Successful treatment of Rosai–Dorfman disease with low-dose oral corticosteroid

We present herein a Japanese case of Rosai–Dorfman disease (RDD) in which cutaneous manifestations completely remitted after treatment with low-dose oral corticosteroid. A 69-year-old Japanese man presented with a 1-year history of enlarged submandibular lymph nodes and subsequent nasal and pharyngeal bleeding. RDD was diagnosed based on biopsy results from a lymph node in the left parotid region. The patient had also noted several skin eruptions that repeatedly appeared and disappeared on the face and arms. Biopsies were taken from skin eruptions on the face and cuboidal fossa. Both biopsy specimens showed dense, well-demarcated infiltration of histiocytes, lymphocytes and multinucleated giant cells from just under the epidermis to the subcutaneous tissue. These histiocytes were positive for CD68 and S-100, but negative for CD1a, and some displayed emperipolesis. Given the histopathological findings and the fact that the patient was suffering from RDD, skin lesions were diagnosed as cutaneous manifestations of RDD. Cutaneous lesions gradually began to persist concomitant with enlargement of extranodal lymphadenopathy in the nasopharyngeal area. Increasing respiratory obstruction prompted a trial with oral prednisolone commencing at 0.4 mg/kg per day. Both the lymphadenopathy and skin lesions responded quickly. Within 3 months, all his skin lesions disappeared completely with almost complete resolution of lymphadenopathy. Twelve months after the beginning of oral prednisolone therapy, slight recurrence of mucosal and cutaneous lesions appeared, but disappeared quickly with an increase in prednisolone to 0.3 mg/kg per day. Low-dose prednisolone appeared very effective in the case of RDD.