II. Epidemiology
- Age of onset 60 to 80 years old
- Men and women affected equally
- Incidence: 7 per 1 million in U.S.
III. Pathophysiology
- Autoimmune Subepidermal Blistering
- Mediated by IgG auto-antibodies that target basement membrane hemidesmosome at dermal-epidermal junction
IV. Causes
- Idiopathic (85% of cases)
- Specific trigger (15% of cases)
- Radiation Therapy
- Burn Injury
- Immunization
- Surgery
- Trauma
- Medications (esp. Furosemide)
V. Symptoms
- Pruritus
- Lesions may be tender at borders
VI. Signs
- First phase (weeks to months)
- Second phase
- Develops into large tense bullae (1 to 4 cm in diameter) after weeks to months
- Contain clear fluid or may at times be hemorrhagic
- Form over an erythematous base
- Diffuse cutaneous involvement
- No scar formation
- Milia may form at previously involved sites
- Nikolsky Sign is absent (contrast with Pemphigus lesions)
- Thick walled bullae
- Develops into large tense bullae (1 to 4 cm in diameter) after weeks to months
VII. Labs
- Histology
- Subepidermal Blister
- Superficial dermal inflammation (Eosinophils)
- Immunofluorescence
- IgG and C3 deposition along basement membrane zone
VIII. Differential Diagnosis
- See Bullous Disease
IX. Management
- Goals
- Limit lesion spread
- Observe for opportunistic infection
- Decrease pain
- First-Line
- Prednisone 1 mg/kg/day
- Methotrexate may be used for Prednisone intolerance
- High potency Topical Corticosteroids in localized mild cases
- Adjunctive agents (Corticosteroid sparing)
X. Complications
- Secondary Skin Infection
XI. Course
- Self-limited condition
- Chronic in many cases with exacerbations and remissions
- Remits with treatment by 6 years in 50% of cases
XII. References
- Long (2016) Crit Dec Emerg Med 30(7):3-10
- Bickle (2002) Am Fam Physician 65:1861-70 [PubMed]
- Cotell (2000) Am J Emerg Med 18(3):288-99 [PubMed]
- Dillard (2023) Am Fam Physician 107(1): 85-6 [PubMed]