Recessive Dystrophic Epidermolysis Bullosa (RDEB) is a rare and severe genetic skin disorder. It causes the skin to be extremely fragile, leading to blistering and tearing from friction or trauma. This condition results in chronic wounds that heal with significant scarring, impacting an individual’s quality of life.
Understanding Recessive Dystrophic Epidermolysis Bullosa
RDEB is a genetic disorder inherited in an autosomal recessive pattern. This means a child must inherit two copies of a mutated gene, one from each parent, to develop the condition. Parents who carry one copy of the mutated gene typically do not show symptoms themselves.
The specific gene involved in RDEB is COL7A1, located on chromosome 3. This gene provides instructions for producing type VII collagen, a protein essential for forming anchoring fibrils. Anchoring fibrils are structures that firmly attach the epidermis (the outermost layer of skin) to the underlying dermis (the layer beneath). A deficiency or malfunction of type VII collagen leads to poor adherence between these skin layers, causing them to separate and blister easily.
How RDEB Manifests
Wounds often heal with extensive scarring, which can include milial cysts and pseudosyndactyly, a fusion of fingers or toes that creates a “mitten” deformity. Scarring can also lead to contractures, limiting joint mobility. Beyond the skin, individuals with RDEB experience involvement of mucous membranes throughout the body.
Blistering and scarring frequently occur in the mouth, causing pain, difficulty eating, and dental issues like caries. The esophagus can also blister and scar, leading to strictures that make swallowing difficult and contribute to malnutrition. Eyes may experience corneal abrasions and scarring, potentially impairing vision.
Systemic complications are common. Anemia can develop due to chronic blood loss from wounds, and malnutrition often occurs from eating difficulties and increased metabolic demands. Musculoskeletal issues, such as joint contractures, severely restrict movement and independence. An increased risk of squamous cell carcinoma, a type of skin cancer, arises in chronic wounds.
Identifying RDEB
Diagnosis of RDEB often begins with clinical observation of characteristic blistering and skin fragility present at birth or shortly thereafter. Specific diagnostic tools are then used to confirm the condition.
A skin biopsy involves taking a small tissue sample for specialized laboratory analysis. Immunofluorescence mapping is performed on the biopsy, which helps determine the presence and location of type VII collagen within the skin layers. Transmission electron microscopy (TEM) can also be used to visualize the ultrastructural defects in anchoring fibrils. Genetic testing confirms the diagnosis by identifying specific mutations in the COL7A1 gene. Genetic counseling is important for affected individuals and their families to understand the inheritance pattern and implications for future family planning.
Managing RDEB
Managing RDEB requires a comprehensive, multidisciplinary approach focused on symptomatic relief, preventing complications, and improving quality of life, as there is currently no cure. Daily wound care involves meticulous cleaning of blisters and open wounds to prevent infection. Specialized non-adhesive dressings are applied to protect the fragile skin and promote healing. Infection prevention, including the careful use of antibiotics for secondary infections, are essential.
Pain management addresses chronic pain from wounds and medical procedures. This can involve topical anesthetics applied directly to painful areas and systemic analgesics for broader pain relief. Nutritional support is important due to oral blistering and increased metabolic demands. Soft diets, nutritional supplements, and feeding tubes are used to ensure adequate calorie and nutrient intake.
Maintaining mobility and preventing contractures are addressed through physical therapy. Interventions focus on maintaining range of motion and strengthening muscles, often incorporating assistive devices to aid mobility.
Surgical interventions may be necessary to address specific complications like esophageal strictures, which can be dilated to improve swallowing. Pseudosyndactyly can also be surgically corrected to improve hand function. Skin grafting may be considered for non-healing wounds.
Psychological support is important, acknowledging the emotional burden on patients and their families. Counseling and support groups provide resources. Regular monitoring for squamous cell carcinoma is performed due to the increased risk in RDEB patients.