Msk Dermatology · Year 2 · from Msk Dermatology
Case 1: Epidermolysis Bullosa - Dermal-Epidermal Junction Disorder
Patient Presentation
Demographics: 2-day-old male neonate
Chief Complaint: Blistering and skin erosions noted at birth
History of Present Illness: The infant was born at term via vaginal delivery. At birth, the nursing staff noted several blisters and areas of skin loss on his hands, feet, and around his mouth. Minimal handling causes new blisters to form. The parents have no family history of similar skin conditions.
Physical Examination:
- General: Full-term neonate, appropriate size
- Skin:
- Multiple tense blisters on hands and feet
- Erosions at sites of previous blisters
- Perioral erosions (from sucking)
- New blister formation with gentle friction
- No infectious signs
Workup and Results
Skin Biopsy:
- Light microscopy: Subepidermal blister formation
- Immunofluorescence mapping: Separation at lamina lucida
- EM: Absent hemidesmosomes and anchoring filaments
Genetic Testing:
- Mutation in LAMA3 gene (laminin-332)
- Consistent with junctional epidermolysis bullosa
Clinical Image
Clinical photograph demonstrating tense blisters and erosions on the hand of an infant with epidermolysis bullosa, showing characteristic fragility at sites of friction.
Diagnosis
Junctional Epidermolysis Bullosa
Classification:
- Blister formation at the dermal-epidermal junction (lamina lucida)
- Due to mutations in components of the anchoring complex
Discussion
This case illustrates dermal-epidermal junction disorders:
- DEJ Components: The lecture describes the complex architecture of the dermal-epidermal junction, including hemidesmosomes, anchoring filaments (containing laminin-332), and anchoring fibrils (type VII collagen).
- Blistering from Junction Disruption: The lecture explains that disruption of the dermal-epidermal junction leads to blistering diseases. The level of separation (within epidermis, at DEJ, or in dermis) determines the type of blistering disorder.
- Type VII Collagen: The lecture notes that type VII collagen forms anchoring fibrils that connect the basement membrane to the dermis. Mutations or antibodies against type VII collagen cause dystrophic epidermolysis bullosa or epidermolysis bullosa acquisita, respectively.
- Mechanical Fragility: The DEJ is designed to withstand shearing forces. Defects in any component lead to mechanical fragility and blister formation with minimal trauma.
Treatment Plan
- Wound Care:
- Non-adherent dressings
- Gentle handling - "minimal touch" technique
- Protective padding at friction sites
- Nutrition:
- Monitor feeding (oral blisters can impair intake)
- May need soft nipples or alternative feeding methods
- Infection Prevention:
- Daily wound assessment
- Topical antibiotics if concerning for infection
- Low threshold for cultures
- Multidisciplinary Care:
- Dermatology, pediatrics, genetics, nutrition
- Physical/occupational therapy as child grows
- Genetic counseling for family
- Long-term Monitoring:
- Growth and development
- Screening for esophageal strictures
- SCC surveillance in dystrophic forms
Teaching Points
- The DEJ consists of hemidesmosomes, lamina lucida, lamina densa, and anchoring fibrils
- Type VII collagen forms anchoring fibrils connecting basement membrane to dermis
- DEJ disruption causes blistering diseases (mechanical fragility)
- Immunofluorescence mapping localizes the level of blister formation
- Different EB subtypes result from mutations in specific junction components