Idiopathic progressive hemifacial atrophy

Idiopathic progressive hemifacial atrophy (PHA), also termed Parry-Romberg syndrome, occurs in school-aged children with a slight female and no racial predominance. PHA is typically characterized by slow progressive unilateral atrophy of the skin and soft tissue of the face, with deeper involvement of the underlying muscles and osteocartilaginous structures resulting in both cosmetic and functional orofacial issues. PHA is usually restricted to one side of the face, though bilateral facial involvement has been reported, and hemiatrophy of the ipsilateral extremity may occur or localized scleroderma lesions at distant sites. It is likely multifactorial in its etiopathogenesis, with an autoimmune basis providing histologic evidence of a lymphocytic neurovasculitis (skin and brain); abnormalities on brain imaging consistent with an inflammatory and/or vasculitic process; and laboratory findings in the sera and the CSF. Treatment often depends on the clinical assessment of the disease activity state. If cutaneous or extracutaneous manifestations appear to be advancing or show evidence of inflammation (as opposed to fibrosis), then systemic therapy with immunosuppression is warranted. This can be followed by surgical intervention when deemed in the inactive state. Surgical intervention generally involves replacement of the deficient soft tissue either by fat grafting or free tissue transfer.