Bartonella quintana Infection Manifesting as Leucocytoclastic Vasculitis Rash.

We present the first case described in the literature of leucocytoclastic vasculitis due to Bartonella quintana infection. A 73-year-old woman presented to the hospital with persistent fevers, retro-orbital headache, generalized weakness, and left lower thigh pain for 1 week. She was found to have truncal and proximal lower extremity papules and small plaques. Serology revealed Bartonella quintana immunoglobulin M (IgM) titer of 1:256 with undetectable Bartonella quintana immunoglobulin G (IgG) and undetectable Bartonella henselae IgG and IgM. Skin biopsy of an abdominal lesion revealed fibrinoid necrosis of vessel walls in the superficial and mid-dermis consistent with leucocytoclastic vasculitis. Doxycycline 100 mg orally twice daily was initiated, after which she had defervescence within 36 hours and rapid improvement of other presenting symptoms.