Coexistence of Polyarteritis Nodosa of the Vulva and Retina in a Behçet's Disease Patient: A Case Report.

Polyarteritis nodosa (PAN) is a multisystem disease that may affect the vessels of multiple organ systems. It has clinical variants including single-organ disease and cutaneous-only PAN. To our knowledge, this is a unique case report describing the coexistence of PAN of the vulva and retina in a Behçet's disease (BD) patient.  We report a case of a 31-year-old Lebanese woman with painful genital ulcers and multiple oral aphthae associated with arthralgia, light flashes, blurry vision, and photosensitivity. There were well-defined, punched-out erosions over the buccal and gingival mucosa; specifically, multiple punched-out, deep ulcers with unremarkable borders and black eschar involving two-thirds of both labia majora and minora sparing the clitoris with bilateral inguinal lymphadenopathy. Dilated fundus examination showed a few cotton wool spots and intraretinal hemorrhage. Fundus fluorescein angiography showed multiple arteriolar infarctions involving the macula in both eyes, more so in the right eye. Vulvar biopsy was consistent with PAN due to the involvement of a medium-sized subcutaneous artery and showed neutrophilic infiltration of its wall. Stain for elastic lamina showed medium-sized subcutaneous artery involvement. After ruling out infectious aetiologies, she was managed by intravenous pulse methylprednisolone 1,000 mg for three days, followed by oral prednisolone 50 mg with a slow taper, oral colchicine 0.5 mg twice daily, and adalimumab 40 mg once every two weeks to stop the progression of the ocular insult and genital mutilation. There was significant improvement of the ulcer with no new cutaneous or systemic manifestations. This case report highlights the importance of considering PAN-like lesions in cases of Behçet's disease. We emphasized the addition of cutaneous PAN as one of the cutaneous manifestations of BD.