Parry–Romberg syndrome

Parry–Romberg syndrome (PRS) is a rare disease presenting in early childhood 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. There has been only one case report of the syndrome appearing in older adults: a 43-year-old woman with symptoms appearing at the age of 33.

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.

Initial facial changes usually involve the area of the face covered by the temporal or buccinator muscles. The disease progressively spreads from the initial location, resulting in atrophy of the skin and its adnexa, as well as underlying subcutaneous structures such as connective tissue, (fat, fascia, cartilage, bones) and/or muscles of one side of the face. The mouth and nose are typically deviated towards the affected side of the face.

The process may eventually extend to involve tissues between the nose and the upper corner of the lip, the upper jaw, the angle of the mouth, the area around the eye and brow, the ear, and/or the neck. The syndrome often begins with a circumscribed patch of scleroderma in the frontal region of the scalp which is associated with a loss of hair and the appearance of a depressed linear scar extending down through the midface on the affected side. This scar is referred to as a "coup de sabre" lesion because it resembles the scar of a wound made by a sabre, and is indistinguishable from the scar observed in frontal linear scleroderma.

In 20% of cases, the hair and skin overlying affected areas may become hyperpigmented or hypopigmented with patches of unpigmented skin. In up to 20% of cases the disease may involve the ipsilateral (on the same side) or contralateral (on the opposite side) neck, trunk, arm, or leg. The cartilage of the nose, ear and larynx can be involved. The disease has been reported to affect both sides of the face in 5 to 10% of cases.

Symptoms and physical findings usually become apparent during the first or early during the second decade of life. The average age of onset is nine years of age, and the majority of individuals experience symptoms before 20 years of age. The disease may progress for several years before eventually going into remission (abruptly ceasing).

Neurological abnormalities are common. Roughly 45% of people with Parry–Romberg syndrome also have trigeminal neuralgia (severe pain in the tissues supplied by the ipsilateral trigeminal nerve, including the forehead, eye, cheek, nose, mouth and jaw) and/or migraine (severe headaches that may be accompanied by visual abnormalities, nausea and vomiting).

10% of affected individuals develop a seizure disorder as part of the disease. The seizures are typically Jacksonian in nature (characterized by rapid spasms of a muscle group that subsequently spread to adjacent muscles) and occur on the side contralateral to the affected side of the face. Half of these cases are associated with abnormalities in both the gray and white matter of the brain—usually ipsilateral but sometimes contralateral—that are detectable on magnetic resonance imaging (MRI) scan.