Skin Prick Test Reactivity Research Articles

Sensitization to airborne allergens among adults and its impact on allergic symptoms: a population survey in northern Vietnam

BackgroundThe knowledge about allergic sensitization and its relationship with clinical symptoms and diseases among adults in South-East Asia is poor. The aim of this study was to investigate the prevalence and pattern of allergic sensitization and the association with asthma and allergic rhinitis in adults in urban and rural Vietnam.MethodsAmong 5,782 responders to a questionnaire survey in northern Vietnam, a random sample was invited to a clinical follow-up and 684 (46%) participated. The methods included a structured interview using a modified GA2LEN study questionnaire on symptoms and possible determinants for diseases. Skin prick test (SPT) with ten common airborne indoor and outdoor allergens, lung function test, and methacholine test was performed among subjects ≤60 years of age.ResultsIn total, one third of subjects had a positive SPT reaction to at least one allergen, 36.9% of men and 31.0% of women (n.s.). The most common sensitizer was the storage mite B. tropicalis (men 27.7%; women 18.7%) followed by house dust mite D. pteronyssinus (men 16.5%; women 10.6%), and D. farinae (men 15.3%; women 6.3%), and cockroach (men 16.5%; women 10.2%). Sensitization to all major allergens were significantly more common among men and among subjects ≤45 years compared with women and subjects >45 years, respectively. The prevalence of sensitization to animals, pollen and molds were low. The majority of cockroach-sensitized subjects were also sensitized to mites. Sensitization to any allergen and all major allergens were significantly associated with rhinitis, but not with asthma. However, bronchial hyper-reactivity was significantly associated with increasing number of positive SPTs (p = 0.047).ConclusionsAmong adults in northern Vietnam sensitization to mite and cockroach most common in both rural and urban areas. The dominant sensitizer was the storage mite B. tropicalis, which should be included in future studies and also in clinical practice, owing to its association with clinical symptoms. As in the Western world allergic sensitization was associated with rhinitis and bronchial hyper-reactivity. The lack of association with asthma in South-East Asia needs to be studied further.

Skin prick test and basophil reactivity to cetuximab in patients with IgE to alpha-gal and allergy to red meat

Severe hypersensitivity reactions to red meat with delay of several hours in patients with IgE to alpha-gal (galactose-alpha-1,3-galactose) have been reported. The diagnosis of meat allergy is difficult, because of the limited sensitivity of skin prick tests and specific IgE tests to meat extracts. These circumstances have been explained by the delayed expression of alpha-gal due to digestive processes. Because of the low sensitivity of skin prick tests to meat, we studied the possibility to perform skin prick tests with cetuximab, which carries the alpha-gal epitope. Skin prick and intradermal tests with cetuximab were clearly positive in 2 of 2 patients. As a further diagnostic step, we performed basophil activation tests with cetuximab. Skin prick tests and basophil activation test using cetuximab may be a more sensitive alternative in patients with an assumed allergy to meat.

Sensitization to Beer Ingredients in Chinese Individuals with Beer Allergy: A Clinical Study of 20 Cases

Background: Rare case reports of allergic reactions to beer have been published, but the nature of the eliciting substances in beer ingredients is often unknown. Objective: It was the aim of this study to identify sensitization patterns against various beer ingredients in Chinese individuals with beer allergy. Methods: Twenty-seven Chinese individuals with a clear-cut history of beer allergy were prescreened to answer a specific questionnaire related to the history and symptoms of beer allergy. Twenty individuals underwent allergy diagnostics with different food allergens and extracts of beer ingredients using the skin prick test (SPT) and the open oral provocation test (OPT) with beer. Results: Fifteen patients (75%) showed positive reactions to one or more beer ingredients. Of these, 9 individuals, reactive to sorghum and/or sorghum malt also showed positive reactions to other ingredients. Seventeen individuals showed variable symptoms after the OPT. Cutaneous erythema and urticaria were the most common symptoms and usually persisted for over 2 h. There were no significant differences in SPT reactivity to beer ingredients between male and female individuals. Single patients reacted to barley, hops or yeast. Conclusions: Sensitization to sorghum and/or sorghum malt was the most common finding in Chinese individuals with beer allergy.

Wheal and flare reactions in skin prick tests of patients treated with montelukast alone or in combination with antihistamines

Background Because antileukotrienes may inhibit inflammation, it is plausible that montelukast administered for a long time could suppress skin wheal and flare reaction, and thus, it should be discarded prior to the tests. This study assessed the effect of long-lasting treatment with montelukast alone or in combination with antihistamines on wheal and flare in skin pricks tests (SPT) in patients sensitized to perennial allergens.MethodsWe conducted a 32-week, double-blind, placebo-controlled, cross-over and randomized trial that implicated two arms: arm A, 20 patients received levocetirizine, montelukast with or without levocetirizine or placebo; arm B, 20 patients received desloratadine, montelukast with or without desloratadine or placebo. All treatment periods lasted 6 weeks and were separated by 2-week washouts. At baseline and on the last day of each treatment period, SPT were performed in all participants.ResultsBoth levocetirizine and desloratadine in monotherapy, or in combination with montelukast, were effective in reducing wheal and flare in SPT. Monotherapy with montelukast did not change the size of the wheal for either histamine or for house dust mites, in either arm of the study, but significantly reduced the size of flare for histamine in arm A. Addition of montelukast to antihistamine did not exceed efficacy of monotherapy with antihistamine in both arms of the study.ConclusionsSince the size of wheal determines the results of SPT, montelukast, even taken for a long time, does not have to be discarded prior to the tests.

Hygiene, atopy and wheeze–eczema–rhinitis symptoms in schoolchildren from urban and rural Ecuador

BackgroundRural residence is protective against atopy and wheeze–rhinitis–eczema symptoms in developed countries, an effect attributed to farming and poor hygiene exposures. There are few data from developing countries addressing this...

Relationship between skin prick and atopic patch test reactivity to aeroallergens and disease severity in children with atopic dermatitis

BackgroundThe immunological mechanism in aetiology of atopic dermatitis (AD) shows significant differences from other allergic diseases. Allergen inhalation exacerbates AD lesions and AD patients’ complaints decrease in house dust mite (HDM) low level environments, which reveals the importance of inhalant allergens. ObjectiveWe evaluated the skin prick test (SPT) and atopy patch test (APT) positivity rates with aeroallergens and studied the effect of test results, and aimed to determine the value of allergic test reactivity on the clinical characteristics of children with AD. MethodsForty-five children aged 2–15 years with AD were included to study between May 2006 and May 2007 in GATA Haydarpasa Teaching Hospital, Allergy Department. The reactivity to inhalant allergens using SPT and APT was evaluated. The severity of AD, which was assessed with SCORAD, was compared with aeroallergen hypersensitivity. ResultsThe highest positivity of APT was seen against HDM (48.9%). HDM SPT positivity and subjective symptoms score were statistically correlated (P<0.05). Patients with strong SPT positivity to HDM had a higher total SCORAD score (P<0.05). Although there was no statistical correlation between HDM APT and SCORAD parameters, APT positive patients had generally higher SCORAD parameters. The statistical significance was only shown between the extent of the disease and strong APT positive reactions to Dermatophagoides pteronyssinus. ConclusionHDM allergens play an important role in determining the clinical severity of AD and strong APT positivity could be more meaningful clinically.

Vitamin A supplementation and BCG vaccination at birth may affect atopy in childhood: long‐term follow‐up of a randomized controlled trial

Recent evidence suggests that immunogenic interventions such as vaccines and micronutrients may affect atopic sensitization and atopic disease. We aimed to determine whether neonatal BCG vaccination, vitamin A supplementation and other vaccinations affect atopy in childhood. In Guinea-Bissau, low-birthweight infants were randomized to early (intervention) or delayed (usual policy) BCG. A subgroup was also randomly assigned vitamin A supplementation or placebo in a two-by-two factorial design. Participants were followed up at age 3-9 years. The main outcome was atopy defined as skin prick test reaction ≥3 mm. Secondary outcomes were symptoms of eczema, asthma and food allergy. Two hundred eighty-one children had valid skin prick tests performed, and 14% (39/281) were atopic. There was no significant difference in atopy between the early and delayed BCG groups (OR, 0.71; 95% CI, 0.34-1.47). Atopy was significantly reduced in children who had responded to BCG with a scar (OR, 0.42; 0.19-0.94). Vitamin A supplementation was associated with increased atopy (OR, 2.88; 1.26-6.58), especially in those who received simultaneous BCG (5.99; 1.99-18.1, P = 0.09 for interaction between vitamin A supplementation and BCG). Early vs delayed BCG was not associated with symptoms of atopic disease, but vitamin A supplementation increased odds of wheeze within the past 12 months (OR, 2.45; 1.20-4.96). There were no statistically significant effects of early vs delayed BCG on atopy or symptoms of atopic disease. Having a BCG scar was associated with reduced atopy, whereas neonatal vitamin A supplementation was associated with increased atopy. Clinicaltrials.gov NCT 01420705.

Diagnosis and frequency of work-exacerbated asthma among bakers

BackgroundWork-exacerbated asthma (WEA) is asthma worsened by workplace exposures, although the asthma is not caused by sensitizers in the work environment. ObjectivesTo evaluate the frequency of WEA in bakers reporting work-related respiratory symptoms and the usefulness of diagnostic tests in differentiating WEA from occupational asthma (OA). MethodsThe study group included 393 bakers reporting respiratory symptoms at the workplace. In all patients, questionnaire, spirometry, skin prick tests (SPTs), and evaluation of serum total and specific IgE levels were performed. Recognition of OA was based on a specific inhalation challenge test. ResultsOccupational asthma was found in 44.5% of patients, whereas WEA was recognized in 16%. The latency period was 11.2 ± 8.2 years in patients with OA vs 13.3 ± 9.7 years in those with WEA. Sixty percent of patients with OA and 50.8% of those with WEA had positive SPT reactions to common allergens; occupational SPT results were positive in 74.9% and 34.9%, respectively. Specific IgE to flours were found in 61.7% of patients with OA and 28.6% of those with WEA. In addition, OA frequently coexisted with occupational rhinitis (53.7% of patients), whereas WEA and rhinitis were found in 31.7% of patients. ConclusionWork-exacerbated asthma was diagnosed in 16% of bakers who reported allergic respiratory symptoms. The specific challenge test for occupational allergens should be performed in bakers with suspected work-related asthma, because an assessment of sensitization (SPT to occupational allergens, evaluation of specific IgE) is not specific enough to differentiate OA from WEA.

About the role and underlying mechanisms of cofactors in anaphylaxis

Anaphylaxis is the systemic and most severe presentation of type I allergy. A number of conditions were identified that modulate the onset of anaphylaxis such as co- or augmentation factors, which significantly lower the allergen dose necessary for triggering anaphylaxis. Next to physical exercise or alcohol consumption, co-administration of nonsteroidal anti-inflammatory drugs (NSAID) or concomitant infectious diseases are well-documented cofactors of anaphylaxis. Registries for anaphylaxis document a role for cofactors in about 30% of anaphylactic reactions. Some disease entities such as 'wheat-dependent exercise-induced anaphylaxis' (WDEIA) are explicitly characterized by elicitation of anaphylaxis only in the presence of at least one such cofactor. Using WDEIA as a model disease, studies demonstrated that exercise increases skin prick test reactivity to and bioavailability of the allergen. Additional data indicate that alcohol consumption and NSAID administration display similar effects. Modulation of the cellular activation threshold is another mechanism underlying cofactor-induced anaphylaxis, most likely also functional when infectious diseases orchestrate elicitation of anaphylaxis. Cofactors are increasingly accepted to play a fundamental role in eliciting anaphylaxis. Consequently, to improve patient management modalities, a better understanding of the underlying mechanisms is warranted. This review aims to update clinicians and clinical scientists on recent developments.

The effect of montelukast on wheal reactions in skin prick tests: A double-blind-placebo-controlled randomized trial

ObjectiveIt is well-known that number of drugs may interfere with wheal reactions in skin prick test. However, the effect of long-term use of montelukast, a cystenil leukotriene receptor antagonist, on skin prick test hasn’t been full elucidated. The aim of present study was to demonstrate the effect of montelukast on skin prick tests (SPT). MethodsThis is a single-center, randomized, double-blinded, placebo-controlled study including two treatment periods with a wash-out interval. The subjects received montelukast (5mg per day), fexofenadine HCl (60mg per day) and placebo (lactose) with a double-blinded manner during 7- and 21-days treatment periods with a 14 days wash-out period. Dermatophagoides farinae (D. farinae) was used as the skin test material, while histamine as positive control and normal saline as negative control. Overall, 7 skin prick tests were performed at following time points: before treatment periods, on the last days of both treatment periods, 24h after completion of treatment periods, and on the last day of 14-days interval. ResultsSixty house dust mite (HDM) allergic children (23 girls and 37 boys) with allergic rhinitis and/or asthma completed the study. Mean age was 8.3±2.0 years. In the fexofenadine group, a significant suppression was observed in post-treatment values when compared to baseline values in SPT with D. farinae (p=0.019). In the montelukast group, no significant suppression was observed in SPT with D. farinae at all time points when compared to baseline. ConclusionsOur results showed that montelukast had no effect on measurements of SPT. Thus, we concluded that there is no need to discontinue the treatment in order to perform SPT in patients receiving montelukast, even in those on montelukast treatment for at least 21 days.

Skin Reactivity to Allergens in Rabigh Area , Kingdom of Saudi Arabia

This study determined the pattern of skin prick test reactivity to allergens in patients with airway allergy residing in Rabigh Area, based on data analysis of skin prick test results. Skin prick tests of 160 Saudi attended Al Nakheel Polyclinic between July, 2012 and April, 2013. Allergen extracts set was used to test them. Out 160 patients, 114 (71%) reacted to one or more allergens, who were 73 (64%) adults and 41(36 %) children. The majority of adults (17.8%) reacted to six allergens and children (19.5%) reacted to five ones. The most frequently reacting allergen was house dust mites followed by Candida albicans then Cladosporium spp. The maximum number of positive tests per patients was 13 in adults, compared to 10 in children. A significantly higher proportion of adults were reacting to house dust mites, Aspergillus and Penicillium. Sensitivity to allergens was common in patients with airway allergy residing in Rabigh area

No effect of probiotics on respiratory allergies: a seven‐year follow‐up of a randomized controlled trial in infancy

Supplementation with the probiotic Lactobacillus reuteri reduced the incidence of IgE-associated allergic disease in infancy. This treatment might therefore also reduce the risk of asthma and allergic rhinoconjunctivitis in school age. To evaluate whether perinatal and infant supplementation with L. reuteri reduced the prevalence of respiratory allergic disease in school age and to explore whether this supplementation was associated with any long-term side effects. A randomized, placebo-controlled trial with oral supplementation with L. reuteri ATCC 55730 (1 × 10(8) CFU) during the last month of gestation and through the first year of life comprising 232 families with allergic disease, of whom 184 completed a 7-yr follow-up. The primary outcomes at 7 yr of age were allergic disease and skin prick test reactivity (ClinicalTrials.gov ID NCT01285830). The prevalence of asthma (15% in the probiotic vs. 16% in placebo group), allergic rhinoconjunctivitis (27% vs. 20%), eczema (21% vs. 19%) and skin prick test reactivity (29% vs. 26%) was similar in the probiotic and placebo group. Growth indices and gastrointestinal symptoms were similar in the two groups. No severe adverse events were reported. The effect of L. reuteri on sensitization and IgE-associated eczema in infancy did not lead to a lower prevalence of respiratory allergic disease in school age. Thus, the effect of L. reuteri on the immune system seems to be transient. Administration of L. reuteri during the last weeks of gestation and in infancy was not associated with any long-term side effects.

Peanut-specific IgE antibodies in asymptomatic Ghanaian children possibly caused by carbohydrate determinant cross-reactivity

BackgroundThe prevalence of peanut allergy has increased in developed countries, but little is known about developing countries with high peanut consumption and widespread parasitic infections.ObjectiveWe sought to investigate peanut allergy in Ghana.MethodsIn a cross-sectional survey among Ghanaian schoolchildren (n = 1604), data were collected on reported adverse reactions to peanut, peanut sensitization (serum specific IgE and skin reactivity), consumption patterns, and parasitic infections. In a subset (n = 43) IgE against Ara h 1, 2, 3, and 9 as well as cross-reactive carbohydrate determinants (CCDs) was measured by using ImmunoCAP. Cross-reactivity and biological activity were investigated by means of ImmunoCAP inhibition and basophil histamine release, respectively.ResultsAdverse reactions to peanut were reported in 1.5%, skin prick test reactivity in 2.0%, and IgE sensitization (≥0.35 kU/L) in 17.5% of participants. Moreover, 92.4% of those IgE sensitized to peanut (≥0.35 kU/L) had negative peanut skin prick test responses. Schistosoma haematobium infection was positively associated with IgE sensitization (adjusted odds ratio, 2.29; 95% CI, 1.37-3.86). In the subset IgE titers to Ara h 1, 2, 3, and 9 were low (<1.3 kU/L), except for 6 moderately strong reactions to Ara h 9. IgE against peanut was strongly correlated with IgE against CCDs (r = 0.89, P < .0001) and could be almost completely inhibited by CCDs, as well as S haematobium soluble egg antigen. Moreover, IgE to peanut showed poor biological activity.ConclusionsParasite-induced IgE against CCDs might account largely for high IgE levels to peanut in our study population of Ghanaian schoolchildren. No evidence of IgE-mediated peanut allergy was found.

Increase in sensitization to common airborne allergens among adults - two population-based studies 15years apart.

BackgroundStudies on time trends of allergic sensitization among adults are rare. The aim of the study was to compare the prevalence of allergic sensitization to common airborne allergens among adults 15 years apart and to identify risk factors for allergic sensitization.MethodsClinical examinations including skin prick test (SPT) and structured interviews were performed in two random population samples in 1994 and 2009. Furthermore, specific IgE was analyzed in 2009. SPT data were available for 483 subjects in 1994 and for 463 subjects in 2009 in ages 20–60 years. Specific IgE was analyzed in 692 subjects in ages 20–79 years.ResultsSensitization to cat (16% to 26%, p < 0.001), dog (13% to 25%, p < 0.001), birch (13% to 18%, p = 0.031) and timothy (12% to 21%, p < 0.001), based on SPT, increased significantly from 1994 to 2009. Sensitization to any positive SPT increased from 35% to 39%, p = 0.13.The proportion of having ≥3 positive SPT reactions increased from 40% to 56%, p = 0.002. The sensitization pattern yielded similar results based on specific IgE. Risk factors for allergic sensitization were having a family history of allergy (OR 3.1, 95% CI 2.0-4.8 for any positive SPT; OR 2.7, 95% CI 1.8-4.0 for any elevated IgE) and urban living (OR 1.7, 95% CI 1.0-2.7; OR 1.5, 95% CI 1.0-2.4).ConclusionsThe prevalence of allergic sensitization to major airborne allergens as well as multi-sensitization increased significantly between the study years. Young age, a family history of allergy and urban living were significant risk factors for allergic sensitization.

Evaluation of Autologous Serum Skin Test and Skin Prick Test Reactivity to House Dust Mite in Patients with Chronic Spontaneous Urticaria

BackgroundChronic spontaneous urticaria (CSU) is a common skin disorder with etiology that is not well understood.MethodsIn this study, we evaluated the prevalence of autologous serum skin test (ASST) and skin prick testing (SPT) to house dust mite (HDM) in 862 CSU cases in China. Clinical features, courses and treatment responses were also recorded.ResultsThe prevalence of positive ASST was 46.3%, and patients aged 30–39 years had the highest positive rate (52.1%). Positive SPT to HDM was seen in 153 patients (17.7%) with the highest positive rate (34.2%) in patients aged 20 or less. Patients with positive ASST had higher urticaria activity scores (UAS) (4.18±0.65 vs. 3.67±0.53) but lower positive rates of HDM (24.6% vs. 37.6%), as compared with those with negative ASST (odds ratio (OR) 1.84, 95% CI 1.38–2.47). Patients could be categorized into four groups based on the results of ASST and SPT to HDM and patients with positive ASST and positive SPT to HDM had the highest disease activity scores, experienced higher frequencies of angioedema, diseases duration, and required higher dosage of loratadine every month, compared with other subgroups (P<0.0001).ConclusionsPatients with CSU showed varied responses of positive ASST and varied sensitivity to HDM, Patients with positive ASST and/or positive SPT had more disease activity compared with patients with negative ASST and/or negative SPT. Further classification can be made based on the result of SPT and ASST.

MicroRNA profiles in nasal mucosa of patients with allergic and nonallergic rhinitis and asthma

Rhinitis and asthma commonly coexist and are often regarded as "unified airways disease." Evidence exists that microRNAs are important in controlling inflammatory processes, but little is known about their role in airway inflammation. The present study evaluated the inflammatory profiles of patients with allergic rhinitis (AR), with and without concomitant asthma, and of patients with nonallergic rhinitis (NAR). We analyzed inflammatory cells, cytokines, and microRNAs from nasal biopsies and measured nasal nitric oxide (nNO) levels in 159 young adult subjects subdivided into 4 groups: (1) AR; (2) AR+asthma; (3) NAR; and (4) controls. We observed the upregulation of T-helper 2 (Th2) cytokines and the trend of elevation of nNO levels in AR patients compared to controls. Subjects with current AR symptoms had increased levels of miR-155, miR-205, and miR-498, but reduced levels of let-7e. In addition, patients with positive skin prick test (SPT) reactions exhibited increased miR-155 and miR-205 expression and a decreased level of let-7e, compared to subjects with negative SPT findings. Concomitant asthma had little effect on the inflammatory profile of AR. No significant changes in inflammatory markers were found in NAR patients compared to healthy controls. Our results suggest that microRNAs miR-155, miR-205, miR-498, and let-7e may be important in the allergic inflammation present in nasal mucosa. Regarding NAR, our findings support the view that mechanisms other than inflammation are pivotal.

The development of TH2 responses from infancy to 4 years of age and atopic sensitization in areas endemic for helminth infections

BackgroundHelminth infections and allergies are associated with TH2 responses. Whereas the development of TH2 responses and allergic disorders in pediatric populations has been examined in affluent countries, no or little data exist from low income regions of the world.The aim of this study is to examine factors influencing the development of TH2 responses of children born in areas endemic for helminth infections and to relate these factors to atopic sensitization at 4 years of age.MethodsData were collected from pregnant mothers on helminth infections, education and socioeconomic status (SES). Total IgE, IL-5 in response to mitogen, and helminth antigens were measured in children at 2, 5, 12, 24 and 48 months of age. Skin prick testing (SPT) and allergen-specific IgE were determined at 4 years of age.ResultsStrong TH2 responses were seen at 5 months of age and increased with time. Although maternal filarial infection was associated with helminth-antigen specific TH2 responses, it was low maternal education or SES but not helminth infection, which was associated with the development of high total IgE and PHA-induced IL-5. At 4 years of age when allergen reactivity was assessed by SPT, the high general TH2 responses did not translate into higher prevalence of SPT. The risk factor for SPT reactivity was low maternal education which decreased the risk of SPT positivity to allergens (adjusted OR, 0.32; 95% CI, 0.12 – 0.87) independently of maternal filarial infection which tended to reduce the child’s risk for being SPT positive (adjusted OR, 0.35; 95% CI, 0.07 – 1.70).ConclusionsIn areas endemic for helminths, potent TH2 responses were seen early in life, but did not translate into a higher SPT reactivity to allergens. Therefore, in many parts of the world TH2 responses in general and IgE in particular cannot be used for diagnosis of allergic diseases.

Allergic rhinitis is often undiagnosed and untreated: results from a general population study of Danish adults

A few earlier studies have indicated that allergic rhinitis (AR) is underdiagnosed and undertreated. To assess awareness, diagnosis and treatment of AR in a general population of Danish adults. Between October 2007 and June 2008, a total of 1277 consecutive participants in a Danish general population study of 18- to 69-year olds were skin-prick-tested and asked about respiratory symptoms. AR was defined as a combination of self-reported rhinitis symptoms and skin-prick test reactivity against inhalant allergens. Participants reporting rhinitis symptoms completed an additional questionnaire on medication for rhinitis symptoms. The prevalence of AR was 23.1%. A total of 43.6% (n = 122/280) of persons with AR had not received any treatment in the previous 12 months, and only 56.6% (n = 163/288) had been given a diagnosis of hay fever by a doctor. Both AR and lower airway symptoms indicating more severe AR were reported in 48.5% (n = 143/295). These persons were significantly more likely to having received treatment in previous 12 months and a diagnosis of hay fever. Our results support that even in an affluent country like Denmark, AR is often undiagnosed and untreated. There appears to be a need for increased awareness of AR with regard to both diagnosis and treatment.

The Effect of Three-Monthly Albendazole Treatment on Malarial Parasitemia and Allergy: A Household-Based Cluster-Randomized, Double-Blind, Placebo-Controlled Trial

BackgroundHelminth infections are proposed to have immunomodulatory activities affecting health outcomes either detrimentally or beneficially. We evaluated the effects of albendazole treatment, every three months for 21 months, on STH, malarial parasitemia and allergy.Methods and FindingsA household-based cluster-randomized, double-blind, placebo-controlled trial was conducted in an area in Indonesia endemic for STH. Using computer-aided block randomization, 481 households (2022 subjects) and 473 households (1982 subjects) were assigned to receive placebo and albendazole, respectively, every three months. The treatment code was concealed from trial investigators and participants. Malarial parasitemia and malaria-like symptoms were assessed in participants older than four years of age while skin prick test (SPT) to allergens as well as reported symptoms of allergy in children aged 5–15 years. The general impact of treatment on STH prevalence and body mass index (BMI) was evaluated. Primary outcomes were prevalence of malarial parasitemia and SPT to any allergen. Analysis was by intention to treat. At 9 and 21 months post-treatment 80.8% and 80.1% of the study subjects were retained, respectively. The intensive treatment regiment resulted in a reduction in the prevalence of STH by 48% in albendazole and 9% in placebo group. Albendazole treatment led to a transient increase in malarial parasitemia at 6 months post treatment (OR 4.16(1.35–12.80)) and no statistically significant increase in SPT reactivity (OR 1.18(0.74–1.86) at 9 months or 1.37 (0.93–2.01) 21 months). No effect of anthelminthic treatment was found on BMI, reported malaria-like- and allergy symptoms. No adverse effects were reported.ConclusionsThe study indicates that intensive community treatment of 3 monthly albendazole administration for 21 months over two years leads to a reduction in STH. This degree of reduction appears safe without any increased risk of malaria or allergies.Trial RegistrationControlled-Trials.com ISRCTN83830814

Environmental conditions, immunologic phenotypes, atopy, and asthma: New evidence of how the hygiene hypothesis operates in Latin America

It has been proposed that improved hygiene and reduced experience of infections in childhood influences the development of allergic diseases. The mechanisms by which the hygiene operates are not well established but are underpinned by two apparently incompatible immunologic paradigms, the balance of TH1 versus TH2 cytokines and IL-10-mediated regulation of TH2 cytokines. This study defined immunologic phenotypes with the use of latent class analysis and investigated their associations with environmental factors, markers of allergy and asthma, in a Latin American population. We studied 1127 children living in urban Brazil. Data on wheeze and environmental exposures were collected with standardized questionnaires. Atopy was measured by specific IgE in serum and skin prick test reactivity to aeroallergens. Cytokines were measured in culture after the stimulation of peripheral blood leukocytes with mitogen. Infections with pathogens were assessed by serology and stool examinations. Children were classified as having high or low burden of infection. Latent class analysis was used to identify immune phenotypes on the basis of cytokine production. Logistic regression was used to evaluate the adjusted effects of environment and burden of infection on the immunologic phenotypes and the effect of the phenotypes on atopy and asthma. Three phenotypes were identified, labeled underresponsive, intermediate, and responsive. Children of more educated mothers, living in improved environmental conditions, and with a low burden of infection were significantly more likely to have the responsive phenotype. The responsive phenotype was significantly associated with an increased prevalence of atopy but not asthma. Our findings contribute to a better understanding of the immune mechanisms by which the hygiene hypothesis operates in urban Latin America.