Histopathology of a granulomatous lobular panniculitis in acute Q fever: a case report

Q fever is a zoonotic infection caused by Coxiella burnetii. Two forms of the disease have been described: an acute form with pneumonia, hepatitis or a flu‐like syndrome; and a chronic form in which endocarditis is the most frequent clinical expression. We report a 77 year old male with fever and an erythematous nodule on the right leg. Biopsy revealed a granulomatous lobular panniculitis with some granulomas rimmed by an eosinophilic material, giving a “doughnut” or “fibrin‐ring” appearance. Q fever serological studies were positive. Cutaneous signs, among them panniculitis, are probably underestimated during the acute phase of the disease, and recognizing different granulomatous patterns may contribute to the diagnosis. Soulard R. Histopathology of a granulomatous lobular panniculitis in acute Q fever: a case report.