| A rare acquired disorder with characteristics of unilateral slowly progressive atrophy of the skin and soft tissues of half of the face leading to a sunken appearance. Muscles, cartilage and the underlying bony structures may also be involved. Usually presents during the first 20 years of life and may start with alopecia, hair hypopigmentation, and atrophy. May extend to the upper lip and or one side of the tongue and the masticatory muscles, resulting in deviation of the nose and or mouth toward the affected side. Rarely both sides of the face and the skin on the arms/trunk/leg or the entire body may be involved. Autoimmunity may be a cause along with facial or head trauma, meningoencephalitis, abnormal development or hyperactivity of the sympathetic nervous system, neuro-vasculitis, angiogenesis anomalies, and slow viral infections. Sporadic but rare familial cases have been reported. |
