A Case of Papular Mucinosis / 대한피부과학회지

ABSTRACT

Papular mucinosis, or lichen myxedematosus, is a rare cutaneous disease characterized by papular-lichenoid eruptions, mucin deposition, paraproteinemia, no abnormalities of thyroid function and IgG or IgM deposition in the reticular dermis or just below the epidermis in about 35% cases on direct immunofluorescence study. We report a case of papular mucinosis in a 48-year-old male, who noticed the skin colored or yellowish waxy papules on his upper arm 1 year ago. Since then, similar lesions developed on his upper extremities, upper trunk, and neck during last year. Histopathological findings of the lichenoid papules showed that the collagen fibers in the upper dermis are loosly arranged and separated by amorphous materials. These amorphous materials were positve with colloidal iron stain. Serum protein electrophoresis showed no abnormal bands and an abnormal paraprotein was not detected. Direct immunofluorescenc study of a skin biopsy specimen showed a granular IgM deposit in the papillary dermis. This is the sixth case of papular mucinosis reported in Korea, but is the first case showing IgM deposit in the skin by immunofluorescence study.