A case of progressive crossed hemiatrophy mistaken as panniculitis.

Progressive crossed hemiatrophy is an extremely rare clinical type of facial hemiatrophy that presents primarily as unilateral facial atrophy and contralateral trunk or limb involvement. The undistinguishable clinical manifestation and pathological changes complicate diagnosis, especially at the onset of the disease when presenting with less clinical evidence. Here, we report a case of a 9-year-old boy started with left scalp induration, following with subcutaneous tissues atrophy on the right trunk. He was mistaken as panniculitis based on the pathologic findings and treated with topical tacrolimus without any improvement. Immune-related tests were implemented to exclude connective tissues. Imaging examinations such as magnetic resonance was conducted to evaluate the range and degree of the involvement of the skin, soft tissue, and cranial changes. Although no effective treatment to hold back the progress has been reported so far, surgeries might work to restore the appearance to some extent or improve central nerves symptoms if they exist.