Diagnostic Criteria

DRESS*

1.     Fever ≥38.5°C (No: -1 points; Yes: 0 points)

2.     Lymphadenopathy (No: 0 points; Yes: 1 point)

3.     Eosinophilia (No: 0 points; 0.7-1.499x10⁹L^-1: 1 point;  ≥1.5x10⁹L^-1: 2 points)

4.     Atypical lymphocytes (No: 0 points; Yes: 1 point)

5.     Skin involvement (No: 0 points; >50%: 1 point)

6.     Organ involvement (No: 0 points; Yes: 1 point)

7.     Resolution ≥15 days (No: -1 points; Yes: 0 points)

8.     No other potential causes (1 point)

DIHS*

Typical DIHS requires all of the following 7 criteria (Atypical DIHS requires only the first 5):

1.     Maculopapular rash ≥ 3 weeks after initiating drug

2.     Symptoms present 2 weeks after stopping drug

3.     Fever ≥38.5°C

4.     Elevated liver enzymes

5.     Leukocyte abnormalities

6.     Lymph node enlargement

7.     Human Herpes Virus 6 reactivation

SJS*

*No universally accepted diagnostic  criteria, but clinical and histological findings include:

1.     Fever & malaise post drug exposure

2.     Erythematous macules progressing to vesicles/bullae

3.     Necrosis and sloughing of epidermis (<10% surface body area)

4.     Conjunctiva & mucous membrane involvement typical

5.     Biopsy findings: full thickness epidermal attachment with splitting & minimal inflammatory infiltrate