A 54-year-old male with well-controlled human immunodeficiency virus (HIV) presented with fevers and a red nodule on the wrist. Two weeks previous, he was scratched by his cat. His medical history included lymphoplasmacytic lymphoma (LPL) with Waldenstrom macroglobulinemia. A solitary 1.7cm red nodule was present on the right wrist (Figure 1). He was febrile to 103F. A complete blood count showed baseline anemia and thrombocytopenia. The complete metabolic panel was unremarkable. His CD4+ T-cell count was 466 cells/mm3 (reference 410-961 cells/mm3), and his HIV viral load was undetectable. Historically, the patient's CD4 nadir was 274 cells/mm3. The patient underwent shave removal of the visible nodule. Histopathologic examination of the nodule demonstrated diffuse dermal vascular proliferation (Figure 2). Gram, Gomori methenamine silver, acid-fast bacillus, and human herpesvirus-8 stains were negative. There was focal uptake within the dermis with Warthin-Starry stain (Figure 3). Tissue and blood cultures were negative. Polymerase chain reaction (PCR) from the tissue sample was positive for Bartonella henselae DNA, consistent with a diagnosis of bacillary angiomatosis (BA). The patient was started on a 3-month course of doxycycline. At his follow-up appointment one month later, he continued to be afebrile. The biopsy site healed with a circular scar without recurrence.Lisa Ishii (MD, Department of Dermatology, Vanderbilt University Medical Center, Nashville, TN, USA), Alan S. Boyd (MD, Department of Pathology, Vanderbilt University Medical Center, Nashville, TN, USA)Includes bibliographical reference
