Background: Subcutaneous allergen-specific immunotherapy (IT) is a proved, highly effective treatment for respiratory IgE-mediated diseases. However, few studies have explored the immunological mechanisms of IT in patients with atopic dermatitis. Objective: To explore the immune response of atopic dermatitis patients receiving house dust mite (HDM) immunotherapy, according to humoral response and basophil activation. Material and method: An open label study was done which assessed the severity of atopic dermatitis with SCORAD in 20 patients (10 with immunotherapy and 10 without it) every three months during two years. Serum samples were taken before the follow up, and at the rst and second year of study to analyze CD63 basophil expression, total IgE levels and speci c IgE and IgG4 to Der p and Der f. Ten patients with allergic rhinitis receiving IT and 5 non-allergic subjects were used as controls. Results: CD63 expression after basophil stimulation with Der p was higher in atopic dermatitis patients than in rhinitis and non-allergic subjects. After the rst and second year of treatment, CD63 expression was lower in atopic dermatitis active group than in the atopic dermatitis control group. We observed a correlation between SCORAD, IgG4 and CD63 expression. Conclusion: In patients with atopic dermatitis, basophil activation test could be a biomarker of clinical response and basophil modulation can result in a better clinical control.