Parry-Romberg Syndrome: Progressive hemifacial atrophy

A 10-year-old boy presented with a complaint of facial deformity and crooked teeth, which developed after age six. There was no history of family members with similar complaints and no incidences of trauma or infection. 

Physical exam: Facial asymmetry was detected due to the hollowing of the cheek and chin, the malar hypoplasia, atrophy of facial skin and upper lip on the left side. There was a deviation of the nose and the angle of the mouth to the affected side with left microtia. Scant hair and eyebrows were present on the left side. There was atrophy of the masticator muscles on the left side.

Facial asymmetry with underdeveloped left hemifacial osseous and soft tissue structures. Osseous changes included hypoplastic left mandibular condyle with underdeveloped left mandibular ramus and coronoid process, left maxilla, left pterygoid plates and left zygomatic arch. Left maxillary and mandibular molar ridges were absent. Soft tissue changes included a reduction in the bulk of the right masticator muscles with overlying subcutaneous soft tissue. Atrophy involving the left side of the tongue and the cartilaginous portion of the left external auditory canal.

Parry Romberg syndrome is a rare self-limiting disorder causing progressive hemi facial atrophy of unknown aetiology [1,2]. It involves the skin and subcutaneous tissues initially, later affecting the underlying musculoskeletal structures insidiously with or without neurological symptoms [2].

A degenerative craniofacial condition with female preponderance, it affects both the cosmetic aspect and functionality of the affected hemi-face [1–3]. It has been noticed initially in young children and is shown to have a variable course spanning over 15 to 20 years [1–3]. Widespread aetiologies have been put forward, the most discussed is that of autoimmune inflammatory origin [4]. The syndrome has a strong genetic association, majorly of autosomal dominant inheritance [1–3]. Meanwhile, post-traumatic facial injuries, viral infections, endocrine disturbances, childhood radiation exposure and so on are the other popular proposed mechanisms [2,3].

Clinical features range from mild facial asymmetry to severe facial disfigurement usually associated with a demarcation line separating normal from atrophied tissue [1]. Ocular findings include ipsilateral enophthalmos, ptosis, and uveitis [1,2]. Oral tissues like the tongue, palate, teeth muscles of mastication etc are also affected. Neurological complications encountered include facial pain, ipsilateral headache, and seizures [1–3].

Imaging perspective

Radiological assessment with CT or MRI can be variable ranging from bone and soft tissue atrophy of the face usually restricted to one side, involving predominantly the ipsilateral facial bones, and muscles of mastication [1–3]. CNS involvement can range from subtle degenerative brain lesions like ipsilateral atrophy, calcifications, non-specific transient signal changes, ill-defined sulcations, and gyrations to remarkable focal structural-developmental defects like mono-ventricular enlargement, meningo-cortical dysmorphia, and chronic localised meningoencephalitis [1,2,5].

Prognosis, treatment, or therapeutic options

So far there has been no definite treatment regarding it, also considering the self-limiting nature it is known to stabilize over a span of a few years. Symptomatic management in terms of analgesics, anti-epileptic medications, steroids and immunosuppressants have been tried[1,5]. Cosmetic disfigurement has been approached surgically [2,3].