Extensive purely cutaneous Rosai–Dorfman disease responsive to acitretin

A 12-year-old girl presented with a 3-month history of a widespread nonpruriginous papulonodular eruption. Examination revealed a profusion of firm erythematous papules and nodules, distributed mainly on the cheeks, perioral region, upper trunk, thighs, and legs, mimicking a molluscum contagiosum eruption (1, 2). No fever or lymphadenopathy was noted. Complete blood count was normal. The erythrocyte sedimentation rate was elevated at 60 mm/h. Serum protein electrophoresis showed polyclonal hypergammaglobulinemia. Skin histopathology showed a dense nodular infiltrate of lymphocytes, neutrophils, and large vacuolated histiocytes in the reticular dermis. Some of these histiocytes engulfed, without destroying, lymphocytes and neutrophils (3, 4). Immunohistochemistry showed histiocytes positive for S-100 protein (Fig. 5) and macrophage-specific antibodies (CD68), and negative for CD1a. No systemic involvement was detected within a systemic work-up. A diagnosis of purely cutaneous Rosai–Dorfman disease was made. Because of the profusion of skin lesions, the patient was treated with acitretin (Soriatane®), 20 mg daily for 4 months, and surgical excision of the large lesions. The skin lesions cleared progressively and continued to clear spontaneously after treatment interruption (Fig. 6). Figure 1Open in figure viewerPowerPoint Papulonodular eruption located on the face, predominatly in the perioral region Figure 2Open in figure viewerPowerPoint Papulonodular lesions mimicking a molluscum contagiosum eruption Figure 3Open in figure viewerPowerPoint Dense infiltrate of lymphocytes, neutrophils, and large vacuolated histiocytes in the reticular dermis; moderate eosinophilic infiltrate (hematoxylin and eosin, ×100) Figure 4Open in figure viewerPowerPoint Some histiocytes engulf, without destroying, lymphocytes and neutrophils (hematoxylin and eosin, ×400) Figure 5Open in figure viewerPowerPoint Positivity of histiocytes for S-100 protein on immunohistochemistry Figure 6Open in figure viewerPowerPoint Total regression with scarring after 12 months