Overview

Parry-Romberg syndrome (PRS) is a rare disorder characterised by gradually progressing atrophy (shrinkage) of the skin, muscles, bone, and cartilaginous structures of one half of the face. It is also known as progressive hemifacial atrophy, progressive facial hemiatrophy, or idiopathic hemifacial atrophy. This condition presents itself in early childhood or teenage years and is more common in females.¹ 

PRS poses significant challenges related to facial disfigurement, as well as associated neurological, psychological, and ophthalmological manifestations. Neurological symptoms are observed in 15-20% of cases. The exact cause of PRS remains unclear, and it appears to occur randomly. PRS is an autoimmune disorder, meaning the immune system mistakenly attacks its own cells. It is also considered a form of localised scleroderma or morphea, as the two conditions show similarities in facial features.^1,2

Clinical course and symptoms

The disease shows a progressive course and reaches a burnout phase within two to 20 years of active disease. This can potentially accelerate the disease activity in some individuals and further worsen facial disfigurement. In addition, stress and surgery may be possible triggers for this acceleration.^3,4

PRS can be distinguished from scleroderma by assessing the following criteria:¹ 

1. Shrinkage of one side of the face
2. Absent or minimal signs of prior inflammation or induration (tissue hardening)
3. Skin atrophy with thin, soft skin and no sclerosis

People with this condition may also experience eye-related problems. These can include sunken eyes (known as enophthalmos), increased pressure in the eyes (glaucoma), inflammation of the optic nerve (optic neuritis), inflammation of retinal blood vessels (retinal vasculitis), and difficulty controlling eye movements (oculomotor dysfunction).¹ 

In addition, the lower part of the face is often affected, with deterioration or loss of tissue on one side of the tongue, gums, and roof of the mouth (hard palate). In some individuals, a line called morphoea en coup de sabre, resembling a ‘stroke from a sword’, appears on the scalp or forehead.^1,5 

Neurological symptoms

The common neurological symptoms include:¹ 

• Generalised seizures, or seizures that last longer than five minutes or occur repeatedly without recovery in between (status epilepticus): Seizures begin within 3 years of the onset of the symptoms 
• Migraines
• Trigeminal neuralgia: This is characterised by episodes of severe pain in facial regions supplied by the trigeminal nerve, such as the mouth, cheek and nose
• Movement disorders: Muscle spasms, uncontrolled muscle cramps and spasms (dystonia), neck muscle spasms (torticollis), and changes in walking (gait disturbances)
• Speech abnormalities: difficulty using or understanding language, such as forming clear sentences (aphasia) and slurred speech caused by weakened muscles (dysarthria)  
• Limb abnormalities: Limb weakness, pain, or atrophy in rare cases
• Neuropsychiatric manifestations: Cognitive disturbances, hallucinations, and mental disorders

Causes

Although the cause is poorly understood, several theories have been proposed to explain the development of this syndrome. Among the suggested causes are traumatic events such as head injuries during early childhood, preceding viral infections, dysregulated neural crest cell migration, inflammation or dysfunction of the cervical sympathetic chain.¹

However, the autoimmune theory is widely accepted, where the body’s immune system mistakenly produces autoantibodies to destroy its own cells. This theory is further supported by the presence of coexisting autoimmune conditions such as systemic lupus erythematosus and rheumatoid arthritis, as well as clinical improvement through the use of immunosuppressive therapies during active disease.^1,6

Diagnosis

The diagnosis of PRS is primarily based on characteristic clinical features, as there is currently no universally accepted diagnostic criterion. Baseline imaging may help detect neurological symptoms; some of the recommended imaging methods include:^1,3

• MRI scans – Typical findings on MRI show hyperintense or extensive white matter lesions. These are prominent on the ipsilateral side (affected side)
• CT scans -  CT scans reveal buildups of calcium deposits (calcifications) and changes in the density of white matter

If a seizure disorder is suspected, a test called an electroencephalogram (EEG) may be recommended to measure the brain’s electrical activity. When abnormalities are seen in the EEG, they are usually found on the same side of the brain as the symptoms and typically show localised brain activity.³

Single-photon emission CT (SPECT) may be useful to identify possible brain damage as it can examine the blood flow in different parts of the brain. Some individuals with temporal lobe epilepsy show reduced blood flow in the parieto-occipital region on the affected side. Importantly, SPECT can also reveal abnormalities even when MRI findings appear normal.³

Therefore, a combination of cerebral blood flow analysis using SPECT, observation of central nervous system-related symptoms, and initial evaluation using  MRI may provide a clearer overall picture of central nervous system involvement, which can help to better predict disease outcomes.^1,3

Treatment approaches

There is currently no definite cure for PRS due to its rarity and progressive nature, and management is usually tailored to each case.⁴

Medical management 

The main goal of treatment is to halt the active disease process. 

Methotrexate (MTX) is the standard therapy and is often combined with a steroid, prednisone, to reduce inflammation and fibrosis. Other immunosuppressive agents have demonstrated variable success in individuals who do not respond to treatment with MTX. Ultraviolet A (PUVA) therapy and psoralen have been reported to stop disease progression in a few cases of PRS.³

Surgery

Surgical treatment for PRS often requires a multi-speciality approach involving dermatologists, neurologists, plastic surgeons, dentists and psychologists. The purpose of surgery is to address cosmetic concerns and improve the function of involved facial structures.³

Living with PRS

Regular and long-term monitoring is important to identify potential complications, monitor disease progression and optimise treatment outcomes. Although neurological symptoms can often be well-managed, they may still result in some long-term difficulties. This emphasises how serious the condition can be and why ongoing care and monitoring are important.⁴

Future outlook

Despite ongoing research, the exact underlying causes of PRS remain unclear, emphasising the critical need for extensive investigations to understand how it develops. More precise and effective methods of treatment can be developed by gaining a deeper understanding of the syndrome's mechanisms, ultimately improving the quality of life for individuals affected by this rare disorder. Continued research is essential for advancing innovative therapeutic solutions and enhancing healthcare outcomes for those grappling with PRS.⁴

FAQs

At what age does Parry-Romberg syndrome start?

Typically, the onset of symptoms occurs within the first two decades of life. Though instances of late-onset PRS occurring in the sixth and seventh decades of life have also been recorded.⁴

Is Parry-Romberg syndrome hereditary?

Most cases occur randomly, and only a few individuals with the same disease in the same family have been reported. So it is not known if the disease runs in families. However, there has been a case report of two first cousins who have developed the syndrome, highlighting a possible genetic link.⁵

When does Parry-Romberg syndrome stop?

The syndrome tends to slowly progress over a two to 20-year period, before spontaneously entering a stable phase where disease progression halts.

Can Parry-Romberg syndrome be prevented?

No, PRS can’t be prevented as a vast majority of cases are sporadic, and the exact underlying cause is unknown.

Summary

Parry-Romberg Syndrome (PRS) is a rare condition marked by the gradual shrinkage of facial tissues—skin, muscles, bones, and cartilage—usually affecting one side of the face. 

The exact cause remains unknown, but PRS is predominantly considered to be an autoimmune disorder, supported by links to other autoimmune diseases and a better response to immunosuppressive therapy.

Neurological involvement occurs in about 15–20% of cases, presenting as seizures, migraines, trigeminal neuralgia, movement and speech disorders, limb weakness, and psychiatric symptoms. Long-term monitoring is vital to manage complications and progression.

Diagnosis is mainly clinical, supported by imaging (MRI, CT). Treatment aims to control active disease with methotrexate, steroids, or other immunosuppressants, while surgical reconstruction addresses facial deformities and restores function.