Algorithm of Drug Causality for Epidermal Necrolysis (ALDEN score)
Delay from initial drug component intake to onset of reaction (index day)
Drug started on or after the index day
1-4 days
1-4 days in case of previous reaction to the same drug
5-28 days
29-56 days
5-56 days in case of previous reaction to the same drug
> 56 days
Drug present in the body on the index day
Drug continued up to index day or stopped at a time point < 5× the elimination half-life before the index day
Drug stopped at a time point before the index day by > 5× the elimination half-life; liver or kidney function alterations or suspected drug interactions are present
Drug stopped at a time point before the index day by > 5× the elimination half-life; no liver or kidney function alterations or suspected drug interactions
Prechallenge/rechallenge
Stevens-Johnson syndrome/toxic epidermal necrolysis after using the same drug
Stevens-Johnson syndrome/toxic epidermal necrolysis after using a similar drug or other reaction with the same drug
Other reactions after using a similar drug
No known previous exposure to the drug
Exposure to the drug without any reaction (before or after reaction)
Dechallenge
Drug stopped (or unknown)
Drug continued without harm
Type of drug (notoriety)
High-risk drug according to previous case-control studies
Definite but lower-risk drug according to previous case-control studies
Several previous reports, ambiguous epidemiology results (drug "under surveillance")
All other drugs, including newly released ones
No evidence of association from previous epidemiological studies with a sufficient number of exposed controls
Other cause
Another drug with a probable or very probable score without this section
Please complete all sections.
Reference
B Sassolas, C Haddad, M Mockenhaupt et al. ALDEN, an algorithm for assessment of drug causality in Stevens-Johnson Syndrome and toxic epidermal necrolysis: comparison with case-control analysis. Clin Pharmacol Ther. 2010 Jul;88(1):60-8.
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