Drug reaction with eosinophilia and systemic symptoms

Background

• T-cell mediated hypersensitivity reaction

Clinical Manifestations

• 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%

DRESS Scoring System

• Developed for RegiSCAR, though I can't seem to find a primary reference

Criteria

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

Interpretation

Interpretation	Points
Definite	≥6
Probable	4-5
Possible	2-3
Not DRESS	≤1

Further Reading

• The DRESS Syndrome: A Literature Review. Am J Med. 2011;124(7):588-597. doi: 10.1016/j.amjmed.2011.01.017