Sensitivity to fungal allergens is a risk factor for life-threatening asthma

BACKGROUND: Previous studies have suggested that sensitivity to Alternaria and Cladosporium may be risk factors for life-threatening asthma. We have investigated this by studying the relationship between skin tests for fungal spores and admission to an intensive care unit (ICU) for asthma. METHODS: Skin prick tests for fungal spores (Alternaria tenuis, Cladosporium cladosporoides, Helminthosporium maydis, and Epicoccum nigrum), cat dander, house-dust mite (Dermatophagoides pteronyssinus), and a seven-grass mix were performed in three groups of patients: patients admitted to an ICU with an attack of asthma; those who had received emergency treatment for asthma but had not been admitted to an ICU, and those who had never required emergency treatment for their asthma. RESULTS: Twenty of 37 patients (54%) admitted to the ICU had a positive skin test for one or more fungal allergens compared with 15/50 patients (30%) in each of the other groups (P=0.005). The ICU patients were no more likely to have positive skin tests for the grass mix, cat dander, or house-dust mite than the other patients. CONCLUSIONS: A positive skin test for fungal allergens is a risk factor for admission to an ICU with an acute attack of asthma.     

Anti-acid medication as a risk factor for food allergy

An important feature for oral allergens is their digestion-resistance during gastrointestinal transit. For some oral allergens, digestion stability is an innate feature, whereas digestion-labile antigens may only persist in times of impairment of the digestive system. In this review, we collect evidence from mouse and human studies that besides the inherent molecular characteristics of a food protein, the stomach function is decisive for the allergenic potential. Gastric acid levels determine the activation of gastric pepsin and also the release of pancreatic enzymes. When anti-ulcer drugs inhibit or neutralize gastric acid, they allow persistence of intact food allergens and protein-bound oral drugs with enhanced capacity to sensitize and elicit allergic reactions via the oral route. Mouse studies further suggest that maternal food allergy arising from co-application of a food protein with anti-acid drugs results in a Th2-biased immune response in the offspring. Especially, anti-ulcer drugs containing aluminum compounds act as Th2 adjuvants. Proton pump inhibitors act on proton secretion but also on expression of the morphogen Sonic hedgehog, which has been related to the development of atrophic gastritis. On the other hand, atrophic gastritis and resulting hypoacidity have previously been correlated with enhanced sensitization risk to food allergens in elderly patients. In summary, impairment of gastric function is a documented risk factor for sensitization against oral proteins and drugs.     

Female sex as a risk factor for penicillin allergy.

BACKGROUND: Identification of risk factors is an integral part of a physician's evaluation of a patient. OBJECTIVE: To determine whether female sex is an independent risk factor for penicillin allergy. METHODS: Rates of positive penicillin skin test (PST) results, according to sex, were determined in patients with a history of penicillin allergy undergoing penicillin allergy evaluation with major and minor determinants of penicillin between June 1, 2002, and June 30, 2004. Univariate and multivariate logistic regression analyses were used to calculate unadjusted and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for sex differences in the rates of positive PST results. RESULTS: Of the 1,921 patients, 1,759 underwent PST and 157 did not; 5 medical records were not available for review. The mean patient age was 60 years. Sixty-four patients (4%) had a positive PST reaction; of these, 53 (83%) were females and 11 (17%) were males (OR, 3.6; 95% CI, 1.9-7.2; P < .001). In a multivariate logistic regression analysis adjusted for age, history of multiple drug allergies, and elapsed time from the initial penicillin adverse drug reaction to PST, female sex again had a significant risk of a positive PST reaction (OR, 3.2; 95% CI, 1.6-6.7; P = .001). CONCLUSION: A greater risk of penicillin allergy exists in association with female sex in patients with a history of penicillin allergy.     

Diet as a risk factor for atopy and asthma

It has been hypothesized that decreasing antioxidant (fruit and vegetables), increased n-6 polyunsaturated fatty acid (PUFA; (margarine, vegetable oil), and decreased n-3 PUFA (oily fish) intakes have contributed to the recent increases in asthma and atopic disease. Epidemiologic studies in adults and children have reported beneficial associations between dietary antioxidants and lipids and parameters of asthma and atopic disease. The associations with n-6 and n-3 PUFA appear to be very complex and might differ between asthma and atopic dermatitis. Dietary antioxidants are probably exerting antioxidant and nonantioxidant immunomodulatory effects. Dietary lipids exert numerous complex effects on proinflammatory and immunologic pathways. It has also been suggested that atopic dermatitis is associated with an enzyme defect in lipid metabolism. In spite of this, the results of interventional supplementation studies in established disease have been disappointing, and there is now increasing interest in the possibility that dietary antioxidant and lipid intakes might be important in determining expression of disease during pregnancy and early childhood and that dietary interventions should be targeted at these groups. It also seems likely that there is individual variation in the responses of individuals to lipid, and probably antioxidant, supplementation. Further research to determine whether dietary intervention can reduce the risk of asthma and atopic disease is justified.     

Food allergy is associated with an increased risk of asthma

Background The atopic march is well documented, but the interrelationship of food allergy (FA) and asthma is not well understood.
Objective The aim of this study was to examine the strength of the association and temporal relationships between FA and asthma.
Methods This analysis included 271 children 6 years (older group) and 296 children <6 years (younger group) from a family-based FA cohort in Chicago, IL. Asthma was determined by parental report of physician diagnosis. FA status was determined based on the type and timing of clinical symptoms after ingestion of a specific food, and results of prick skin test (Multi-Test II) and allergen-specific IgE (Phadia ImmunoCAP). Analyses were carried out using logistic regression accounting for important covariates and auto-correlations among siblings. Kaplan–Meier curves were used to compare the time to onset of asthma with the FA status.
Results Symptomatic FA was associated with asthma in both older [odds ratio (OR)=4.9, 95% confidence interval (CI): 2.5–9.5] and younger children (OR=5.3, 95% CI: 1.7–16.2). The association was stronger among children with multiple or severe food allergies, especially in older children. Children with FA developed asthma earlier and at higher prevalence than children without FA (Cox proportional hazard ratio=3.7, 95% CI: 2.2–6.3 for children 6 years, and hazard ratio=3.3, 95% CI: 1.1–10 for children <6 years of age). No associations were seen between asymptomatic food sensitization and asthma.
Conclusions Independent of markers of atopy such as aeroallergen sensitization and family history of asthma, there was a significant association between FA and asthma. This association was even stronger in subjects with multiple food allergies or severe FA.     

Food allergy and additives: triggers in asthma

Exposure to food allergens can cause a varied pattern of respiratory symptoms, with allergic responses ranging from asthma symptoms to occupational asthma. Food allergy in a patient presenting as asthma tends to indicate a more severe disease constellation. Patients with underlying asthma experience more severe and life-threatening allergic food reactions. When a food reaction involves respiratory symptoms, it is almost always a more severe reaction compared with reactions that do not involve the respiratory tract. Susceptible patients may even react to a causative food on inhalation without ingestion. However, isolated asthma or rhinitis symptoms without concomitant cutaneous or gastrointestinal symptoms are rare events.     

Maternal diet during pregnancy: an emerging risk factor for childhood asthma

Evaluation of: Willers SM, Wijga AH, Brunekreef B et al. Maternal food consumption during pregnancy and the longitudinal development of childhood asthma. Am. J. Respir. Crit. Care Med. 178, 124–131 (2008).

It has been hypothesized that the recent marked increase in the prevalence of asthma may, in part, be a consequence of changing diet. There is increasing interest in the possibility that childhood asthma may be influenced by maternal diet during pregnancy and an increasing number of studies have highlighted associations between childhood asthma and maternal intake of certain foods (e.g., fish, fruits and vegetables) and nutrients (e.g., vitamin E, vitamin D, zinc and polyunsaturated fatty acids) during pregnancy. Maternal diet during pregnancy has the potential to influence fetal immune and airway development during a critical period of life with long-term irreversible consequences, such as childhood asthma. Further research, particularly intervention studies, needs to be carried out to establish whether dietary intervention during pregnancy can be used as a healthy, low-cost, public-health measure to reduce the prevalence of childhood asthma.     

Role of food allergy in asthma in childhood

Atopy is the major predisposing factor for asthma identified up to now, and allergen exposure, particularly indoor allergens, is considered as a causal factor for asthma. Food allergy is frequently underestimated in association with asthma, however food allergy has been shown to trigger or exacerbate broncho-obstruction in 2 to 8.5% of children with asthma. There is also evidence that double-blind placebo-controlled oral challenge is able to increase unspecific bronchial hyperresponsiveness. Sensitization to food can occur early in life involving T cell response, mainly of the Th2 phenotype, but also IgE-mediated hypersensitivity. Moreover, it has been shown that sensitization to food allergens early in life is a risk factor for sensitization to inhalent allergens and respiratory symptoms later on. Epidemiological studies suggest that changes in the dietary composition, such as trans-fatty acids, could be involved in the increase of asthma prevalence. The introduction of formula during the first trimester of life increases the risk of having asthma. The diagnosis of food allergy associated with asthma is not easy, nevertheless is important for allergists, pulmonologists and paediatricians to consider food allergy in children with respiratory symptoms, especially when asthma symptoms start early in life and when they are associated with other manifestations of food allergy. Children sensitized to cow's milk proteins and also having atopic eczema are at higher risk for asthma. Since avoidance of the offending food is the first step in the management of children with asthma associated with food allergy, a careful identification should be done in order to avoid unnecessary elimination of foods.     

Living in towers as risk factor of pollen allergy

BACKGROUND: The effects of fluctuations in pollen counts have important implications for health services. Little research on the clinical implications of the vertical distribution of pollen in allergy symptoms has been carried out. METHODS: We have investigated the allergic symptoms of a population of 17 171 patients coming from our health area (Valladolid, Spain) and living in the city and villages. We compared the prevalence of sensitization to different pollens: Graminae, trees and shrub in relation with the floor of the building where they were living. RESULTS: Relative risk of pollen sensitization (confidence index, CI 95%) was higher in patients who were living at high floors than in those patients who were living in lower floors or at street level, independently of rural or urban conditions The chi-square showed a lineal trend in this relationship in the case of sensitization to grass pollen: chi(2): 1794, P > 0.00001 CONCLUSIONS: On the basis of our local investigations, natural pollen sensitization appears to increase with height where the patient lives. This paper reports clinical results on the influence of vertical pollen distribution in pollen allergy.