Idiopathic progressive hemifacial atrophy

Introduction

Idiopathic progressive hemifacial atrophy (PHA), also termed Parry–Romberg syndrome, occurs in school-aged children with a slight female and no racial predominance. PHA is typically characterized by slow progressive unilateral atrophy of the skin and soft tissue of the face, with deeper involvement of the underlying muscles and osteocartilaginous structures resulting in both aesthetic and functional orofacial issues. PHA is usually restricted to one side of the face, though bilateral facial involvement has been reported. Hemiatrophy of the ipsilateral extremity (arm and/or leg) and trunk may occur, though other sites of localized scleroderma, including linear bands or plaques on the neck, trunk, and extremities are observed more commonly (approximately 5%–15%) ( Fig. 27.1 ). It is likely multifactorial in its etiopathogenesis, including a prevalent autoimmune basis provided by histologic evidence of a lymphocytic neurovasculitis (skin and brain), abnormalities on brain imaging consistent with an inflammatory and/or vasculitic process (see Fig. 27.6 ), and laboratory findings in the sera (autoantibodies) and the CSF (oligoclonal bands), supportive of this process.

PHA is increasingly considered to be on the same spectrum of disorders as its companion disease, “ en coup de sabre ” (ECDS), French for “like the cut of a sword”, which describes the indentation of the scalp and forehead of these patients. Both PHA and ECDS are considered to be subtypes of localized scleroderma, linear scleroderma affecting the head, with “typical” PHA having more subcutaneous and bone atrophy (less obvious cutaneous findings) and ECDS having a hyperpigmented sclerotic cutaneous linear band with associated alopecia and linear skull depression (see Fig. 27.5 ). Many patients with craniofacial scleroderma, linear scleroderma affecting the head (face and/or scalp), have a mixture of the two conditions ( Fig. 27.2 ). When investigated, both PHA and ECDS had the same type and frequency of extracutaneous clinical manifestations, such as dental, eye, and neurologic involvement, further supporting that these conditions are on the same spectrum ( Fig. 27.1 ). Treatment often depends on the clinical assessment of the disease activity state. If cutaneous or extracutaneous manifestations appear to be advancing or show evidence of inflammation (as opposed to fibrosis), then systemic therapy with immunosuppression is warranted. This can be followed by surgical intervention when deemed in the inactive state ( Algorithm 27.1 ).

Algorithm 27.1

Adapted from Glaser DH, Schutt C, Schollaert-Fitch K, Torok K. Linear scleroderma of the head – Updates in management of Parry Romberg syndrome and en coup de sabre: A rapid scoping review across subspecialties . Eur J Rheumatol. 2020;7(Suppl 1):S48–S57 .

†For specific treatment regimens, see reference 35.Essential diagnostic and management algorithm for ECDS/PRS. There are no universal diagnostic laboratory or imaging criteria to establish diagnosis. Serial imaging as well as inflammation/immune activation markers may be helpful in monitoring response to treatment.

Historical perspective

The clinical finding of hemifacial atrophy was initially described in the writings of Dr. Caleb Hillier Parry. However, Parry’s medical writings were published posthumously on account of a stroke he suffered in 1816, which forced him to cease the practice of clinical medicine. With his daughter’s assistance, he continued his observations in writing, including observations about primary hemifacial atrophy. In 1825, three years after his death, his son Charles Parry published these writings, which included the initial description of this disorder.

In 1846, Dr. Moritz Heinrich Romberg, who had revolutionized the field of neurology in Europe by publishing the first systematic textbook on neurology, further described the clinical manifestations of hemifacial atrophy. In parallel, Thomas Addison inappropriately described circumscribed scleroderma as Addison’s keloids in 1854. This was corrected and modernized by Erasmus Wilson as morphea in 1865. Charles Fagge subsequently coined the term “ en coup de sabre” (by the strike of the sword) to describe localized scleroderma, or morphea, of the head and face in 1867, which was subsequently popularized by Jonathan Hutchinson in 1869. In 1871, Albert Eulenburg, a German neurologist, coined the term “progressive hemifacial atrophy” (PHA) and in 1945, Wartenberg published an extensive review article covering its clinical features.

The pathogenesis of PHA is basically unknown and there have been multiple suggestions for this etiology over the years. Most recently, Mulliken called this a “lymphocytic neurovasculitis” involving chronic cell-mediated vascular injury with incomplete endothelial regeneration regarding the involvement of the long branches of the trigeminal nerve.

Historically, consideration has been given to the concept that congenital hemifacial atrophy may be a type of localized scleroderma, especially when it is noted in the forehead as the “ en coup de sabre ” or “mark of the saber”. Whether these two are different entities or whether this is the same disorder in a different form (i.e., localized scleroderma) is still not entirely clear in the literature, there is increasing consensus that the two disorders lie on opposite ends of a spectrum.

In more recent years, Rogers reviewed 772 cases of PHA and there was a further definitive review in 1983 by Lewkonia and Lowry. The disorder has been shown to occur with other body asymmetries and has been described with a host of neurologic features. Many neurology articles point out that, while less common, bony deformities can be present along with the soft-tissue defect. Bilateral cases have been reported but are unusual.

In the timeline of treatment options for hemifacial atrophy, it is evident that with increased availability of modern reconstructive surgical techniques, the treatment of this disorder has gradually changed over the years. Blair, in the 1930s, and Sarnat and Neumann, in the 1950s, described the use of local flaps to augment the soft-tissue deficiency. Tube pedicles were used about the same time to transfer soft tissue into the defect from remote sites with its own blood supply and for many years this was the treatment of choice. The tube pedicles were de-epithelialized with appropriate amounts of fat and dermis used for the reconstruction. In a case noted in this chapter (from the 1960s), Barsky used abdominal tissue, which was transferred to the face using this technique.

In the 1950s, bone and cartilage grafts gained favor. Campbell, and later Converse, described the use of onlay iliac bone graft to augment areas of atrophy. Later Longacre advocated split costal bone for the same purpose. With the advent of more biocompatible metals, Kiskadden and McGregor described the use of tantalum for reconstruction of the hard-tissue defect. In the 1970s, Rees and Ashley and colleagues published their experience of treating PHA with silicone injections. Several publications followed regarding this alloplastic approach. In the 1970s, Wells and Edgerton described the use of free dermis and fat from the lower abdomen as a filler material. Fat transfer techniques have continued to be expanded upon with robust safety profile and durable outcomes, especially in those with mild–moderate facial asymmetry.

The era of free tissue transfer saw applications for the treatment of PHA. In the 1970s, Wallace described the use of an omental free flap for soft-tissue augmentation. In 1985, Jurkiewicz similarly described the use of a free, vascularized tissue for patients with PHA. By the early 1990s, a series of articles appeared by Siebert and Longaker and others using free parascapular tissue for the treatment of this disorder of severely affected patients and at the present time various modifications of this technique seem to be the standard of care.