Effect of theophylline and terbutaline on immediate skin tests.

A questionnaire survey of board-certified allergists revealed that conflicting ideas exist as to the effect that drugs such as theophylline and beta 2 agonists have an immediate skin tests. Approximately half of the respondents felt these drugs would obscure a skin response; the remainder would not withdraw the drugs prior to testing. As a result of this difference in opinion, we studied the effects of these drugs on skin tests in seven subjects taking terbutaline (5 mg three times daily) and 13 subjects taking theophylline (3 to 5 mg/kg every 6 hr). Neither an acute loading dose nor chronic administration of either drug singly produced significant changes in wheal size in response to histamine, ragweed, or grass allergens. We conclude that theophylline and terbutaline administered singly at these doses have no effect on immediate skin tests.