Antihistamine medications must be stopped before skin prick testing and performing a food challenge. However antihistamines do not need to be stopped before blood testing. Short-acting antihistamines such as Piriton [Chlorpheniramine], Ucerax [Hydroxizine], Benadryl [Acrivastine] should be stopped 48 hours before skin testing.
Long-acting antihistamines such as Claritin [Loratadine], Neoclarytin [Desloratadine], Zirtek [Cetirizine], Xyzal [Levocetirizine], Telfast [Fexofenadine] need to be stopped 5 days before testing. Cough preparations for children frequently contain antihistamines and you should check for this and if they are present stop the cough preparation 48 hours before the visit.
Oral, nasal or inhaled steroid medications do not need to be stopped as they do not affect the test result. Anti-leukotrienes such as Singulair [Montelukast], Accolate [Zafirlukast] do not need to be stopped as they do not affect the test result. If in doubt, please contact the practice.