Inhalation Challenge With Bovine Dander Allergens
November 10th, 2014 by admin | Posted in Allergy
Conclusion: Only the SPT with bovine allergens and bovine-specific serum IgE measurements were useful in selecting patients for the bSIC. This challenge should not be performed in SPT-negative subjects. A diagnosis of occupational asthma due to bovine dander allergens could be made without an inhalation challenge test in asthmatic patients with high bovine-specific serum IgE levels. This practice would eliminate the need for the majority of bSICs. 
Abbreviations: CI = confidence interval; bIgE = bovine-specific IgE; bSIC = specific inhalation challenge with bovine dander allergens; NO = nitric oxide; NPV = negative predictive value; PC = provocative concentration; PC20 = provocative concentration of a substance causing a 20% fall in FEV1; PD = provocative dose; PEF = peak expiratory flow; PPV = positive predictive value; RDR = response/dose ratio; SIC = specific inhalation challenge; SPT = skin-prick test
Darming increases the risk of asthma more than any other occupation in Finland, and the incidence rate of occupational asthma is high among farmers. Bovine dander allergens are responsible for most cases of occupational asthma among Finnish farmers, with 60 to 110 new cases being recorded annually. Specific inhalation challenge (SIC) with an occupational agent is thought to be the most
However, SIC is a time-consuming and expensive method that is often carried out on an inpatient basis. Although it is usually well-tolerated, one has to bear in mind that SIC can provoke severe acute reactions, as well as a late reaction. In addition, it can induce an exacerbation of asthma, with recurrent nocturnal symptoms lasting for several days. Due to these economic and ethical reasons, the selection of patients to undergo SICs should be done with Health Care Canadian pharmacy.
Occupational asthma can be caused by low-molecular-weight agents or high-molecular-weight agents, and the bovine dander allergens belong to the latter group. In the case of high-molecular-weight allergens, the early response to SIC may be predicted with a knowledge of bronchial responsiveness to either histamine or methacholine, and of the level of allergen sensitization either by skin test or by measuring the serum level of specific IgE. Therefore, the performance of an SIC to a high-molecular-weight allergen may not be mandatory in all cases of occupational asthma, and the main diagnostic indication of SIC may be its use in asthmatic subjects with a low-degree allergy. The problem is how to identify those patients who would benefit most from an SIC.