Acute generalized exanthematous pustulosis

Background

• T-cell mediated rash with systemic features
• >90% of cases attributable to a medication (usually an antibiotic)
• Mortality rate of ~5%

Clinical Features

Acute generalized exanthematous pustulosis

• Onset 1-5 days after starting causative medication
• Rash:
  • Large areas of edematous erythema with numerous small, non-follicular pustules
  • Predominantly affects main body folds and upper trunk, but can involve face
  • NO mucous membrane involvement (in contrast to SJS/TEN)
• Systemic findings:
  • Fever
  • Leukocytosis, specifically neutrophilia
  • +/- Facial swelling
  • +/- Hepatitis
  • +/- Eosinophilia

Differential Diagnosis

• Erythema Multiforme
• Drug rash

Erythematous rash

• Positive Nikolsky’s sign
  • Febrile
    • Staphylococcal scalded skin syndrome (children)
    • Toxic epidermal necrolysis/SJS (adults)
  • Afebrile
    • Toxic epidermal necrolysis
• Negative Nikolsky’s sign
  • Febrile
    • Toxic shock syndrome
    • Kawasaki disease
    • Scarlet fever
    • DRESS syndrome
    • Cellulitis
    • Acute generalized exanthematous pustulosis
  • Afebrile
    • Alcohol intoxication
    • Anaphylaxis
    • Cellulitis
    • Dermatitis (multiple types)
    • Drug rash
    • Erysipelas
    • Erythema multiforme
    • Exfoliative erythroderma
    • Scombroid
    • Vancomycin infusion reaction

Evaluation

• Clinical diagnosis
• CBC
• BMP
• LFTs

Management

• Stop inciting agent
• IVF- treat similar to fluid resuscitation in burns
• Wound care, infection control

Disposition

• Admit

See Also

• Erythematous rash
• Stevens-Johnson syndrome and toxic epidermal necrolysis
• DRESS syndrome