Background Adverse drug reactions on skin affect approximately 2% of patients. Skin and drug challenge tests were performed in the dermatology department to assess these reactions and pharmacy-compounded drugs were tested through patches, pricks and intradermal (IDR) tests.

Purpose To assess the incidence of positive allergic reactions in tested patients and to define the culprit drugs and their potential allergic role in these reactions.

Materials and Methods The study was conducted between 2007 and 2010 on patients from our hospital. We collected information on the characteristics of the adverse drug reaction on skin, the drugs tested, the tests performed and their results.

Results In the period studied, 220 patients referred by other practitioners (from the hospital or from ambulatory practitioners) for serious cutaneous reactions were tested and 3225 preparations were performed by the pharmacy. 92 patients had an immediate reaction to the drug and 128 had a non-immediate reaction. 64 (29%) patients developed a positive response: 48 (75%) through skin tests (patch, prick and IDR) and 16 (25%) through a Drug Challenge Test (DCT). The drugs most often involved in the positive tests were anti-infectious drugs (46%), paracetamol (16%) and iodinated contrast media (10%).

Conclusions The percentage of positive tests in this cohort agrees with the data found in the literature (3–76%). The large difference is due to the variability in patient recruitment.

However, it is difficult to compare these data because the preparation and interpretation of the tests are not standardised.

Allergology tests still improve the care of patients as with negative skin tests and DPTs many patients were able to continue with their treatment.

Manufacturing tests by the pharmacy standardise preparation conditions within the hospital and reduce cross contamination and microbial contamination.

No conflict of interest.