Asthma cases in childhood attributed to atopy in tropical area in Brazil / Asma infantil atribuida a atopia en la zona tropical de Brasil

OBJECTIVE: This study aimed to explore the association between asthma and atopy in a cohort of children living in a large urban center in Brazil. Atopy was defined by the presence of allergen-specific IgE in serum or by a positive skin prick test. METHODS: In a sample of 1 445 Brazilian children, the association between the prevalence of asthma, skin prick test positivity, and allergen-specific IgE in serum was investigated. RESULTS: The prevalence of asthma was 22.6 percent. The presence of serum allergen-specific IgE was frequent in asthmatics and nonasthmatics, and the prevalence of asthma increased only with levels of allergen-specific IgE > 3.5 kilounits/L. The proportion of asthma attributable to atopy was estimated to be 24.5 percent when atopy was defined by the presence of allergen-specific IgE. With a given level of specific IgE, no association between skin test reactivity and asthma was observed. Skin prick tests were less sensitive than specific IgE for detection of atopy. CONCLUSIONS: Most asthma cases in an urban underprivileged setting in Brazil were not attributable to atopy. This observation has important implications for understanding the risk factors for the asthma epidemic in Latin America.

OBJETIVO: Explorar la relación entre el asma y la atopia en una cohorte de niños que viven en un gran centro urbano de Brasil. En este estudio, se considera atopia la detección de IgE sérica específica de algún alérgeno o un resultado positivo a la prueba de punción cutánea. MÉTODOS: Se estudió la relación entre la prevalencia del asma, el resultado positivo a la prueba de punción cutánea y la detección de IgE sérica específica de algún alérgeno en una muestra de 1 445 niños brasileños. RESULTADOS: El asma registró una prevalencia de 22,6 por ciento. La presencia de IgE séricas específicas de alérgenos fue frecuente tanto en los asmáticos como en los no asmáticos, y la prevalencia del asma fue mayor solo cuando el valor detectado de la IgE específica del alérgeno era > 3,5 kilounidades/litro. Se calculó que la atopia definida como la detección de IgE específicas de alérgenos es responsable de 24,5 por ciento de los casos de asma. No se observó ninguna relación entre la reactividad a la prueba de punción cutánea y el asma en función de los valores de IgE específicas. La prueba de punción cutánea es menos sensible que la detección de IgE específicas en lo que respecta al diagnóstico de atopia. CONCLUSIONES: La mayoría de los casos de asma que se registran en entornos urbanos desfavorecidos de Brasil no son atribuibles a atopia. Esta observación tiene implicaciones importantes en lo que respecta a la comprensión de los factores de riesgo que predisponen a la epidemia de asma en América Latina.

Controvérsias na associação entre diabetes mellitus tipo 1 e asma / Controversies in the association between type 1 diabetes and asthma

OBJETIVO: Revisão crítica da literatura sobre a associação entre asma e diabetes mellitus tipo 1 (DM1). FONTE DOS DADOS: Pesquisa bibliográfica na base de dados MEDLINE e LILACS nos últimos vinte anos. SíNTESE DOS DADOS: Muitos estudos mostram associação inversa entre asma, atopia e o risco de desenvolver DM1. De acordo com a "Hipótese da Higiene", o risco de doenças alérgicas diminui com infecções precoces na infância no sentido de afastar-se do perfil Th2, predominante ao nascimento, em direção ao fenótipo Th1. No entanto, outros trabalhos demonstram associação positiva ou ausência de associação entre DM1 e alergias. Existe a possibilidade de fatores ambientais contribuírem para ocorrência de doenças mediadas por células Th1 e Th2 no mesmo indivíduo, por provável deficiência de mecanismos imunomodulatórios mediados pela interleucina-10 e células regulatórias. CONCLUSÃO: As informações sobre a associação inversa entre doenças mediadas por resposta Th1 (por exemplo, DM1), e aquelas mediadas por resposta Th2 (por exemplo, alergias) são conflitantes, requerendo mais estudos para esclarecer esta questão.

OBJECTIVE: Critical review of the literature to investigate the relationship between asthma and type 1 diabetes mellitus (DM1). SOURCE OF DATA: Bibliography search in MEDLINE and LILACS databases in the last twenty years. SUMMARY OF DATA: Several studies demonstrate an inverse relationship between asthma, atopic diseases and the risk to develop DM1. According to the "Hygiene Hypothesis", the risk of allergic diseases decreases with infections early in childhood, towards distance of Th2 profile, common at birth, to the Th1 phenotype. Other articles described lack of association or positive association between DM1 and allergies. There is a possibility of environmental factors interfering in the development of disorders mediated by Th1 and Th2 cells, in the same individual, due to the absence of immunomodulatory mechanisms mediated by interleukin-10 and regulatory cells. CONCLUSION: The existing information about the inverse association between Th1-mediated diseases (e.g., DM1), and those that are Th2-mediated (e.g., allergies) are conflicting requiring more investigation to explain this question.

Aeroallergen sensitivity among Thai children with allergic respiratory diseases: a hospital-based study.

One hundred and twenty patients, aged 3-15 years, attending the Allergy Clinic, Thammasat University Hospital, with allergic rhinitis, asthma or both conditions were studied. Standardized skin prick tests were performed with 15 common aeroallergens. The subjects were 85 boys and 35 girls with the mean age of 8.1 years (SD = 3.4 years). There were 63 cases (53%), 22 cases (18%) and 35 cases (29%) diagnosed with allergic rhinitis only, asthma only and both conditions, respectively. The prevalence of asthma among the allergic rhinitis patients was 36 percent whereas the prevalence of allergic rhinitis among the asthmatic patients was 61 percent. The sensitization patterns for major aeroallergens among the three groups were similar with the most common sensitized allergens as D. pteronyssinus, followed by D. farinae, American cockroach, Kopok and German cockroach, respectively. Among the atopic patients, a greater number of allergen reactivity was significantly associated with the increased risk of having their coexistence of allergic rhinitis and asthma (p = 0.0046; score test for trend of odds ratio).

Skin sensitization to common allergens in Turkish wheezy children less than 3 years of age.

Infants and small children with asthma are not commonly skin tested, as allergy is not considered to be a major cause of infantile asthma. The aim of this study was to determine the frequency of skin test positivity to various allergens in wheezy children less than 3 years of age. We evaluated 161 patients with infantile asthma (median age 20 months) and 100 healthy controls (median age 18 months). Infantile asthma was defined as three or more episodes of wheezing in a child less than 3 years of age, whose symptoms improved on treatment with beta-agonist and anti-inflammatory agents. All children were skin tested to house dust mites (HDM), pollens, molds, and cow milk extracts using prick technique. One hundred and eighteen (73.3%) children In the patient group tested positive to HDM, 84 (52.1%) to pollens, 37 (22.9%) to molds, and 16 (10%) to cow milk. Sensitization rates to HDM were significantly higher in the patient group than In the healthy controls. Sensitization rates to pollens were not statistically different between the two groups. There was no association between family history of atopy and frequency of sensitization to allergens in the wheezy and control groups. We concluded that skin sensitization to allergens was common In wheezy infants. The prevalence of sensitization to indoor allergens was higher than to outdoor or food allergens.

Teste de provocaçäo brônquica com inalaçäo de aspirina lisina / Bronchial provocation test with aspirin lysine inhalation

A avaliaçäo da reatividade brônquica com aspirina lisina é sugerida como método diagnóstico para pacientesasmáticos com história prévia de sensibilidade à aspirina. Com o objetivo de avaliar a eficácia e viabilidade desse teste, foram estudados 16 indivíduos com média de idade de 28 anos, divididos em dois grupos. O primeiro grupo (grupo AAS), formado por nove pacientes com história sugestiva de asma induzida por aspirina, e o segundo (grupo controle), por sete indivíduos incluídos nesse protocolo foram submetidos, no laboratório de funçäo pulmonar, a duas fases de estudo. Primeiro, ao teste de broncoprovocaçäo com histamina, e após um intervalo de no mínomo quatro dias, à medida de reatividade brônquica com aspirina lisina. No grupo AAS, todos os pacientes apresentaram broncoprovocaçäo positiva com aspirina lisina, enquanto no grupo controle os testes com aspirina foram foram negativos. A tolerância ao exame foi satisfatória, sendo o broncoespasmo, quando presente, controlado com fenoterol 'spray'. Concluímos que a broncoprovocaçäo com aspirina lisina é um método diagnóstico eficaz e seguro em pacientes asmásticos com história de sensibilidade oral à aspirina