Cutaneous polyarteritis nodosa in patients presenting with atrophie blanche.

BACKGROUND: The term 'atrophie blanche' is used both as a descriptive term denoting ivory-white stellate scars on the lower limbs as well as a diagnostic label synonymous with livedoid vasculitis, an ill-defined entity. Medium-sized vasculitides, such as polyarteritis nodosa (PAN), occasionally present with ulceration resulting in ivory-white stellate scarring on the lower limbs and may potentially be misdiagnosed as livedoid vasculitis.
OBJECTIVES: To assess the occurrence, clinical and immunopathological features of medium-sized vasculitis in patients presenting with atrophie blanche without clinical and/or compression duplex ultrasonographic evidence of venous insufficiency.
METHODS: We retrospectively evaluated patients presenting with atrophie blanche at the Department of Dermatology of Johns Hopkins Medical Institutions, from April 1996 until April 2002, following the diagnostic guidelines for leg ulcers of the Division of Immunodermatology. Deep and multiple skin biopsies were performed for histology. Investigations for underlying vasculitis, thrombophilia, nerve conduction studies and compression duplex ultrasonography of the lower extremities were performed in all patients.
RESULTS: Of 29 consecutive patients presenting with atrophie blanche, six had underlying medium-sized vasculitis consistent with PAN, three of whom had previously been diagnosed to have segmental hyalinizing vasculitis/vasculopathy (livedoid vasculitis/vasculopathy) on superficial biopsies. All six patients with cutaneous PAN were women with a median age of 36.5 years (range 34-46) and with a median duration of the disease prior to diagnosis of 18 years (range 3-30). Of the six cutaneous PAN patients, four had neurological involvement evidenced by clinical symptoms and nerve conduction studies. No evidence of any other extracutaneous involvement was found. Erythrocyte sedimentation rate and tests for vasculitis and thrombophilic were normal in all six patients. None had evidence of venous insufficiency. Immunosuppressive therapy was effective in controlling PAN-associated cutaneous and neurological disease. Of the remaining 23 patients, two had antiphospholipid syndrome and one had homocystineaemia; all three also had evidence of venous insufficiency. One patient had multiple myeloma-associated type I cryoglobulinaemia and 19 patients had venous insufficiency alone. None of the non-PAN patients had abnormalities in the nerve conduction studies.
CONCLUSIONS: In patients presenting with atrophie blanche without evidence of venous insufficiency and thrombophilia, PAN should be excluded, particularly in the presence of mononeuritis multiplex. Repeated and deep biopsies are often necessary to reveal the accurate underlying pathology of necrotizing medium-sized vasculitis in the reticular dermis and the subcutis, especially in the setting of atrophie blanche lesions. Immunosuppressive therapy was effective in controlling the PAN-associated clinical manifestations.