Epidermolysis Bullosa: Classification, Risks, and Care

Epidermolysis bullosa (EB) is a group of rare genetic skin disorders in which the skin blisters and tears from friction or minor trauma that would not affect healthy skin. The underlying problem is a missing or defective structural protein somewhere in the layers that hold skin together, and which protein is affected determines everything from how severe the blistering is to whether internal organs are involved. EB is not one disease but a family of conditions, and the range of severity spans from mild blistering on the hands and feet to a life-threatening multisystem illness.

How EB Is Classified

EB is divided into four major types based on where in the skin the splitting occurs. In epidermolysis bullosa simplex (EBS), the separation happens within the outermost layer of the skin itself. In junctional EB (JEB), it occurs at the junction between the outer and inner layers. In dystrophic EB (DEB), the split is even deeper, below the basement membrane in the upper dermis. A fourth category, Kindler syndrome, involves mixed-level blistering that can occur at more than one of these planes. An internationally recognized classification system layers additional detail on top of these four types, incorporating the severity, whether the condition is inherited from one or both parents, and which specific protein and genetic variant are involved.¹

Within each type, there is a wide spectrum. Some people with EBS develop blisters mainly on their palms and soles during warm weather. Others with severe recessive dystrophic EB (RDEB) face chronic wounds over much of their body from infancy onward. Describing someone as having “epidermolysis bullosa” without specifying the type says almost nothing about their prognosis, which is part of why the condition is so often misunderstood.

Which Proteins Are Involved

Each EB type traces back to defects in different structural proteins that normally anchor the skin’s layers to one another. In EBS, the problem sits in keratin 5 and keratin 14, proteins that form the internal scaffolding of cells in the bottom layer of the epidermis. When these keratins are faulty, the cells collapse under mechanical stress and blister.² Research using atomic force microscopy has shown that certain keratin 14 mutations make cells even less resistant to deformation than cells with no keratin at all, meaning the mutated protein actively worsens structural integrity rather than simply being absent.³

In junctional EB, the culprit is usually laminin 332, a protein complex made of three chains encoded by the LAMA3, LAMB3, and LAMC2 genes. Laminin 332 is a major component of the anchoring filaments that glue the epidermis to the dermis. When it is absent or dysfunctional, that bond fails.⁴ The most severe form, sometimes called Herlitz JEB, involves a complete loss of laminin 332 and is often fatal in infancy.⁵

Dystrophic EB results from mutations in the COL7A1 gene, which encodes type VII collagen. This collagen forms the anchoring fibrils that secure the basement membrane to the deeper dermis. Without functional type VII collagen, even mild friction causes blisters below the basement membrane, leading to wounds that heal with heavy scarring.⁶

More Than a Skin Disease

One of the most common misconceptions about EB is that it affects only the skin. In reality, the same fragile membranes line the mouth, throat, esophagus, and other internal surfaces. The gastrointestinal tract is frequently involved, and one of the most disabling complications is the development of esophageal strictures, where repeated blistering and scarring narrows the esophagus. This leads to progressive difficulty swallowing, which in turn contributes to malnutrition, chronic anemia, and growth delays in children.⁷ Endoscopic dilation can relieve these strictures. In one study, most patients showed improvements in swallowing after the procedure, with a mean weight gain of about 3 kg within a month and no significant complications from the dilation itself.⁸

The nutritional burden goes beyond swallowing difficulties. Children with EB have elevated energy needs because the body is constantly working to heal wounds and fight infection. At the same time, mouth and throat blisters make eating painful, and gut involvement can impair nutrient absorption.⁹ A study evaluating laboratory markers in children with EB found that the majority had some degree of anemia, with roughly a third showing moderate anemia. Vitamin B12 deficiency was common, and the severity of nutritional problems tracked closely with disease severity. Children who followed dietitian-guided plans did see significant improvements in weight and height.¹⁰

Scarring, Fibrosis, and Cancer Risk

In recessive dystrophic EB, the cycle of wounding and healing produces dense scar tissue that progressively transforms the skin. Fingers and toes can fuse together as scarring encases them in a mitten-like sheath, a process called pseudosyndactyly. Research has identified that a signaling molecule called TGF-β plays a central role in driving this runaway fibrosis. Fibroblasts in RDEB skin have an enhanced ability to activate TGF-β from its dormant form, and multiple activators work together in a self-reinforcing loop that keeps pushing the scarring forward.¹¹

The chronic wound environment in RDEB also creates a dangerously elevated risk of squamous cell carcinoma, an aggressive skin cancer that is the leading cause of death in adults with severe RDEB. A 28-year retrospective study found that these cancers appeared at a median age of about 30 in severe RDEB, decades earlier than in other EB subtypes. Among patients with severe RDEB, cancer-related mortality was about 65%, with a median survival of only about two and a half years after the first tumor was diagnosed. Many patients developed multiple tumors over their lifetimes.¹² Genomic analysis has pointed to a specific mutational signature driven by APOBEC enzymes as a contributor to these early-onset cancers, offering a potential target for future screening or intervention.¹³

Daily Wound Care and the Microbiome

For families living with EB, wound care dominates daily life. Bandage changes alone can take hours, and they are painful. A consensus approach to EB wound management recommends bathing in diluted bleach or applying diluted vinegar compresses to reduce bacterial load on the skin. Topical antibiotics should be rotated every two to six weeks to avoid building resistance, and clinicians recommend applying them to the dressing rather than directly onto the wound to minimize pain. Dressings containing silver, honey, or iodine are also used.¹⁴

Infection control is complicated by the fact that EB skin harbors a distinctly altered microbiome. In children with recessive dystrophic EB, the skin’s bacterial diversity drops significantly compared with healthy children, and Staphylococcus aureus becomes the dominant species early in life, first colonizing wounded skin and then spreading to unwounded areas. The abundance of S. aureus correlates with both acute and chronic wound burden and, to some extent, with markers of systemic inflammation.¹⁵ Wound dressings themselves can further shift the microbiome. One study found that the reduced bacterial diversity and increased staphylococcal carriage seen in EB wounds appeared specifically after topical treatment was applied, suggesting dressings may have direct or indirect effects on the wound ecology.¹⁶ These microbiome findings are still preliminary, but they hint at a future where wound care might be tailored not just to the wound itself but to its bacterial inhabitants.

Emerging Therapies

For decades, EB treatment was entirely about managing symptoms. That picture has started to change. In 2023, the FDA approved the first gene therapy for any form of EB: beremagene geperpavec (marketed as Vyjuvek), a topical treatment for dystrophic EB. It uses a modified herpes simplex virus to deliver working copies of the COL7A1 gene directly to wound cells, restoring production of type VII collagen at the application site.¹⁷ The treatment does not cure the underlying genetic condition throughout the body, but it offers a way to promote healing at individual wound sites, which for people who have lived with untreatable chronic wounds is a meaningful advance.

For the fibrosis and digit fusion that plague RDEB, the blood pressure drug losartan has shown early promise. In animal models, long-term losartan treatment reduced TGF-β signaling in chronically injured skin, halted fibrosis, and prevented digit fusion. It also lowered markers of inflammation.¹⁸ A small human trial in children with RDEB found that losartan was well tolerated and associated with improvements in clinical disease scores and quality of life. Notably, finger span between thumb and index finger increased by about 7 mm over nine months, suggesting some slowing or reversal of pseudosyndactyly.¹⁹ Losartan is already widely available and inexpensive, which makes it an especially attractive candidate if larger trials confirm the benefit.

Gene editing via CRISPR is also advancing for EB, though it remains at an earlier stage. Researchers have used CRISPR-Cas9 to selectively knock out a mutant copy of the KRT14 gene in epidermal stem cells taken from a patient with dominant EBS, achieving editing efficiency greater than 95% on the faulty gene while leaving the healthy copy untouched. The corrected cells restored a normal structural protein network and retained their stem cell properties, meaning they could theoretically regenerate functional skin.²⁰ Work is ongoing to extend similar gene-editing strategies to stem cells for wound-healing applications in other EB types.²¹

Prenatal Testing and Family Planning

Because EB is genetic, families with an affected child or a known carrier status often want to know the risk for future pregnancies. DNA-based prenatal testing is available and well established. For junctional EB, direct mutation detection from chorionic villus sampling or amniocentesis has been used successfully, with results validated by the birth of healthy children or confirmed by fetal skin biopsy when an affected fetus was predicted.²² A large study covering 144 consecutive at-risk pregnancies across multiple EB types reported a success rate above 98% for molecular prenatal diagnosis, making it a reliable option for families who want early information.²³

Modern genetic panels can now identify the specific mutation in most EB families, which opens the door to preimplantation genetic testing during IVF as well. The expanding availability of exome and genome sequencing also means that families with no prior history of EB who have a child diagnosed with a new (de novo) mutation can be counseled about recurrence risk based on the specific inheritance pattern and variant involved.

Pain, Psychological Burden, and Caregiver Impact

Pain in EB is constant and multifaceted. There is acute pain during bandage changes and bathing, and there is chronic background pain from wounds, scarring, and inflammation. Evidence-based guidelines for EB pain management recommend a range of psychological approaches alongside medication, including cognitive behavioral therapy, hypnosis, biofeedback, and relaxation training. These techniques have been shown to reduce pain intensity, lessen distress, decrease pain-related disability, and improve coping in both acute procedural settings and chronic pain conditions.²⁴

The burden extends heavily to caregivers. Parents of children with EB often spend hours each day on wound care, navigate complex medical appointments, and manage their child’s pain and emotional distress. Research has found that this caregiving load creates significant parental stress that adversely affects parents’ quality of life and mental health. Resilience, the ability to adapt and recover from adversity, appears to be a protective factor, and supporting parental resilience has been identified as a worthwhile target for psychosocial interventions in EB families.²⁵

The Acquired Form

Not all epidermolysis bullosa is inherited. Epidermolysis bullosa acquisita (EBA) is an autoimmune condition in which the body produces antibodies against its own type VII collagen, the same protein affected in dystrophic EB. The result is similar blistering and skin fragility, but it typically appears in adulthood rather than at birth and is driven by the immune system rather than a genetic mutation.²⁶ EBA is rare even among autoimmune blistering diseases, and it can be tricky to diagnose because it mimics other conditions. Treatment focuses on suppressing the immune response rather than replacing a missing protein, so the therapeutic approach is fundamentally different from inherited EB despite the similar clinical picture.

EB in Animals

Epidermolysis bullosa is not unique to humans. The condition has been documented in dogs, cats, horses, sheep, and other species, caused by mutations in the same structural protein genes. As in humans, animal EB is classified into simplex, junctional, and dystrophic forms based on the level of skin separation, and the clinical features, extreme skin fragility and blistering after minor trauma, are strikingly similar across species.²⁷ Animal cases have contributed to scientific understanding of EB biology and have served as natural models for testing treatments, including the losartan studies that eventually led to human trials. For veterinarians, recognizing EB in a puppy or foal with unexplained skin blistering matters because it changes the prognosis and breeding recommendations for the affected line.