Objective: We aimed to evaluate the efficacy of and immunologic changes caused by subcutaneous immunotherapy (SCIT) in patients with allergy to cat and dog.
Methods: The study population comprised patients with rhinitis and/or asthma and allergy to cat or dog from a previous safety study. All patients had specific IgE to cat and/or dog. The SCIT maintenance dose was administered using an infusion pump over a single 4-hour session, followed by monthly administration over 6 months. Data were gathered on clinical outcomes, pulmonary function, FeNO, rhinitis and asthma symptoms, quality of life (QOL), and scores for the Asthma Control Test and symptom visual analog scale were recorded at baseline and then at 1, 3, and 6 months. Specific IgE and IgG antibody responses to cat and dog allergens were determined.
Results: The study population comprised 61 patients with a mean age of 35.6 (9.7) years, of whom 40 underwent SCIT for at allergy. A significant improvement was observed in rhinitis and asthma symptoms and in QOL, use of medication, visual analog scale score, and Asthma Control Test score at 1 month; these improvements persisted at month 6. The clinical improvement with cat extract was significantly more marked than with dog extract. Nearly half of the patients (49.09%) had an increase of >0.9 in the ESPRINT-15 QOL in allergic rhinitis questionnaire, and 58.18% had an increase of >0.5 in the Asthma Quality of Life Questionnaire score at month 6. Both differences represent the minimal clinical important difference. A significant increase was observed in specific IgG and IgE to different allergens at 3 and/or 6 months.
Conclusions: Ultrarush SCIT with cat and dog extracts has substantial clinical value for many patients.

Key words: Ultrarush subcutaneous immunotherapy, Cat, Dog, Allergy