Abstract

A 19-year-old woman with B-thalassemia trait presented with fevers, headache, rash, and a subcuticular neck nodule. Review of systems revealed malaise, decreased appetite, photophobia, and phonophobia. She was febrile (Tmax 103F) and tachycardic (109 bpm). Physical examination demonstrated pink edematous papules coalescing into irregularly-shaped and linear plaques on the scalp, face, trunk, and extremities, and cervico-occipital lymphadenopathy. Labs revealed leukopenia (2.2x109/L), anemia (9.7 G/dL), and elevated CRP (26.47 mL), ESR (103 mm/hr), LDH (602 IU/L), and ferritin (827 ng/mL). Retroauricular skin punch biopsy demonstrated perivascular lymphohistiocytic inflammation, karyorrhexis, phagocytosis, and prominent dermoepidermal and follicular vacuolar interface change. Neutrophils were absent. CD68 immunohistochemical stain highlighted many dermal histiocytes. Inguinal lymph node biopsy revealed paracortical lymphohistiocytic inflammation and karyorrhexis. Immunohistochemical staining demonstrated an increased CD8+ T cell population within the necrotic regions. Antinuclear antibodies were negative. Parvovirus serologies resulted positive (IgM 1.70 IV, IgG 11.18 IV). Clinicopathologic correlation enabled a diagnosis of Kikuchi-Fujimoto disease (KFD) secondary to parvovirus infection. Systemic dexamethasone yielded excellent response. KFD is a self-limited condition defined by fevers and histiocytic necrotizing lymphadenitis that less commonly affects extranodal organs including the skin. KFD may clinically and histologically mimic systemic lupus erythematosus (SLE), emphasizing the need for clinicopathologic correlation to establish a diagnosis. Additionally, SLE may coexist with or be a complication of KFD. Comparative gene expression profiling is underway to juxtapose our patient’s specimens with histopathologic mimics, with an emphasis on comparing KFD to SLE.

Financial Disclosure:
No current or relevant financial relationships exist.