Introduction

• Rare inflammatory dermatosis characterized by:
  • Recurrent episodes of cellulitis-like plaques
  • Dense dermal eosinophilic infiltration
  • Absence of infection
• First described by George Wells in 1971
• Affects all age groups, including children
• No gender or racial predilection
• Often misdiagnosed as bacterial cellulitis

Clinical Features

1. Cutaneous Manifestations:

• Classic Presentation:
  • Acute onset of pruritic or burning erythematous plaques
  • Cellulitis-like appearance with edema
  • Bluish-grey central clearing ("slate-grey" appearance)
  • Annular or arcuate patterns
  • Commonly affects extremities, trunk, and face
• Clinical Variants:
  • Plaque type (most common)
  • Annular granuloma-like lesions
  • Bullous lesions
  • Papulonodular form
  • Fixed drug eruption-like presentation
• Disease Course:
  • Episodes last 2-8 weeks
  • Spontaneous resolution with residual hyperpigmentation
  • Recurrent nature with variable intervals

2. Associated Symptoms:

• General symptoms:
  • Low-grade fever
  • Arthralgia
  • Malaise
  • Pruritus
• Extracutaneous manifestations (rare):
  • Lymphadenopathy
  • Ocular involvement
  • Joint inflammation

Pathophysiology

1. Histological Features:

• Early Stage:
  • Edema of the dermis
  • Dense eosinophilic infiltration
  • Flame figures (hallmark finding)
• Late Stage:
  • Granulomatous inflammation
  • Histiocytic infiltration
  • Phagocytosis of eosinophilic debris

2. Immunological Mechanisms:

• Proposed mechanisms:
  • Type IV hypersensitivity reaction
  • Eosinophil dysfunction
  • Increased IL-5 production
  • Elevated eosinophil degranulation

3. Associated Conditions:

• Potential triggers:
  • Infections (bacterial, viral, parasitic)
  • Medications
  • Insect bites
  • Vaccinations
  • Myeloproliferative disorders
  • Atopic conditions

Diagnosis

1. Clinical Evaluation:

• Key Diagnostic Features:
  • Characteristic morphology and evolution of lesions
  • Recurrent nature
  • Absence of infectious etiology
  • Poor response to antibiotics

2. Laboratory Studies:

• Essential Tests:
  • Complete blood count with differential
  • Peripheral eosinophilia (>1500 cells/µL)
  • Elevated ESR and CRP
  • IgE levels
• Additional Studies:
  • Bacterial and fungal cultures
  • Parasitic investigations
  • Autoimmune markers

3. Histopathology:

• Skin Biopsy Findings:
  • Dermal edema
  • Eosinophilic infiltration
  • Flame figures
  • Granulomatous changes in late stages

4. Differential Diagnosis:

• Must consider:
  • Bacterial cellulitis
  • Erysipelas
  • Hypereosinophilic syndrome
  • Churg-Strauss syndrome
  • Allergic contact dermatitis
  • Arthropod bite reactions
  • Drug reactions

Management

1. First-Line Treatment:

• Systemic Corticosteroids:
  • Prednisolone 0.5-1.0 mg/kg/day
  • Gradual tapering over 2-4 weeks
  • Most effective in acute phase
• Topical Therapy:
  • High-potency topical corticosteroids
  • Tacrolimus ointment

2. Alternative Treatments:

• Steroid-Sparing Agents:
  • Antihistamines
  • Dapsone
  • Cyclosporine
  • Minocycline
  • Colchicine
  • IVIG (in refractory cases)

3. Prevention:

• Identify and avoid triggers
• Regular monitoring for:
  • Disease recurrence
  • Treatment complications
  • Associated conditions

Special Considerations

1. Pediatric Aspects:

• Clinical Considerations:
  • May present with atypical features
  • Higher association with atopic conditions
  • Better overall prognosis
• Treatment Modifications:
  • Careful steroid dosing
  • Preference for topical treatments
  • Regular monitoring of growth and development

2. Monitoring and Follow-up:

• Regular Assessment:
  • Disease activity
  • Treatment response
  • Complications
  • Associated conditions
• Long-term Outcomes:
  • Generally good prognosis
  • Variable recurrence rates
  • Rare chronic cases