I am not sure if by normal you mean that spirometry/peak flow is the practice standard or that spirometry/peak flow is commonly performed with each allergy injection. It is not recommended that lung function testing be performed with each injection but many specialists perform peak flows in asthmatics who are receiving allergen immunotherapy. My approach is to establish a baseline peak flow in subjects with a history of severe asthma exacerbations or in patients who have less than normal lung function. If the peak flow is less than 15-20% of the target value, then the injection is not administered. The risk of severe anaphylaxis is greater with immunotherapy in asthmatics. Spirometry is more expensive and time consuming, and FEV1 correlates with peak flow. Thus, peak flow measurements can be used as a surrogate for FEV1.
I have provided a quote from the Allergen Immunotherapy Practice Parameter 2011.
“Summary Statement 32: An assessment of the patient’s current health status should be made before administration of the allergy immunotherapy injection to determine whether there were any health changes that might require modifying or withholding that patient’s immunotherapy treatment. Poorly controlled asthma has been identified as a risk factor for a severe immunotherapy-induced reaction. Before the administration of the allergy injection, the patient should be evaluated for the presence of asthma symptoms. One might also consider an objective measure of airway function (eg, peak flow) for the asthmatic patient before allergy injections. B
In the AAAAI’s survey of physician members on immunotherapy- and skin testing–induced fatal reactions and NFRs during the period of 1990-2001, 15 of the 17 fatalities occurred in patients with asthma, and in 9 patients not optimally controlled asthma was considered the susceptibility factor that contributed to the fatal outcome.143 The most severe NFR, respiratory failure, occurred exclusively in asthmatic patients, and 4 (57%) of 7 asthmatic patients had a baseline FEV1 of less than 70% of predicted value.185 In the most comprehensive evaluation of fatalities associated with allergen immunotherapy (1945-1987), there were 40 fatalities during allergen immunotherapy and 6 fatalities during skin testing.184 Sufficient information for complete analysis was provided for 30 patients. Ten fatalities occurred during seasonal exacerbation of the patient’s disease, 4 in patients who had been symptomatic at the time of the injection, 2 of whom had been receiving b-adrenergic blockers. Of the 24 fatalities associated with immunotherapy, 4 had experienced previous reactions, 11 manifested a high degree of sensitivity, and 4 had been injected with newly prepared extracts. In a prospective study of 125 asthmatic patients with mite allergy that used a 3-day rush immunotherapy protocol, FEV1 was identified as a predictor for systemic reactions.182 In this study 73.3% of the patients with an FEV1 of less than 80% of predicted value experienced an asthma reaction during rush immunotherapy, whereas only 12.6% of patients with an FEV1 of greater than 80% of predicted value had asthmatic reactions (P < .0001).The authors noted that if the patients with an FEV1 of less than 80% of predicted value had been excluded from the study, the systemic reaction rate would have been 19.7% instead of 36%. These studies suggest that labile asthma, severe asthma, or both is a risk factor for immunotherapy. In addition to symptomatic asthma and injections administered during periods of exacerbation of symptoms, other risk factors for immunotherapy that have been identified include the presence of a high degree of hypersensitivity, use of b-blockers, injections from new vials, and dosing errors.31 With the exception of dosing errors and a high degree of hypersensitivity, these risk factors can be minimized by performing a preinjection health screen before the administration of the allergy immunotherapy injection. This preinjection evaluation might include a health inquiry administered verbally or as a written questionnaire directed to determine whether there were any health changes that might require modifying or withholding that patient’s immunotherapy treatment. The preinjection health inquiry might include questions regarding the presence of asthma symptom exacerbation, b-blocker use, change in health status (including pregnancy), or an adverse reaction to the previous allergen immunotherapy injection.
The preinjection evaluation might also include a peak flow measurement to assess the airway function of asthmatic patients (an example of a written preinjection questionnaire can be found in the members section of www.aaaai. org). A patient’s asthma must be stable before the allergen immunotherapy injection is administered, and patients with significant systemic illness generally should not receive an allergy immunotherapy injection.”
In summary, it is not routine for all patients receiving immunotherapy to have an objective measurement of airflow with each injection. However, it is appropriate to measure a peak flow in subjects with asthma. I do not think it is necessary to perform spirometry with each visit for allergen immunotherapy.
I hope this information is of help to you.
All my best.
Dennis K. Ledford, MD, FAAAAI