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
- 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
Erythematous rash
- Positive Nikolsky’s sign
- Febrile
- Staphylococcal scalded skin syndrome (children)
- Toxic epidermal necrolysis/SJS (adults)
- Afebrile
- Febrile
- Negative Nikolsky’s sign
- Febrile
- Afebrile
Evaluation
Workup
- Clinical diagnosis
- CBC
- BMP
- LFTs
Diagnosis
Table of Severe Drug Rashes
Charateristic | DRESS | SJS/TEN | AGEP | Erythroderma |
Image | ||||
Onset of eruption | 2-6 weeks | 1-3 weeks | 48 hours | 1-3 weeks |
Duration of eruption (weeks) | Several | 1-3 | <1 | Several |
Fever | +++ | +++ | +++ | +++ |
Mucocutaneous features | Facial edema, morbilliform eruption, pustules, exfoliative dermattiis, tense bullae, possible target lesions | Bullae, atypical target lesions, mucocutaneous erosions | Facial edema, pustules, tense bullae, possible target lesions, possibl emucosal involvement | Erythematous plaques and edema affecting >90% of total skin surface with or without diffuse exfoliation |
Lymph node enlargement | +++ | - | + | + |
Neutrophils | Elevated | Decreased | Very elevated | Elevated |
Eosinophils | Very elevated | No change | Elevated | Elevated |
Atypical lymphocytes | + | - | - | + |
Hepatitis | +++ | ++ | ++ | - |
Other organ involvement | Interstitial nephritis, pneumonitis, myocarditis, and thydoiditis | Tubular nephritis and tracheobronical necrosis | Possible | Possible |
Histological pattern of skin | Perivascular lymphocytcic infiltrate | Epidermal necrosis | Subcorneal pustules | Nonspecific, unless reflecting Sezary syndrome or other lymphoma |
Lymph node histology | Lymphoid hyperplasia | - | - | No, unless reflecting Sezary syndrome or other malignancy |
Mortality (%) | 10 | 5-35 | 5 | 5-15 |
Management
- Stop inciting agent
- IVF- treat similar to fluid resuscitation in burns
- Wound care, infection control
Disposition
- Admit