Makindo Medical Notes

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 primarily affecting the skin and mucous membranes.
• The condition is characterized by flaccid (easily ruptured) blisters and erosions on the skin, typically starting in the mouth.
• It is associated with significant morbidity if untreated, as the blisters can lead to secondary infections and fluid loss.
• Remember the "S" triad: Superficial (blisters are intraepidermal), Serious (can be life-threatening), and treated with Steroids (main treatment).

Aetiology

• The disease is caused by IgG autoantibodies directed against desmoglein 3 and, in some cases, desmoglein 1, which are proteins that maintain the adhesion between epidermal cells (keratinocytes).
• Loss of adhesion between keratinocytes (acantholysis) leads to the formation of intraepidermal blisters.
• Without treatment, pemphigus vulgaris can lead to widespread blistering, infection, dehydration, and potentially fatal complications.
• Potential triggers for the disease include genetic predisposition (HLA class II alleles) and the use of certain medications such as Captopril, Penicillamine, and other thiol-containing drugs.

Clinical Features

• Commonly seen in middle-aged and older adults, with no gender predilection (affects males and females equally).
• Blisters typically begin in the mucous membranes, especially the mouth, and may also involve the skin over time.
• The blisters are soft, flaccid, and rupture easily, leaving painful erosions or open sores.
• Mucosal involvement (e.g., oral ulcers, oesophageal, genital mucosa) can be extensive and precedes skin involvement in many cases.
• Because the blisters burst easily, they may be absent when the patient presents, leaving only red, raw erosions.
• Painful blistering, red weeping erosions, and crusting are common, leading to difficulty eating and speaking if oral involvement is present.
• Nikolsky sign is positive: gentle lateral pressure on intact skin causes epidermal detachment.

Differential Diagnosis of Blistering Diseases

• Pemphigus Vulgaris (superficial blisters, intraepidermal, autoimmune).
• Pemphigoid (blisters are deeper, subepidermal, less serious, more common in older adults).
• Porphyria cutanea tarda (photosensitive skin blisters, often associated with liver disease).
• Dermatitis herpetiformis (intensely itchy blisters, associated with gluten sensitivity).
• Erythema multiforme (target lesions, often following infections or medications).
• Toxic epidermal necrolysis (TEN) (life-threatening skin condition with widespread epidermal detachment, usually triggered by drugs).

Complications

• Infection: Secondary bacterial infection of the exposed erosions is common, which can lead to sepsis if not managed.
• Fluid and electrolyte imbalance: Loss of skin integrity can result in fluid loss, contributing to dehydration and electrolyte imbalances.
• Malnutrition: Severe oral involvement may cause pain and difficulty swallowing, leading to weight loss and malnutrition.
• Medication side effects: Long-term steroid use can cause complications such as diabetes, osteoporosis, and infections.

Management

• High-dose corticosteroids are the cornerstone of treatment to suppress the immune system and reduce inflammation.
• Other immunosuppressive agents like azathioprine, mycophenolate mofetil, or rituximab are often added to reduce the need for long-term steroids and to induce remission.
• For severe or refractory cases, intravenous immunoglobulin (IVIG) or plasmapheresis may be used to rapidly reduce circulating autoantibodies.
• Meticulous wound care is required to prevent infections in areas of blistering and erosion.
• Antibiotics may be necessary if secondary infections are suspected or confirmed.
• Patients should be monitored for complications of immunosuppressive therapy, including infection and long-term side effects of steroids (e.g., osteoporosis, hyperglycemia).
• A multidisciplinary approach involving dermatologists, immunologists, and possibly rheumatologists is often necessary to optimize patient care.