Diagnosis

Pemphigus vulgaris

Etiology

Cause [bci]

• The precise etiology is unknown

• Genetic risk (association with certain HLA alleles)

• Enviromental triggers:

  • Drugs: Penicilline, captopril, cephalosporin, pyrazolones, NSAIDs, thiols, rifampin

  • Emotional stress

  • Diet

  • Thermal burns

  • Ultraviolet rays

  • Virus (coxsackievirus, Herpesviridae family)

Pathophysiology [p7h][bci]

1. IgG autoantibodies directed against cell-adhesion molecules (desmogleins)

2. This causes keratinocytes to fall apart (acabtholysis) --> bullous dermatosis

Less common types of pemphigus [k9p]

• Familial Benign Pemphigus

• Linear IgA Dermatosis

• Pemphigus Erythematosus

• Pemphigus Foliaceus

• Pemphigus Herpetiformis

• Drug-Induced Pemphigus

• IgA Pemphigus

• Paraneoplastic Pemphigus

Complications [bci]

• Secondary infections (sepsis is the most common cause of death in PV)

• Other autoimmune diseases

• Malignancy

• Corticosteroid side effects: osteoporosis, hyperglycemia, insomnia, increased appetite, hypertension, edema, adrenal suppression, cataracts, and delayed wound healing

Epidemiology

Incidence per 100.000 [pyi][mce][y6b]

Approach

• Blood test: blood count, electrolytes, hepatic and renal function, glycemia and glycated hemoglobin, vitamin D, lipids, serology for hepatitis B and C, syphilis and HIV,

• Urine test; pregnancy

• Chest X-ray

• Bone densitometry

• Biopsy with immunofluorescence (accurate diagnosis)

• ELISA

Treatment

1. First line treatment: [p7h][bci][0i5]

   • Prednisone 40 to 100 mg/day depending on severity

   • If control is not achieved: Methylprednisolone (1 g/day IV) or dexamethasone (300 mg/day IV) pulse therapy

   • Rituximab anti-CD 20 antibody

2. Second line treatment: Steroid-sparing immunosuppressives (hypertension, diabetes mellitus, glaucoma, or osteoporosis)

   • Azathioprine 100-200 mg/day (1-3 mg/kg/day) orally, divided into two doses

   • Mycophenolate mofetil/sodium 2-3g/day, divided into two doses

3. Third line treatment:

   • Intravenous human immunoglobulin (IVIG) 0.4g/kg/day for five days

   • Plasmapheresis/immunoadsorption

   • Cyclophosphamide orally (1-3 mg/kg/day)

   • Dapsone 50-200mg/day

   • Methotrexate 10 to 20mg/week

   • Cyclosporine 3-5mg/kg/day

   • Anti-TNF-α

4. Antibiotics: if secondary infection, guided by culture of blood and skin samples

5. Topical treatment: Always adjuvant to systemic treatment

   • Corticosteroid creams

   • Tacrolimus

   • Antibiotic creams

   • Antiseptic solutions (potassium permanganate)

Differential diagnoses

Aphthous stomatitis, Behcet's disease, Bullous pemphigoid, Dermatitis herpetiformis, Ecthyma, Eczema, Epidermolysis bullosa, Erysipelas, Erythema multiforme, Herpes simplex, Herpes zoster, IgA Pemphigus, Impetigo, Lichen planus, Paraneoplastic pemphigus, Pemphigus erythematosus, Pemphigus foliaceus, Stevens-Johnson syndrome, Systemic lupus erythematosus