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FS09.5
Patch testing with allopurinol and oxypurinol in drug eruptions
Author(s) -
Vieira Ricardo,
Gonçalo M,
Figueiredo A
Publication year - 2004
Publication title -
contact dermatitis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.524
H-Index - 96
eISSN - 1600-0536
pISSN - 0105-1873
DOI - 10.1111/j.0105-1873.2004.0309ch.x
Subject(s) - allopurinol , medicine , toxic epidermal necrolysis , erythroderma , exfoliative dermatitis , dermatology , pharmacology , carbamazepine , psychiatry , epilepsy
Background: Drug eruptions as maculopapular rash, hypersensitivity syndrome, Stevens‐Johnson syndrome or toxic epidermal necrolysis occur in about 2% of patients taking allopurinol. The allopurinol oxidation product – oxypurinol – seems to be responsible for these hypersensitivity reactions. Opposing what occurs during the study of drug eruptions induced by other drugs as carbamazepine or amoxiciline, patch testing with allopurinol is usually negative. Objective: To evaluate skin reactivity to allopurinol and oxypurinol by patch testing in patients with a previous history of drug eruption related with allopurinol. Methods: 10 patients (6 females and 4 males) with drug eruptions induced by allopurinol with a high imputability index (6 hypersensitivity syndromes, 2 Stevens‐Johnson syndromes, 1 erythroderma and 1 toxic epidermal necrolysis) were patch tested with allopurinol in vaseline (10 and 20%) and with oxypurinol in vaseline (10 and 20%), acetone (10 and 20%) and alcohol (10 and 20%). Results: Patch tests with allopurinol and oxypurinol were invariably negative after 48 and 96 hours in all patients tested. Conclusion: Patch testing with oxypurinol as well as with allopurinol is usually negative and therefore is not helpful in the confirmation of these hypersensitivity reactions to allopurinol.