Allergy diagnostic testing in clindamycin-induced skin reactions

In clinical practice, clindamycin is increasingly used because of its good tolerability and high efficacy with excellent tissue penetration. However, with increased application of clindamycin, the frequency of side effects such as skin eruptions rises and the need for diagnostic testing to identify clindamycin allergy increases. The aim of this retrospective analysis was to demonstrate the results of skin and challenge tests in cases of clinically suspected clindamycin allergy.

We evaluated 33 patients with a history of a skin reaction in temporal relation to treatment with clindamycin using standardized patch and prick skin testing. In the case of negative skin tests, oral challenges were performed.

Clindamycin hypersensitivity was excluded in 20 patients by negative skin tests and subsequently tolerated oral challenge tests. In 5 patients, positive skin tests strongly suggested delayed-type non-IgE-mediated allergic clindamycin hypersensitivity. In 6 skin test-negative patients (2 patients refused challenge tests), a rash was provoked by controlled challenge tests.

The evaluation of patients with clindamycin-associated skin reactions should include appropriate allergologic tests establishing or excluding the diagnosis of clindamycin hypersensitivity. Combined testing, i.e. skin tests and subsequent challenge tests, appears to be necessary to definitely confirm or rule out the presence of allergic clindamycin hypersensitivity.