Pemphigus Vulgaris
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
📖 About
- Pemphigus Vulgaris is a rare, chronic autoimmune blistering disease affecting skin + mucous membranes.
- Characterised by flaccid (easily ruptured) blisters and painful erosions, often starting in the mouth 👄.
- Untreated → high morbidity due to infection, fluid loss, malnutrition.
- Think of the "S" triad: Superficial (intraepidermal), Serious (life-threatening), Steroids (mainstay of treatment). ⚠️
🧬 Aetiology & Pathophysiology
- Caused by IgG autoantibodies against desmoglein 3 (mucosal) and sometimes desmoglein 1 (skin), key adhesion proteins in desmosomes.
- Loss of keratinocyte adhesion (acantholysis) → fragile intraepidermal blisters.
- Triggers: genetic predisposition (HLA-DR4, HLA-DQ1), drugs (e.g., Captopril, Penicillamine, thiol compounds).
- Without treatment → widespread blistering, infection, dehydration, and death 💀.
👀 Clinical Features
- Usually affects middle-aged/older adults (40–60 yrs), no gender bias.
- 💡 Often starts with painful oral ulcers → spreads to skin.
- Skin blisters: flaccid, fragile, easily rupture → raw erosions & crusting.
- Extensive mucosal involvement (oral, oesophageal, genital) common.
- Nikolsky sign +ve: lateral pressure causes epidermal detachment.
- Symptoms: painful erosions → difficulty eating, speaking, swallowing.
🔎 Differential Diagnosis of Blistering Diseases
- Pemphigus Vulgaris – intraepidermal, fragile blisters, mucosal + skin involvement.
- Bullous Pemphigoid – subepidermal, tense blisters, elderly, less mucosal disease.
- Porphyria Cutanea Tarda – photosensitive blisters, liver disease link.
- Dermatitis Herpetiformis – intensely itchy vesicles, gluten sensitivity.
- Erythema Multiforme – target lesions, infection/drug-triggered.
- Toxic Epidermal Necrolysis (TEN) – drug-triggered, widespread epidermal detachment, life-threatening 🚨.
⚠️ Complications
- Infections → secondary bacterial sepsis risk.
- Fluid/electrolyte loss → dehydration, shock.
- Malnutrition due to painful oral lesions → weight loss.
- Treatment-related: steroid side effects (osteoporosis, diabetes, infections).
💊 Management
- High-dose systemic corticosteroids = mainstay (often IV initially).
- Steroid-sparing immunosuppressants: azathioprine, mycophenolate mofetil, rituximab (anti-CD20, highly effective).
- Refractory cases: IVIG, plasmapheresis (to remove circulating antibodies).
- Supportive: meticulous wound care, emollients, antibiotics if infection, nutritional support.
- Multidisciplinary care 👥: dermatology, immunology, rheumatology, dietetics.
✅ Key Exam Pearls
- Autoantibodies vs desmoglein 3 (±1) → acantholysis.
- Flaccid blisters + mucosal involvement = hallmark.
- Nikolsky sign +ve.
- Treated with steroids ± immunosuppressants.
