Sensitisation to airborne moulds and severity of asthma: cross sectional study from European Community respiratory health survey

Abstract

Objective To assess whether the severity of asthma is associated with sensitisation to airborne moulds rather than to other seasonal or perennial allergens. Design Multicentre epidemiological survey in 30 centres. Setting European Community respiratory health survey. Participants 1132 adults aged 20-44 years with current asthma and with skin prick test results. Main outcome measure Severity of asthma according to score based on forced expiratory volume in one second, number of asthma attacks, hospital admissions for breathing problems, and use of corticosteroids in past 12 months. Results The frequency of sensitisation to moulds (Alternaria alternata or Cladosporium herbarum, or both) increased significantly with increasing asthma severity (odds ratio 2.34 (95% confidence interval 1.56 to 3.52) for either for severe v mild asthma). This association existed in all of the study areas (gathered into regions), although there were differences in the frequency of sensitisation. There was no association between asthma severity and sensitisation to pollens or cats. Sensitisation to Dermatophagoides pteronyssinus was also positively associated with severity. In multivariable logistic regressions including sensitisation to moulds, pollens, D pteronyssinus, and cats simultaneously, the odds ratios for sensitisation to moulds were 1.48 (0.97 to 2.26) for moderate v mild asthma and 2.16 (1.37 to 3.35) for severe v mild asthma (P < 0.001 for trend). Conclusions Sensitisation to moulds is a powerful risk factor for severe asthma in adults. This should be taken into account in primary prevention, management, and patients' education.

Sensitization to Common Allergens in Adults with Asthma

“…6 At the Portland, OR, site in the European Community respiratory health survey (ECRHS) studies, 74% of the 39 participants with asthma were sensitized to at least one of 9 common allergens, the most frequent sensitizations being to timothy grass, D. pteronyssinus, birch, A. alternata, and cat. 5 Thus, studies in the United States have consistently observed a high prevalence of atopy among adult asthmatics, with the distribution of specific allergen sensitivities varying between sites. The same observations were reported in the ECRHS studies conducted at 30 sites, mostly in Europe.…”

“…The investigations that have been reported were at single sites and tended to have small sample sizes. 5,6,9 In a study of patients being evaluated by radioallergosorbent testing in New York City, asthmatics were more likely than non-asthmatics to be hypersensitized to cat dander or dust mites (D. farinae) and to Deuteromycetes molds (Alternaria tenuis, Aspergillus fumigatus, and Cladosporium herbarum), whereas pollen (tree, grass, ragweed) hypersensitivity was not independently associated with asthma. 9 Although cat dander was excluded from another New York City study of allergic sensitization, 6 most (83%) of the 29 adults with asthma had a positive skin prick test to at least one of 7 common allergens or allergen mixtures: ragweed, grasses, dust mite (Dermatophagoides pteronyssinus and D. farinae), and trees.…”

“…The same observations were reported in the ECRHS studies conducted at 30 sites, mostly in Europe. 5,[13][14][15][16] Many studies have also explored the utility of total serum IgE as a marker of atopy and found some level of discordance with allergen-specific tests. 3,17 In this study, 21% of patients had a positive allergen-specific test while exhibiting normal total IgE.…”

“…Updated National Asthma Education and Prevention Program (NAEPP) guidelines recommend allergy testing for persons with persistent asthma and, after sensitivity is determined, avoidance of the trigger and allergen abatement. 8 Few studies done in the United States, however, have provided information about atopy and adult asthma 5,6,9 or investigated the extent to which measurement of atopy might influence medical decisions. Because more than 4 million visits per year by asthma patients are to family practitioners and other generalists, 10 awareness of the prevalence of atopy among asthma patients may help to improve asthma patient management by these physicians.…”

“…3,4 Evidence suggests that sensitization to common allergens, including molds and dust mites, correlates with greater asthma severity. [5][6][7] Knowledge of sensitivity to specific allergens is an important guide to asthma management, through allergen avoidance, immunotherapy, and pharmacological treatment of allergies. Updated National Asthma Education and Prevention Program (NAEPP) guidelines recommend allergy testing for persons with persistent asthma and, after sensitivity is determined, avoidance of the trigger and allergen abatement.…”