Abstract
38-year-old male with a history of aortic valve repair, presented with fever, and chronic, asymptomatic, migratory rash on the posterior neck and extremities. Patient denies photosensitivity, new medications, recent travel, animal exposure. Laboratory work-up revealed new onset pancytopenia. On exam, photodistributed erythematous, indurated polycyclic plaques with central clearing. Two biopsies were collected at separate occasions, both revealed palisading neutrophilic granulomatous dermatitis (PNGD). Autoimmune workup was negative. Patient’s hospitalization was further complicated by acute renal failure. Renal biopsy revealed necrotizing and crescentic glomerulonephritis with C3-dominant deposits concerning for infectious etiology. Upon further extensive workup, patient was positive on Karius cfDNA and serology for Bartonella henselae. Patient endorsed a distant history of one cat scratch and was diagnosed with subacute endocarditis under the Duke criteria. He was started on rifampin and doxycycline, however he suffered from a neurologic mycotic aneurysm rupture and succumbed to the disease. PNGD is an inflammatory cutaneous reactive pattern with unknown pathogenesis. Most commonly associated with connective tissue disorders and arthritides, but can be seen in lymphoproliferative disorders and infections. There are other infrequent causes, such as this case of subacute bacterial endocarditis. The histologic findings of PNGD are consistent with the evolution of immune complex-mediated leukocytoclastic vasculitis that progresses to granulomatous features. A skin biopsy is required for diagnosis. Patients with cutaneous and histologic features of PNGD, who lack a diagnosis of associated systemic diseases, should be further evaluated with an extensive workup. There are currently no cases in the literature describing PNGD in Bartonella henselae subacute endocarditis.