A Case Report of Papulonodular Mucinosis Associated with Unclassified Autoimmune Connective Tissue Disease

Abstract

Papulonodular mucinosis (PNM) is an uncommon but distinctive cutaneous manifestation of autoimmune connective tissue disease mainly associated with lupus erythematosus. Mucin deposition in the dermis is a common histologic finding. The pathogenesis is still uncertain but it is thought to be due to increased glycosaminoglycans production by dermal fibroblast stimulated by some cytokines or immunoglobulins. In terms of treatment, PNM is usually unsatisfactory. Many modalities have been suggested including glucocorticosteroids (topical, intralesional or systemic), antimalarial agents, retinoids, cyclophosphamide, methotrexate, plasmapheresis or surgical procedures such as laser and excision may have benefits.

We report a case of 45-year-old female presented with a 5-years history of multiple erythematous hyperpigmented papules, nodules on trunk and skin colored papules coalescing to plaques on both forearms and knuckles. The patient denied systemic symptoms and the physical examination showed only Raynaud phenomenon. The histopathology and special staining were compatible with dermal mucinosis. Laboratory investigation showed high titer antinuclear antibodies and weakly positive anti-Jo1 while other serological tests for autoimmune disease were normal. The final diagnosis of papulonodular mucinosis associated with unclassified autoimmune connective tissue disease (AI-CTDs) was made as there was neither symptom nor laboratory result of definite AI-CTDs. Clinical improvement was seen after 3 months of oral methotrexate and topical glucocorticoids.