Drug reaction with eosinophilia and systemic symptoms

Background

Characterized by fever, facial edema, maculopapular rash, lymphadenopathy, eosinophilia, atypical lymphocytosis, and multiorgan dysfunction
- Includes hepatitis, glomerulonephritis, arthritis, pneumonitis, and carditis
Typical onset 2 to 8 weeks after starting medication
Commonly-associated medications:
- Antibiotics, including vancomycin
  - Vancomycin-associated DRESS is more common in European descendants, with the HLA-A*32:01 allele
- Antiepileptic medications
- Allopurinol
High mortality around 10%

Criterion	-1	0	1	2	Notes
Fever ≥38.5ºC	No/U	Yes
Enlarged lymph nodes		No/U	Yes		>1 cm in ≥2 areas
Eosinophilia
—Eosinophils (if WBC ≥4), or			0.7-1.49	≥1.5
—Eosinophils (if WBC <4)			10-19.9%	≥20%
Atypical lymphocytes		No/U	Yes
Rash
—Skin rash (%BSA)		No/U	>50%
—Skin rash suggesting DRESS	No	U	Yes		≥2 of: purpuric lesions (other than legs), infiltration, facial edema, psoriasiform desquamation
—Biopsy suggesting DRESS	No	Yes/U
Organ involvement
—Liver involvement		No/U	Yes		Maximum score of 2
—Kidney involvement		No/U	Yes
—Muscle or heart involvement		No/U	Yes
—Pancreas involvement		No/U	Yes
—Other organ involvement		No/U	Yes
Resolution ≥15 days	No/U	Yes
Exclusion of other causes			Yes		at least 3 tests were done and negative: HAV, HBV, HCV, ANA, blood cultures, Mycoplasma, Chlamydia