Long-term adherence strategies for allergen immunotherapy

Adherence is crucial for allergen immunotherapy (AIT) efficacy, and a long-term 3-year adherence is indispensable for the long-term benefits beyond AIT administration. Nonadherence causes should be analyzed not only at the patient level but from a broader perspective, including socioeconomic factors, health-care system factors, and disorder- and therapy-related factors. Subcutaneous immunotherapy (SCIT) adherence is similar to 50% at best and, for sublingual immunotherapy, the numbers are even much worse in some regions. In this review, causes for AIT loss of adherence and strategies, published and from personal experience, to reduce nonadherence are presented. Although the broader picture of causes of nonadherence has to be taken into account, in all this, the patient-physician and patient-health care professional (AIT nurse, assistant) are still in the center, and, in SCIT, each clinic visit for a shot is an opportunity to exploit this interaction in a positive way and stimulate adherence. Patient factors of nonadherence are not so much forgetfulness but more perception of ineffectiveness and adverse effects. An explanation of what can be expected before starting AIT is crucial because most of those who drop out are seen during the first year. Adherence is especially under risk when administration is temporarily interrupted (lockdown, illness, disease flare, vacation, preseasonal AIT administration schedules). The pandemic has caused higher rates of nonadherence specifically due to a fear of getting infected with severe acute respiratory syndrome coronavirus 2, which can be mitigated with good hygiene techniques and strict sanitization protocols, which ensure the patients. Also, patient mobile discussion networks related to AIT can help encourage adherence and reduce fear of infection, even in these difficult times.