This woman’s palpable purpura with edema in her lower extremities was consistent with cutaneous leukocytoclastic vasculitis (LCV).
LCV is characterized by the circulation of immune complexes that promote activation of complement, leading to endothelial injury and palpable purpura. Pain, arthralgia, cutaneous ulceration, and constitutional symptoms may be observed. About 50% of LCV cases are idiopathic. Identified causes include infection (including syphilis infection), drugs, malignancy, and connective tissue disease.
Systemic involvement must be ruled out in any patient with cutaneous LCV. The work-up is based on the individual patient assessment and may include a complete blood count with differential, complete metabolic panel, inflammatory markers, urinalysis, hepatitis panel, anti-nuclear antibody, rheumatoid factor, anti-neutrophil cytoplasmic antibodies, cryoglobulins, serum protein electrophoresis, and serum complement. A cutaneous punch biopsy for both hematoxylin and eosin (H&E) and direct immunofluorescence (DIF) confirms the diagnosis of LCV.
For uncomplicated LCV cases without systemic involvement, treatment is generally supportive. Any identified underlying cause should be addressed. Analgesics may be considered for pain. Systemic therapy is indicated for patients with cutaneous ulceration, systemic vasculitis, or recurrent cases; this therapy may include colchicine, dapsone, corticosteroids, mycophenolate mofetil, and methotrexate.
In this patient’s case, a punch biopsy of the left lower extremity showed findings consistent with cutaneous LCV. She denied a history of intravenous drug use or initiation of new medications. Labs were notable for an elevated erythrocyte sedimentation rate, c-reactive protein, and elevated creatinine.
Incidentally, she was found to be 32-weeks pregnant, went into pre-term labor while admitted, and delivered her baby without complication.
She had a reactive treponemal antibody, with rapid plasma reagin titer of 1:128, which confirmed a diagnosis of syphilis. She was treated with 1 dose of intra-muscular penicillin G while an inpatient. Her arthralgias improved during her hospitalization without initiation of steroids or other immunomodulatory therapy. Outpatient follow-up was expected to consist of completion of 3 total doses of IM penicillin, as well as renal studies, given her elevated creatinine.
Photo courtesy of Cyrelle R. Fermin, MD, and text courtesy of Cyrelle R. Fermin, MD, Department of Dermatology, and Daniel Stulberg, MD, FAAFP, Department of Family and Community Medicine, University of New Mexico School of Medicine, Albuquerque.