significant because it mimics Kaposi sarcoma and other vascular tumors, requiring specific antimicrobial therapy.