ALLERGEN-SPECIFIC LOW-DOSE IMMUNOTHERAPY IN PERENNIAL ALLERGIC RHINITIS - A DOUBLE-BLIND PLACEBO-CONTROLLED CROSSOVER STUDY

In a double-blind placebo-controlled crossover study, 36 adults with p erennial allergic rhinitis were treated with daily subcutaneous inject ions of inhalant allergens, the doses of which had been predetermined by intradermal testing. The dose chosen for each allergen was the maxi mum intradermally tolerated dose (MITD) of that allergen, defined as 0 .05 ml of the strongest concentration in a 1:5 dilution series which d id not produce a positive wheal. Of the 27 who expressed a preference, 21 (78%) preferred the active preparation and six (22%) the placebo ( p = 0.006). Significant symptom relief was apparent on an analysis of total rhinitis symptom scores (p = 0.006), nasal blockage (p = 0.02), nasal discharge (p = 0.006), postnasal drip (9 = 0.02) and anosmia (p = 0.02). These results support the validity of allergen-specific low-d ose immunotherapy using the MITD.