<unk>  (PRS) is a rare disease characterized by progressive shrinkage and degeneration of the tissues beneath the skin, usually on only one side of the face (hemifacial atrophy) but occasionally extending to other parts of the body. An autoimmune mechanism is suspected, and the syndrome may be a variant of localized scleroderma, but the precise cause and pathogenesis of this acquired disorder remains unknown. It has been reported in the literature as a possible consequence of sympathectomy. The syndrome has a higher prevalence in females and typically appears between 5 and 15 years of age. In addition to the connective tissue disease, the condition is sometimes accompanied by neurological, ocular and oral symptoms. The range and severity of associated symptoms and findings are highly variable.
Parry–Romberg syndrome
Smith–Fineman–Myers syndrome
MORM syndrome
Sly syndrome
Imerslund–Gräsbeck syndrome
WHIM syndrome
Lujan–Fryns syndrome
Senior–Løken syndrome