Linear scleroderma en coup de sabre is a particular form of linear scleroderma that may not truly be related to other forms.
“En coup de sabre” is a French phrase that was used to describe the injuries of foot soldiers struck on the head by the sword of a cavalry soldier riding a horse. If the foot soldier survived this injury, there would be a scar and thickened skin involving one side of the forehead and extending along the scalp toward the back.
Children with linear scleroderma en coup de sabre have an area of thickened, abnormal skin that resembles this scar, but they usually do not have significant underlying problems. However, the distinction between linear scleroderma en coup de sabre and Parry Romberg syndrome is unclear.
Parry Romberg syndrome is a gradually progressive facial hemiatrophy. [A facial hemiatrophy is a condition involving atrophy of the muscles in one half of the face.]
In a full-fledged case, there is significant deformity, with one entire side of the face smaller than the other. This is in sharp contrast to typical linear scleroderma en coup de sabre, where the abnormality is confined to the forehead.
While the changes of linear scleroderma en coup de sabre are usually confined to the skin, in Parry Romberg syndrome there is an increased frequency of underlying changes in the brain.
The difference between linear scleroderma en coup de sabre and Parry Romberg syndrome is best exemplified by involvement of the tongue in Parry Romberg syndrome. Not only is one side of the face smaller, but also one side of the tongue is smaller. Thus, Parry Romberg syndrome is clearly not a condition of the skin alone.
However, both conditions may begin the same way and there are children who have areas of atrophic facial skin that do not clearly fit either category.
These illnesses typically begin in the first or second year of life. Most often, the family will describe having noticed a pinkish lesion just to one side of the middle of the forehead. Since children in this age group fall frequently while learning to walk, most families assume the child simply banged his or her head. Over a few weeks, the lesion does not go away as expected. Instead, the veins may become more noticeable in the pink area.
The lesion on the forehead is often present for months before the family begins to notice indentation of the bone under the pink skin. On careful examination, there may be a continuation of the abnormal skin underneath the hairline. In other children, the area of pink skin extends further down the face and along the side of the nose over time. Linear scleroderma en coup de sabre should not extend below the eyelid. True Parry Romberg syndrome involves the entire side of the face. Some children fall in between.
Because there are children with varying degrees of involvement, there is no uniform agreement regarding where linear scleroderma en coup de sabre ends and Parry Romberg syndrome begins.
If there is involvement of the tongue, it is Parry Romberg syndrome. I also believe all children with involvement of the brain underneath the lesions have Parry Romberg syndrome and not linear scleroderma en coup de sabre, but no one is sure. We are not even sure the diseases are truly different.
Laboratory abnormalities are minimal in children with both of these disorders. As with other forms of linear scleroderma, some children have positive tests for ANA, but tests for anti-dsDNA, FR, Scl-70, anticentromere antibody, and routine blood tests including CBC and ESR, should be normal. These children should not have abnormal muscle enzymes or muscle weakness.
Treatment and prognosis for this group of children remain uncertain. If the lesions are confined to the scalp and forehead, as in typical linear scleroderma en coup de sabre, they seem responsive to methotrexate. The long-term outlook for children with linear scleroderma en coup de sabre is generally excellent. In most cases, the cosmetic deformity is minimal and can be well concealed by the hair.
Some children with linear scleroderma en coup de sabre have been described as having underlying neurologic involvement. Again, I believe this is more likely a manifestation of Parry Romberg syndrome, but the lines differentiating the two conditions are not clearly drawn. Children with linear scleroderma en coup de sabre may have some difficulties dealing with the impact of the cosmetic deformity. However, the prognosis for a normal and productive life is excellent.
Unfortunately, children with Parry Romberg syndrome and facial hemiatrophy are rarely recognized before the atrophy has become significant. In most cases, it does not appear appropriate to intervene medically at that point. However, in the hands of an experienced plastic surgeon that has worked with these children, cosmetic surgery is practical. There are multiple special considerations involved in this surgery and it should be only done by a team experienced in dealing with such children.
A significant percentage of children with Parry Romberg syndrome also have underlying central nervous system lesions. These may vary from benign, nonspecific findings on MRI to vascular malformations or neurologic abnormalities. I evaluate all children who come to me with Parry Romberg syndrome with an MRI in order to see whether such abnormalities are present. Some children with Parry Romberg may have learning disabilities. Although some physicians dismiss this as a coincidence, I have seen it so many times that I believe the association is real.
Some children with Parry Romberg syndrome have developed inflammation of the optic nerve (the nerve in the back of the eye that provides vision). This is rare but requires immediate treatment if it occurs. I have also cared for children with linear scleroderma en coup de sabre who developed uveitis (ocular inflammation). All children with these conditions should have periodic ophthalmologic evaluations.
The combination of cosmetic and neurologic abnormalities in children with Parry Romberg syndrome makes the prognosis for these children more guarded. Most do well with corrective surgery, as needed, provided it is done by plastic surgeons experienced in dealing with this condition. A sympathetic family and physician are important. Special efforts must be made to help these children deal with the social stresses that result from their obviously abnormal appearance.
This article is an excerpt from Dr. Lehman’s book It’s Not Just Growing Pains: A Guide to Childhood Muscle, Bone, and Joint Pain, Rheumatic Diseases, and the Latest Treatments, published by Oxford Press and available at all major bookstores, including Amazon.com. Bracketed comments have been added for descriptive purposes by the editor of HSS.edu.