Pemphigus in Pediatric Population

Overview

Pemphigus represents a group of potentially life-threatening autoimmune blistering disorders characterized by intraepidermal blistering due to acantholysis. While rare in children, early recognition is crucial for optimal outcomes.

Key Points

• Incidence: 0.1-0.5 cases per 100,000 population per year
• Peak age: Uncommon in children, typically presents in adults (40-60 years)
• Gender distribution: Equal in children
• Genetic predisposition: HLA-DRw4, DRw14, and DQB1*0503

Pathophysiology

• Autoantibodies target desmoglein 1 and 3 (desmosomal proteins)
• Results in loss of keratinocyte adhesion (acantholysis)
• Forms intraepidermal blisters

Clinical Manifestations

Common Presentations

• Flaccid bullae on normal-appearing skin
• Painful erosions and crusting
• Nikolsky sign positive
• Mucosal involvement common (oral cavity)

Types of Pediatric Pemphigus

1. Pemphigus Vulgaris (PV)
   • Most common form
   • Begins with oral lesions in 50-70% cases
   • Cutaneous lesions follow weeks to months later
2. Pemphigus Foliaceus (PF)
   • Superficial blisters
   • No mucosal involvement
   • Better prognosis than PV

Diagnostic Approach

Clinical Evaluation

• Detailed history including:
  • Onset and progression
  • Family history
  • Associated symptoms
  • Previous treatments
• Complete physical examination
• Assessment of extent of involvement

Laboratory Studies

• Histopathology
  • Intraepidermal acantholysis
  • Suprabasal split in PV
  • Subcorneal split in PF
• Direct Immunofluorescence
  • IgG deposits in intercellular spaces
  • "Fishnet" pattern characteristic
• Indirect Immunofluorescence
  • Circulating anti-desmoglein antibodies
  • Titer correlates with disease activity
• ELISA
  • Anti-Dsg1 and Anti-Dsg3 antibodies
  • Useful for monitoring disease activity

Treatment Protocol

Initial Management

• Systemic corticosteroids (first-line)
  • Prednisolone 1-2 mg/kg/day
  • Gradual tapering based on response
• Adjuvant immunosuppressive therapy
  • Azathioprine (2-3 mg/kg/day)
  • Mycophenolate mofetil
  • Cyclophosphamide in severe cases

Advanced Therapies

• Rituximab
  • 375 mg/m² weekly for 4 weeks
  • Particularly effective in refractory cases
• IVIG in severe or resistant cases

Supportive Care

• Wound care and prevention of secondary infections
• Nutritional support
• Pain management
• Psychological support

Monitoring

• Regular assessment of disease activity
• Monitoring for adverse effects of medications
• Serial antibody titers
• Growth monitoring in children