Patient’s compliance with allergen immunotherapy.

BACKGROUND: Allergen immunotherapy (IT) is an effective treatment of respiratory allergy, but requires strict rules of performance. This makes compliance particularly relevant, but thus far only a few studies have investigated this issue. METHODS: We reviewed all the available articles on compliance and adherence with IT in its different forms of administration, ie, subcutaneous (SCIT), sublingual (SLIT), and local nasal (LNIT). RESULTS: Early studies, when only SCIT was available, reported a low compliance, ranging from 45% to 60%, but the demanding schedules used, with very frequent injections, accounted for this outcome, as shown by patients' recognition of inconvenience as the major cause of noncompliance. The most recent studies reported a good compliance, estimated in 75% to 90%, to both SCIT and SLIT, inconvenience remaining the major cause of noncompliance, followed by cost of the treatment. The only study addressing LNIT found a very poor compliance (27%), the major cause being the side effects, with repeated nasal reactions to the allergen extract. CONCLUSIONS: Adequate education of patients and optimization of administration schedules, with fine balancing between dose effectiveness and cost, are the factors most likely to achieve further improvement of compliance with IT.