Objective: This open clinical study was designed to investigate the occurrence of adverse reactions of specific immunotherapy (SIT) with horse dander and to recognize signs of efficacy regarding horse-induced cutaneous and respiratory symptoms.
Methods: Twenty-four patients attending our Outpatient Clinic in Huelva (Spain) with horse-induced allergy were selected for receiving a standardized extract of horse dander (Alutard SQ).
Results: Local and systemic reactions (five adverse reactions in four patients) were observed during the induction phase of treatment when administering the doses with the highest allergen concentration. Systemic side effects were mild, one immediate case consisting of wheezing and prompt response to treatment and one mild conjunctival hyperemia. Doses were reduced in all cases, and good tolerance to SIT was maintained. The sensitivity of patients to horse dander as assessed by deliberate natural exposure to horse decreased significantly when patients reached maintenance dose: Conjunctivitis symptoms were reduced in all patients, rhinitic symptoms in 93%, asthmatic symptoms in 90%, and cutaneous symptoms in 87% of the patients. Subjective assessment of a patient's allergic disease on a visual analog scale (VAS) showed an improvement. Ninety-five percent of the patients were highly satisfied with the treatment (efficacy, suitability, and troubles).
Conclusion: Specific immunotherapy with standardized horse-allergen extract is a safe treatment with the doses of allergen extract administered in the present study. In addition, it seems to have beneficial effects in patients with moderate-severe rhinoconjunctivitis and/or asthma.