| Epidemiology | • Bartonella henselae/quintana (G- bacillus) • Cat exposure (henselae) or homelessness (lice) (quintana) • Severe immunocompromise ◦ Advanced HIV (CD4 <100/mm3) | | --- | --- | | Manifestations | • Vascular cutaneous lesions (papular, nodular, peduncular) • Systemic symptoms (fever, night sweats, fatigue) • Organ involvement rarely (liver, bone, CNS) | | Diagnosis | • Lesional biopsy with microscopy/histopathology showing bartonella | | Treatment | • Doxycycline or erythromycin • Antiretroviral therapy (usually 2-4 weeks later) |
Symptoms feature vascular cutaneous lesions that often begin as small reddish/purple papules and evolve into friable pedunculated or nodular lesions.
The diagnosis is confirmed if a biopsy of the affected tissue shows vascular proliferation and neutrophilic infiltrate and positivity on Warthin-Starry staining. T
The organism causes a local dermal infection, spreads to the vascular endothelium, and then attacks red blood cells. The major manifestations of infection are therefore mostly cutaneous, lymphatic, and endovascular (Cat-scratch disease, bacillary angiomatosis, endocarditis).
Bright red, firm, friable, exophytic nodules
(Choice A) Bacillary angiomatosis and Kaposi sarcoma may be difficult to distinguish. However, the skin lesions of Kaposi sarcoma also occur on the trunk and extremities. Typically, the lesions are papules that become plaques or nodules; the color changes from light brown, to pink, to dark violet. Bacillary angiomatosis is more likely given this patient's firm, exophytic nodules and fever.