Plaque-like cutaneous mucinosis associated with pain: A case report

Plaque-like cutaneous mucinosis (PCM) is a rare atypical subtype of Lichen myxedematosus, characterized by hyperpigmented plaques typically found on the midline trunk. We report the case of a 26-year-old woman with a 1-year history of painful, pruritic, hyperpigmented plaques over her spine. Physical examination revealed soft plaques in the midline of the back, and histopathology showed dermal mucin deposition, consistent with PCM. The presented case is notable as the first reported instance of PCM presenting with lesional pain. We propose that mechanical stress, likely due to repeated friction at the site of spinous processes, contributed to the development of pain. The fact that pain lessened after the use of a lumbar support pillow and gaining weight supports our hypothesis. Our case demonstrates the importance of considering PCM in the differential diagnosis of hyperpigmented plaques and highlights the need for further research to elucidate its underlying pathogenesis and optimize treatment strategies.