A 1-day imported fire ant rush immunotherapy schedule with and without premedication.

BACKGROUND: Rush immunotherapy (RIT) schedules can expedite protection in individuals sensitive to imported fire ant (IFA) stings. OBJECTIVE: To evaluate the safety and efficacy of 1-day RIT with IFA whole body extract (WBE) and determine the benefit of premedication with antihistamines and prednisone. METHODS: Patients with systemic reactions to IFAs and evidence of specific IgE by skin test or serologic test started a 1-day RIT protocol without premedication. The 1-day RIT protocol consisted of a total of 10 injections every 30 to 60 minutes to achieve a 0.3-mL 1:100 (wt/vol) dose. A higher systemic reaction rate (SRR) prompted protocol revision to include a 3-day course of oral 20 mg of prednisone twice daily, 150 mg of ranitidine, and 10 mg of loratadine started 2 days before the 1-day RIT. Patients returned on days 8 and 15 to receive a 0.5 mL 1:100 (wt/vol) maintenance injection. The effectiveness of the RIT was evaluated with a sting challenge on approximately day 22. RESULTS: Eighty of the 96 patients enrolled initiated the 1-day RIT. The first nonpremedicated group exhibited a SRR of 24.3% (9 of 37 patients), whereas the revised premedicated group had a SRR of 9.5% (4 of 42 patients; P = .07). The most severe reaction during RIT included dizziness, angioedema, and urticaria. Sting challenges on 53 patients resulted in 1 mild rhinitis reaction (efficacy, 98.1%). CONCLUSION: One-day RIT with IFA WBE for IFA hypersensitivity is efficacious. Although there was a trend with premedications to reduce SRRs during the RIT, safety data with premedication require confirmation in a larger trial.

Inhalant horse allergens and allergies: a review of the literature.

A wealth of literature exists regarding common allergies to household pets such as cat or dog. Allergy to horse, however, is infrequently discussed in the medical literature despite significant sensitization rates among urban-dwelling subjects without direct exposure to horses. A literature search was conducted in PubMed and additional references were collected from surveying the references of the pulled articles. This review summarizes aspects of IgE-mediated horse allergy including the prevalence and mechanisms for sensitization, clinical presentation, molecular characterization of the major and minor horse allergens, and the role of allergen immunotherapy. There is currently only one horse immunotherapy study showing significant improvement in clinically sensitive patients. The 1997 World Health Organization Position Paper on Immunotherapy lists horse immunotherapy among the areas needing further clinical research. Inclusion of horse into the standard allergen panel for children and adults has been supported by several authors, although further identification and characterization of horse antigens is needed to provide the most efficacious extract. As clinicians, we need to be aware of the potential cross-reactivity among the common mammalian allergens and consider the possibility of known or occult exposure to horse as a possible source of symptom exacerbation in susceptible individuals.