SNOWMASS, COLO. — Physicians diagnosing epidermolysis bullosa in a newborn have few initial clues about which type of the disease their patient has, or the course it will take, until they do electron microscopy and immunofluorescence testing, according to Anne Lucky, M.D.
“At the very beginning the different forms of epidermolysis bullosa (EB) all look virtually the same. We tell parents we don't know if it's going to be a severe or mild form until the testing is done.” In other words, the child may have a normal lifespan or may die in the first year of life, she told this newspaper.
Speaking at a clinical dermatology seminar sponsored by Medicis, Dr. Lucky, professor of dermatology and pediatrics at the University of Cincinnati and the Cincinnati Children's Hospital Medical Center said that electron microscopy, immunofluorescence mapping of the basement membrane, and genetic investigation for specific proteins, can help distinguish between epidermolysis bullosasimplex (EBS), junctional epidermolysis bullosa (JEB), and dystrophic epidermolysis bullosa (DEB).
EBS is caused by keratin and plectin mutations, while JEB is caused by mutations of basement membrane proteins, and DEB is caused by mutations of type VII collagen, she explained.
Although all forms of EB cause severe blistering and skin erosions, blister formation in EBS is within the epidermis, while it is seen within the basement membrane zone in JEB, and within the upper dermis in DEB.
Correct identification of the type of EB is important for giving parents a realistic outlook about the prognosis, she explained. While all types of EB have variations in severity, certain subtypes of JEB (Herlitz) probably carry the worst prognosis, often associated with pyloric atresia, as well as severe, generalized granulation tissue around the trachea. Forms of DEB can be accompanied by esophageal strictures, as well pseudosyndactyly, and an increased risk for squamous cell carcinoma, among other things, she said.
Wound care plays an essential role in the management of all types of EB.
“Extensive aplasia cutis is usually fatal in the first weeks of life. It is really like handling a burn patient—they are very susceptible to infection,” she said, adding that new silicone-based bandages (manufactured by Mölnlycke) have made great improvements because they minimize skin trauma.
“They stick well to the surface of the skin, but with no adhesive—it's more like a suction,” said Dr. Lucky, who has no financial association with any company that makes products for treatment of EB.
In addition, biologically active dressings and grafts, such as Apligraf, a semi-permeable living skin graft, not only cover the wound, but promote healing. Wrapping is also important for protection and for avoidance of progressive syndactyly or fusion of digits as a result of extensive erosions.
Although esophageal strictures are common in certain forms of EB, Dr. Lucky says routine investigation for them is not necessary. If symptoms are present, barium swallows must start above the clavicle otherwise the stricture will generally be missed, she added. When indicated, esophageal dilation can be performed with hydrostatic balloon insertion and dilation, and the effects of this procedure can be expected to persist for at least 1 year.
Esophageal strictures and a gradual reduction in a child's ability to fully open his or her mouth can lead to poor nutrition, osteopenia, and dental problems. For these reasons, feeding gastrostomies should be considered, and prophylactic dental hygiene should be stressed, she said.
Hand surgery to separate webbed fingers is also an “untapped area,” she said. “Some surgeons do it, but with variable success. The future may lie in physical and occupational therapy.”
Pain management and psychiatric support are also important—and often go hand-in-hand because of the potential for drug addiction.
Dr. Lucky said many physicians have never heard of EB, and their first encounter may be overwhelming. The Cincinnati Children's Hospital Medical Center has an interdisciplinary EB team offering a full range of resources (www.cincinnatichildrens.org/eb-center
“Pseudosyndactyly” can occur in epidermolysis bullosa. This 4-year-old patient has a moderate case.
Wrapping is important for protection and for avoidance of fusion of digits as a result of extensive erosions. Photos courtesy Dr. Anne Lucky