TL;DR: A subject's environmental exposure to endotoxin may have a crucial role in the development of tolerance to ubiquitous allergens found in natural environments.
Abstract: Background In early life, the innate immune system can recognize both viable and nonviable parts of microorganisms. Immune activation may direct the immune response, thus conferring tolerance to allergens such as animal dander or tree and grass pollen. Methods Parents of children who were 6 to 13 years of age and were living in rural areas of Germany, Austria, or Switzerland where there were both farming and nonfarming households completed a standardized questionnaire on asthma and hay fever. Blood samples were obtained from the children and tested for atopic sensitization; peripheral-blood leukocytes were also harvested from the samples for testing. The levels of endotoxin in the bedding used by these children were examined in relation to clinical findings and to the cytokine-production profiles of peripheral-blood leukocytes that had been stimulated with lipopolysaccharide and staphylococcal enterotoxin B. Complete data were available for 812 children. Results Endotoxin levels in samples of dust from th...
TL;DR: Allergic rhinitis (AR) is a heterogeneous disorder that despite its high prevalence is often undiagnosed as mentioned in this paper, and it is characterized by one or more symptoms including sneezing, itching, nasal congestion, and rhinorrhea.
Abstract: Allergic rhinitis (AR) is a heterogeneous disorder that despite its high prevalence is often undiagnosed. It is characterized by one or more symptoms including sneezing, itching, nasal congestion, and rhinorrhea. Many causative agents have been linked to AR including pollens, molds, dust mites, and animal dander. Seasonal allergic rhinitis (SAR) is fairly easy to identify because of the rapid and reproducible onset and offset of symptoms in association with pollen exposure. Perennial AR is often more difficult to detect than SAR because of the overlap with sinusitis, respiratory infections, and vasomotor rhinitis. SAR can result in hyperresponsiveness to allergens such as cigarette smoke, once pollen season is over. Perennial AR is defined as occurring during approximately 9 months of the year. AR affects an estimated 20 to 40 million people in the United States alone, and the incidence is increasing; an estimated 20% of cases are SAR; 40% of cases are perennial rhinitis; and 40% of cases are mixed. The pathophysiology of SAR is complex. There is a strong genetic component to the allergic response, which is driven through mucosal infiltration and action on plasma cells, mast cells, and eosinophils. The allergic response occurs in two phases, which are considered the “early” and “late” phase responses. Early phase response occurs within minutes of exposure to the allergen and tends to produce sneezing, itching, and clear rhinorrhea; late phase response occurs 4 to 8 hours after allergen exposure and is characterized by congestion, fatigue, malaise, irritability, and possibly neurocognitive deficits. The key to diagnosis of AR is awareness of signs and symptoms. IgE antibody tests to detect specific allergens are the standard method used today; however, in addition, diagnosis must be confirmed with a positive history and demonstration that the symptoms are the result of IgE-mediated inflammation. (J Allergy Clin Immunol 2001;108:S2-8.)
TL;DR: Measured by bronchial challenge, the catAllergen-treated patients could tolerate 11 times more allergen at the end than at the start of the study, and they also demonstrated a tendency toward less pronounced symptoms after exposure to cat and dog allergens.
Abstract: Forty-one patients (21 adults and 20 children) with cat dander- or dog dander-induced asthma were selected for immunotherapy with standardized and partially purified cat- or dog-dander extracts by use of a double-blind protocol. Based on sex, age, clinical history, results of bronchial challenge, and crossed radioimmunoelectrophoresis studies, the patients were stratified in matched pairs, and the treatment alternatives were distributed randomly among the pairs. Twenty-two patients treated with allergen (15 with cat allergen and seven with dog allergen) and 17 patients receiving placebo therapy completed the first year of treatment. In the cat allergentreated group, the bronchial sensitivity toward cat and histamine decreased ( p p
TL;DR: Evidence has accumulated that exposure to indoor allergen causes asthma and allergy, but this effect may depend on dose and type of aller Genetically susceptible children as well as the underlying genetic susceptibility of the child.
Abstract: Common indoor allergens include house dust mite, cockroach, animal dander, and certain molds. In genetically susceptible children, exposure to these indoor allergens during the critical postnatal period may lead to sensitization in early childhood. Consistent evidence indicates that children sensitized to common indoor allergens are at several-fold higher risk of asthma and allergy. Due to conflicting evidence from prospective studies, some doubt remains regarding a direct and dose-response relationship between exposure and development of asthma. However, in recent years, evidence has accumulated that exposure to indoor allergen causes asthma and allergy, but this effect may depend on dose and type of allergen as well as the underlying genetic susceptibility of the child.
TL;DR: A novel form of anaphylaxis and urticaria that occurs 3 to 6 hours after eating mammalian meat is not uncommon among children in this area and should certainly be considered for children living in the area where the Lone Star tick is common.
Abstract: BACKGROUND AND OBJECTIVE: Despite a thorough history and comprehensive testing, many children who present with recurrent symptoms consistent with allergic reactions elude diagnosis. Recent research has identified a novel cause for “idiopathic” allergic reactions; immunoglobulin E (IgE) antibody specific for the carbohydrate galactose-α-1,3-galactose (α-Gal) has been associated with delayed urticaria and anaphylaxis that occurs 3 to 6 hours after eating beef, pork, or lamb. We sought to determine whether IgE antibody to α-Gal was present in sera of pediatric patients who reported idiopathic anaphylaxis or urticaria. METHODS: Patients aged 4 to 17 were enrolled in an institutional review board–approved protocol at the University of Virginia and private practice allergy offices in Lynchburg, VA. Sera was obtained and analyzed by ImmunoCAP for total IgE and specific IgE to α-Gal, beef, pork, cat epithelium and dander, Fel d 1, dog dander, and milk. RESULTS: Forty-five pediatric patients were identified who had both clinical histories supporting delayed anaphylaxis or urticaria to mammalian meat and IgE antibody specific for α-Gal. In addition, most of these cases had a history of tick bites within the past year, which itched and persisted. CONCLUSIONS: A novel form of anaphylaxis and urticaria that occurs 3 to 6 hours after eating mammalian meat is not uncommon among children in our area. Identification of these cases may not be straightforward and diagnosis is best confirmed by specific testing, which should certainly be considered for children living in the area where the Lone Star tick is common.