Nodular cutaneous mucinosis as an initial presentation of systemic lupus erythematosus

It is well recognized that the deposition of mucin occurs in areas of eruption in patients with lupus erythematosus. However, nodular cutaneous mucinosis is regarded as a rare distinctive cutaneous mucinosis in which the mucin deposition occurs in areas other than the sites of eruption in patients with systemic lupus erythematosus and manifests as a clinically specific lesion. Although several cases have been described in the literature, there have been only two reported cases in Korean literature. Thus, we report an interesting case of nodular cutaneous mucinosis that occurred in a young man. A 16-year-old man visited our clinic presenting with multiple soft subcutaneous nodules on his back for 6 months. He denied any other symptoms. Histological examination showed diffuse mucin deposition throughout the superficial and mid-reticular dermis. The abnormal laboratory values were as follows: a positive antinuclear antibody, increased anti-dsDNA, and reduced WBC count and C3 levels. He was diagnosed with nodular cutaneous mucinosis with systemic lupus erythematosus and treated with oral hydroxychloroquine and methylprednisolone. Our report is of interest owing to the rarity of developing nodular cutaneous mucinosis as an initial presentation of systemic lupus erythematosus.