Cath Lab Digest

T he term inherited epidermolysis bullosa (EB) refers to a group of rare genetic diseases characterized by the presence of extremely fragile skin and recurrent blister formation. Any trauma or minor friction to the skin or mucous membranes may result in blistering or tearing of the skin. It is estimated that one in every 50,000 live births is affected by some form of inherited EB.¹ The four major forms of EB are EB simplex (EBS), junctional EB (JEB), dominant dystrophic EB (DDEB), and recessive dystrophic EB (RDEB).

With EB simplex, blister formation occurs in the epidermis; with junctional EB, blisters form within the lamina lucida of the basement membrane zone (the dermal-epidermal junction); and with both recessive and dominant dystrophic EB, blisters originate in the uppermost part of the dermis, just beneath the lamina densa. Genetic mutations most commonly occur in Keratin 5 and 14 (EBS), Laminin-5 and Type XVII Collagen (JEB), and Collagen VII (DDEB and RDEB).²

Routine care of EB consists of meticulous daily skin and wound care. The recommended treatment includes a rigorous routine of inspecting the skin, lancing new blisters, and applying ointments and nonstick dressings. Researchers are working to develop gene transfer techniques, but the ultimate goal of a cure through gene therapy has not yet been realized. The primary objectives of care are to promote healing, prevent infection, prevent excessive loss of body fluid, and reduce pain.

Fine³ reported the findings of a study in which 425 patients with inherited EB were sampled to assess the presence of and possible differences in cutaneous pain scores. This study reported that fewer than 10% of individuals with RDEB and 12% to 13% of individuals with EBS, JEB, and DDEB say they are pain-free. Moderate to severe pain frequency was most often noted in patients with clinically more extensive disease involvement. This study demonstrates that cutaneous pain is the norm in all major types of EB - the alarming realization is that approximately 90% of individuals with EB report experiencing pain on an average day.

Although many medications on the market treat pain, they are not without significant side effects for the patient. Due to the chronicity of the disease and the prevalence of ongoing pain in this population, a reasonable goal is to determine alternatives to the use of pain medications, which include opioids. While opioids clearly provide pain relief, many of the side effects - constipation, pruritus, tolerance, and central nervous system (CNS) depression - actually may worsen the overall condition of EB.

Infants and young children with EB present an even greater treatment challenge. Medications causing CNS depression and sedation frequently result in feeding difficulties and weight loss in the infant. Feeding difficulties in infants with EB may cause a life-threatening downward spiral, as their fluid and protein requirements are already higher due to the presence of wounds and denuded areas. Inadequate nutrition slows wound healing, decreases immunocompetence, and increases susceptibility to infection.^4,5

Clearly, the cause of the pain cannot be eliminated. An attempt must be made to protect the skin from injury. This can be accomplished through gentle handling, applying lubricants to reduce friction, and using protective dressings that help prevent friction. Bandages are secured with rolled gauze and tubular retention dressings because using tape and adhesives causes further blistering and skin loss.