Allergy to oak pollen in North America

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 ∼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.

Birch-naive, oak-allergic subjects' response to birch pollen in an environmental chamber

Background: Oak and birch pollens are strongly cross-reactive. It is unknown how robust this cross-reactivity is in patients without natural exposure to pollen of both trees. We assessed the symptom response to birch pollen in subjects with skin-prick test (SPT) results positive to oak and birch but only naturally exposed to oak by using an allergen challenge chamber. Methods: The subjects with SPT results positive to oak and birch had their serum-specific immunoglobulin E (ssIgE) to oak and birch antigens measured. Residential historical data were obtained. The subjects were exposed to birch pollen (3500 ± 700 grains/m³) in two consecutive 3-hour challenges. Symptoms were recorded at baseline and 30-minute intervals. Results: Twenty-four subjects, 12 men; ages 20-58 years, completed the study. Sixteen subjects (66.7%) responded with high Total Symptom Scores (TSS) ≥10 of a maximum 21. Twelve subjects (50%) had ssIgE values ≥0.70 kU/L to oak, 10 of whom had ssIgE values ≥0.70 kU/L to birch. These 10 subjects had a significantly higher maximum TSS than the rest. Also, 15 subjects without a previous natural exposure to birch pollen responded with TSS equivalent to the 9 subjects with previous exposure. Conclusion: Virginia live oak ssIgE levels of patients allergic to oak and birch correlated with the symptom response to birch pollen exposure, even without previous natural exposure to birch. The subjects naive to birch pollen responded to birch pollen exposure with symptoms comparable with both those with previous sustained exposure and also those who resided in endemic areas, as reported by other researchers.