Related Subjects:
|Nikolsky's sign
|Koebner phenomenon
|Erythema Multiforme
|Pyoderma gangrenosum
|Erythema Nodosum
|Dermatitis Herpetiformis
|Lichen Planus
|Acanthosis Nigricans
|Acne Rosacea
|Acne Vulgaris
|Alopecia
|Vitiligo
|Urticaria
|Basal Cell Carcinoma
|Malignant Melanoma
|Squamous Cell Carcinoma
|Mycosis Fungoides (Sezary Syndrome)
|Xeroderma pigmentosum
|Bullous Pemphigoid
|Pemphigus Vulgaris
|Seborrheic Dermatitis
|Pityriasis/Tinea versicolor infections
|Pityriasis rosea
|Scabies
|Dermatomyositis
|Toxic Epidermal Necrolysis
|Stevens-Johnson Syndrome
|Atopic Eczema/Atopic Dermatitis
|Psoriasis
⚡ Bullous Pemphigoid is a chronic autoimmune subepidermal blistering disorder, predominantly affecting the elderly.
Unlike Pemphigus vulgaris, mucosal involvement is uncommon, and blisters are tense rather than fragile.
Prompt recognition is essential due to the morbidity associated with extensive blistering and steroid therapy.
📖 Overview
- Autoimmune blistering disease characterised by large, tense bullae on erythematous or normal-appearing skin.
- Incidence: ~7–13 cases per million annually, typically ≥60 years (peak 70–80 years).
- Blister formation occurs due to separation at the dermo-epidermal junction, producing subepidermal bullae.
🧬 Pathophysiology
- Autoantibodies target hemidesmosomal proteins: BP180 (type XVII collagen) and BP230, critical for dermo-epidermal adhesion.
- Binding activates complement (C3) → recruits eosinophils and neutrophils → protease release → subepidermal cleavage and blister formation.
- The inflammatory cascade explains the characteristic pruritus often preceding blisters.
- Drug triggers: furosemide, penicillamine, certain antibiotics, and gliptins (DPP-4 inhibitors).
- Other associations: neurological disorders (stroke, Parkinson’s), malignancy (rare).
👩⚕️ Clinical Features
- Age: Usually elderly ≥60 years
- Blisters: Tense, subepidermal, less fragile than pemphigus vulgaris
- Mucosal involvement: Rare (<10%)
- Distribution: Flexural areas, trunk, limbs; pruritus often precedes lesions
- Prodrome: Urticarial or eczematous rash may appear weeks before blisters
🔎 Investigations
- Skin biopsy: Subepidermal blister with eosinophil-rich infiltrate
- Direct Immunofluorescence (DIF): Linear IgG and C3 deposition along the basement membrane zone
- Serology: ELISA for circulating autoantibodies against BP180 and BP230; correlates with disease activity
- Additional labs: Full blood count (eosinophilia), renal and liver function if systemic therapy anticipated
💊 Management
- Topical corticosteroids: High-potency clobetasol for limited disease; may be sufficient in elderly frail patients
- Systemic corticosteroids: Prednisolone for moderate to severe disease; taper guided by response
- Steroid-sparing immunosuppressants: Azathioprine, mycophenolate mofetil, or methotrexate for long-term control
- Adjunctive measures: Wound care, infection prevention, emollients
- Monitoring: Regular follow-up for disease activity, side effects (osteoporosis, diabetes, hypertension), and infection risk
📌 Key Clinical Differentiation
- Bullous pemphigoid: Elderly, tense subepidermal blisters, pruritus, rare mucosal involvement
- Pemphigus vulgaris: Middle-aged adults, fragile intraepidermal blisters, common mucosal involvement, higher risk of systemic complications
📚 Guideline References
