Cutaneous adverse reactions to clindamycin: results of skin tests and oral exposure.

Background: Clindamycin is an antibiotic used in anaerobic and severe complicated infections. It is often selected for patients with a history of allergy to other antibiotics.

Objectives: To study the occurrence of clindamycin hypersensitivity and to determine whether skin tests are useful in cases of suspected clindamycin allergy.

Methods: Six patients with an exanthematous rash and a history strongly suggestive of clindamycin hypersensitivity were studied with skin tests and oral exposure. Cases of suspected adverse drug reactions to clindamycin reported to the National Register of Adverse Effects of Drugs (NRAED) in Finland during 1973-2000 were analysed.

Results: In the skin tests true-positive patch test reactions were seen in four of six patients, while 22 healthy control patients were negative. One false-positive and one false-negative patch test reaction were seen. During 1973-2000, 29 suspected cases of skin and/or mucosal membranes affected by clindamycin were reported to the NRAED.

Conclusions: Clindamycin hypersensitivity is not common. Delayed-type allergic reactions occur and patch tests are useful in those cases. Oral exposure is the method of choice if possible, as false-negative and false-positive reactions may occur.