Effect of prior medication on intradermal test response in patients with respiratory allergies

In a single-blind study of 23 patients with respiratory allergic disorders, we studied the effect of different antiallergic drugs on intradermal (ID) skin test response. After discontinuing the medication prescribed to patients, ID skin tests were done to determine the baseline values. The subjects were then randomly assigned different doses of different drugs orally, including theophylline (200 mg), salbutamol (4 mg), ephedrine (24 mg), and prednisolone (10 mg). Only epinephrine (1:1000) was injected subcutaneously (0.5 ml). ID skin tests were repeated 2 hours after the administration of the medicines that were taken orally. In the case of epinephrine, the tests were repeated 30 minutes after the injection. No significant differences could be observed in ID skin tests before and after the medication, irrespective of the test allergens.