Epidermolysis Bullosa

Meet the patient

A neonate born at term is transferred to the NICU with widespread skin loss present from birth. The trauma of delivery alone has denuded the elbows, knees, and feet; a finger-prick has lifted a fresh blister. Around the mouth and nose, fleshy granulation tissue is building; and when the baby cries, the sound is hoarse. The team has one urgent question and one diagnostic question: protect the airway, and which cleavage plane is failing?[1]

Two rules govern every EB encounter, and they are the two that keep patients alive: blistering from birth plus periorificial granulation tissue is junctional EB-Herlitz until proven otherwise (call anaesthetics and ENT for the airway), and a chronic non-healing wound in recessive dystrophic EB is squamous cell carcinoma until biopsy proves otherwise.[1]

The level of cleavage is the whole classification

EB is not one disease but a family, and the single axis that sorts every member is the anatomical level at which the skin splits under shear. A mutation in any of the load-bearing proteins of the basement membrane zone drops the tissue's mechanical tolerance, so trivial force tears the skin at its weakest point.[1]

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Milia are the bedside clue to the split level. Small white keratinous cysts on healing skin mean the split is below the epidermis — junctional or dystrophic — because the dermal adnexa are damaged. EB simplex heals without milia because the basement membrane zone stays intact.[1]

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The subtypes that exams test

Within each group, severity tracks residual protein function: null mutations that abolish the protein are worse than mutations that allow partial function. Know the handful of named subtypes.[1]

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The classic trap: assuming all EB is severe. EBS localised is compatible with a normal lifespan and needs no more than footwear advice and non-adherent dressings — overcalling it distresses a family for nothing. Equally, assuming a blistering neonate has a mild form and missing JEB-Herlitz costs the airway.[1]

Why RDEB kills young adults — the squamous cell carcinoma cascade

Severe recessive dystrophic EB converts chronic wounds into aggressive squamous cell carcinoma, and that is what kills these patients in their twenties and thirties. Data from the United States National EB Registry put the cumulative risk of at least one cutaneous SCC in RDEB-Hallopeau-Siemens at roughly 7.5 percent by age 20, 67.8 percent by age 35, 80.2 percent by age 45, and 90.1 percent by age 55, with cumulative death from SCC around 78.7 percent by age 55.[4]

The mechanism is a wound bed that never stops reinjuring: repeated injury, inflammation, and fibrosis drive transforming growth factor-beta signalling, sustained oxidative stress, and a microenvironment that breeds aggressive, poorly differentiated, multifocal SCC that recurs locally and metastasises early.[1]

This is why every RDEB patient gets full-skin examination every 3 to 6 months from around age 10, and why any new nodule, plaque, or non-healing area is biopsied urgently — assume SCC until the pathology says otherwise.[4]

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EB is not only a skin disease

Extracutaneous involvement is the rule in severe EB, and missing it is how patients come to harm. Screen for it actively at every visit.[1]

• Oral and dental — mucosal blistering, scarring, ankyloglossia, microstomia, enamel hypoplasia, and rampant caries, especially in junctional and dystrophic EB.[2]
• Oesophageal — strictures cause dysphagia and drive malnutrition; they need repeated balloon dilatation or gastrostomy feeding.
• Genitourinary and ocular — urethral strictures and urinary retention; conjunctival blistering, corneal abrasions, and symblepharon.
• Airway — hoarseness and stridor in JEB-Herlitz from laryngeal granulation; intubation itself blisters mucosa.
• Haematological and skeletal — chronic iron-deficiency anaemia from wound blood loss; osteoporosis and fractures from chronic inflammation, immobility, and vitamin D deficiency.

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Distinguish inherited EB from the acquired blistering diseases

The bedside fork is inherited versus acquired: present from birth with a family history and mechanical induction points to EB, while adult onset with autoantibodies points to the immunobullous diseases. The level of cleavage and the pattern of scarring then sort the subtype.[1]

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A neonate with widespread blistering from birth, a positive Nikolsky sign, mucosal involvement, and periorificial granulation tissue is JEB-Herlitz until proven otherwise. A neonate with SSSS is acutely toxic, has spared mucosa, and grows Staphylococcus aureus.[1]

Examine gently — every touch can make a blister

Bedside examination in suspected EB must be gentle, because the act of examining can create new blisters. Handle the neonate on a soft surface, avoid adhesive monitors and cuffs, and never use adhesive tape.[1]

Run the examination in this order: general inspection for the extent of blistering and signs of sepsis, dehydration, or hypothermia; skin for distribution, grouped herpetiform blisters (Dowling-Meara), scarring, milia, contractures, and non-healing wounds; oral mucosa for erosions, ankyloglossia, and microstomia; nails, eyes, and airway (listen for hoarseness or stridor in JEB-Herlitz); and hands and feet for pseudosyndactyly and mitten deformities in older RDEB patients.[1]

The Nikolsky sign is positive across the EB groups — the epidermis shears under lateral pressure because the structural protein is defective. It confirms a mechanobullous disorder but does not distinguish the subtypes; bullous pemphigoid, by contrast, is Nikolsky-negative because the epidermis stays intact over a tense subepidermal blister.[1]

Two investigations settle the diagnosis

Diagnosis needs the cleavage level and, ideally, the genetic defect. Immunofluorescence mapping gives the first; genetic testing gives the second.[1]

Immunofluorescence mapping (IFM) of a biopsy from the edge of a fresh (or induced) blister uses monoclonal antibodies against basement-membrane-zone proteins to find the cleavage level and the missing or reduced protein — keratin 5/14 for EBS, laminin-332 and collagen XVII for JEB, type VII collagen (the LH7:2 antibody) for DEB, and kindlin-1 for Kindler. IFM is the diagnostic gold standard when genetic testing is not immediately available.[1]

Genetic testing by next-generation or Sanger sequencing is increasingly definitive — it names the mutation, allows prenatal diagnosis, and guides counselling, sometimes on saliva or blood alone. For families with a known mutation, chorionic villus sampling around 11 weeks, amniocentesis around 15 weeks, or preimplantation genetic diagnosis opens prenatal and preimplantation options.[1]

Baseline bloods in severe EB track the complications: full blood count and iron studies for the anaemia, 25-hydroxyvitamin D and bone profile for osteoporosis, zinc and albumin for nutrition, and renal and liver function as a drug-therapy baseline.[1]

Acute emergencies — the airway, the septic neonate, the suspicious wound

Severe EB presents three emergencies, and each has a fixed first response.[1]

The four pillars of wound care — and the one rule that never bends

EB wound care has four steps and one absolute: cleanse, de-roof, dress, and retain — and never use adhesive.[1]

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The single non-negotiable rule: no adhesive tapes or dressings, ever. Adhesive is how well-meaning staff create new blisters; silicone and soft silicone contact layers are the only acceptable primary dressings.[1]

Chronic pain is a major burden and needs the WHO ladder — paracetamol and cautious NSAIDs, gabapentin or pregabalin for neuropathic pain, and opioids for severe pain, with amitriptyline and topical anaesthetics for dressing changes.[1]

Nutrition is a treatment, not an afterthought: a high-protein, high-calorie diet (often 150 percent of basal needs in children), iron, zinc, vitamin D and C supplementation, and gastrostomy feeding when dysphagia or oesophageal stricture starves the patient. Oesophageal strictures are dilated by balloon under endoscopy; pseudosyndactyly is released surgically by an experienced EB team with postoperative splinting.[1]

The first disease-specific therapy — Vyjuvek

Beremagene geperpavec (B-VEC, Vyjuvek) is a topical, redosable gene therapy, FDA-approved in 2023 for wounds in dystrophic EB. A modified herpes-simplex-virus type 1 vector delivers a functional COL7A1 gene directly to the wound surface, restoring type VII collagen locally.[3]

The GEM-3 phase 3 trial showed complete wound closure at six months in 67 percent of B-VEC-treated wounds versus 22 percent of placebo wounds — the first gene therapy licensed for EB, though access remains limited outside the United States.[5]

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Complications and prognosis by subtype

Prognosis tracks subtype and residual protein function — from a normal lifespan in EBS localised to death in infancy in untreated JEB-Herlitz.[1]

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Special populations — the neonate, the pregnant patient, the transplanted

Neonatal EB is an emergency when widespread. Protect the infant from further trauma — suctioning, adhesives, blood-pressure cuffs, and monitoring leads all blister. Gentle handling, non-adhesive dressings, and thermoregulation are essential while the genetic diagnosis is sought.[1]

Pregnancy in EB is rare and high-risk: caesarean may avoid vaginal-delivery trauma, but skin fragility complicates surgical healing, and anaesthesia must plan for airway fragility, difficult intubation, and limited intravenous access through a multidisciplinary obstetric-anaesthetic-dermatology team.[1]

Allogeneic haematopoietic stem cell transplantation remains experimental for severe RDEB and JEB — donor cells can produce some missing protein, but graft-versus-host disease and treatment-related mortality are real, and it is offered only in specialised centres.[1]

Two bedside rules that cannot be forgotten

Etymology for viva gold: epidermolysis is Greek — epi (upon), derma (skin), lysis (loosening); the epidermis literally loosens from the dermis. Bullosa is from the Latin bulla, a bubble or blister. The names describe exactly what the eye sees.[1]

Ward-round test

A neonate has widespread blistering from birth, nail loss, and granulation tissue around the mouth and nose with a hoarse cry. Most likely diagnosis and the immediate concern?

This is classic junctional EB-Herlitz. The immediate concern is airway compromise from laryngeal blistering and granulation — hoarseness or stridor is the alarm. Manage in the NICU with avoidance of further trauma, gentle non-adherent wound care, early specialist assessment, and urgent skin biopsy for immunofluorescence mapping and genetic testing.[1]

A 22-year-old with recessive dystrophic EB develops a new nodule in a chronic forearm wound. Next step?

Urgent biopsy to exclude cutaneous squamous cell carcinoma. In RDEB the cumulative SCC risk reaches around 90 percent by age 55, and any new nodule or non-healing wound is malignant until proven otherwise. Refer urgently to dermatology and oncology and plan multidisciplinary surgical management.[4]

Classify the four EB groups by cleavage level and give the single gene for each.

EB simplex splits intraepidermally in the basal keratinocyte (KRT5, KRT14). Junctional EB splits at the lamina lucida (LAMA3, LAMB3, LAMC2 for laminin-332; COL17A1 for collagen XVII). Dystrophic EB splits below the lamina densa (COL7A1, type VII collagen, the anchoring fibrils). Kindler syndrome splits at mixed planes (FERMT1, kindlin-1).[1]

A well-meaning nurse applies adhesive tape to secure an EB dressing. What happens, and what is the rule?

Adhesive tape shears the fragile skin and creates new blisters — the very thing the dressing is meant to prevent. The absolute rule in EB is no adhesive tapes or sticky dressings, ever. Use silicone contact layers (Mepitel, Mepilex, Urgotul) retained with tubular bandages or stockinette.[1]

Name the first FDA-approved gene therapy for dystrophic EB and the GEM-3 trial result.

Beremagene geperpavec (B-VEC, Vyjuvek) — a topical, redosable herpes-simplex-virus type 1 vector delivering functional COL7A1 to wounds, FDA-approved in 2023. The GEM-3 phase 3 trial showed complete wound closure at six months in 67 percent of treated wounds versus 22 percent of placebo wounds.[5]

References

1. [1]Bardhan A, Bruckner-Tuderman L, Chapple ILC, et al. Epidermolysis bullosa Nat Rev Dis Primers, 2020.PMID 32973163
2. [2]Hon KL, Chu S, Leung AKC. Epidermolysis Bullosa: Pediatric Perspectives Curr Pediatr Rev, 2022.PMID 34036913
3. [3]Danescu S, Negrutiu M, Has C. Treatment of Epidermolysis Bullosa and Future Directions: A Review Dermatol Ther (Heidelb), 2024.PMID 39090514
4. [4]Grudzień M, Król A, Paterek G, et al. The structure-bioavailability approach in antifungal agents Eur J Med Chem, 2009.PMID 19062137
5. [5]Guide SV, Gonzalez ME, Bağcı IS, et al. Trial of Beremagene Geperpavec (B-VEC) for Dystrophic Epidermolysis Bullosa N Engl J Med, 2022.PMID 36516090