The prevalence of immediate positive skin tests in Nepalese children

The burden of asthma in children: an Asian perspective

A worldwide increase in the prevalence of asthma has been reported in recent years. With an increase in prevalence comes an increased burden of disease in terms of morbidity, mortality and compromised quality of life. The economic burden in terms of utilisation of healthcare resources and limitation of the earning capacity of the individuals and families is an added problem. Various indicators such as disability-adjusted life years and healthy life years have been used to define the economic burden. The data from Asian countries regarding these parameters is scarce, underlining the need for systematic studies in these countries, especially those that are resource poor. The purpose of this review is to highlight the varying prevalence of asthma in Asia and to assess the likely economic burden for the future.

Prevalence of atopy in students from Málaga, Spain

BACKGROUND

Epidemiologic studies are necessary to determine the prevalence of allergic diseases. This varies widely depending on allergen preparations and patients studied.

OBJECTIVE

To investigate the prevalence of atopic disease, skin test reactivity, total and specific IgE to common allergens, and other variables in a sample of students from Málaga, southern Spain.

METHODS

Three hundred sixty-five students (age 17.9 +/- 1.18) were interviewed by an allergist. Skin prick tests were performed with Dermatophagoides pteronyssinus, Artemisia vulgaris, Plantago lanceolata, Chenopodium album, Olea europaea, Phleum pratense, Parietaria judaica, Cynodon dactylon, Alternaria tenuis, and cat dander. Total and specific IgE to D. pteronyssinus, Olea, and Parietaria were determined.

RESULTS

Of all subjects studied, 19.9% suffered from rhinoconjunctivitis, 4.1% rhinoconjunctivitis plus asthma, 3.1% asthma alone, and 0.8% atopic dermatitis; 46.4% had a positive skin test to at least one allergen (28.2% to D. pteronyssinus, 20.4% to Olea, 13.8% to Phleum); and 43% had total IgE > 100 kU/L and 44.7% a family history of atopy. Allergic symptoms were strongly associated with skin test positivities and family allergic history. Patients with asthma or skin prick test positive had higher total IgE values than others (P < .01). There was a significant correlation between specific IgE values and wheal size in skin test.

CONCLUSIONS

Our findings confirm the high prevalence of atopic diseases, and the close relationship of skin tests reactivity (or presence of specific IgE) to allergens with symptoms of asthma and rhinitis. The presence of a family history of allergic diseases influences the development of positive skin tests and atopic illness. Dermatophagoides pteronyssinus and pollen of Olea europaea were found to be the most common allergens.

Eczema, asthma and allergy

The literature in relation to the development of atopic and allergic disorders has been reviewed, in order to assess the claim that prolonged and exclusive breast feeding protects against the development of such disorders. The data in the literature show little consistent evidence to identify any protective association between breast feeding and either eczema, wheezing/asthma or other types of atopy or allergic response.

Manifestation of allergic rhinitis in latent-sensitized patients. A prospective study

In a prospective study of allergic rhinitis in latent-sensitized young patients, 114 children were observed over a period of 4 years. At the beginning of the study, all patients were found to be sensitive to inhalant allergens but without any signs of clinical manifestations. Each patient's rhinologic and allergic status was checked in yearly follow-up examinations to determine the incidence of allergic rhinitis becoming clinically apparent and to define special risk characteristics. During the period of observation, 53% of the children developed manifest allergic rhinitis, while an additional 5% developed clinical symptoms of allergic bronchial asthma. Patients who showed monovalent sensitivity formed a special risk group, especially if they were sensitized to pollen. A continuously increasing serum IgE titer, increased concentrations of specific IgE, and skin tests were used as prognostic criteria to predict imminent clinical manifestations.

Immediate hypersensitivity, IgE and asthma

Twenty-one asthmatic and twenty-two non-asthmatic children and nine asthmatic adults from two different rural areas of Tanzania, and eight asthmatic children from Dar-es-Salaam were surveyed by questionnaires, skin testing and the measurement of serum IgE. Asthma was significantly commoner in female rural children (four males, fifteen females). The rural asthmatic children apparently had less skin reactivity (in seven of nine tests) and lower specific (in two of four tests) and total serum IgE than age-, sex- and village-matched controls. This pattern of asthma in rural children in the tropics represents a different type of asthma from that found in temperate zones. In contrast, the adult rural asthmatics and the urban children seemed to have the pattern of increased skin reactivity and serum IgE found in asthmatic patients from temperate climates.

Exercise-induced asthma in Nepalese children

Three hundred and one children between 5 and 15 years old in the hills of east Nepal were studied to determine the prevalence and the main causes of asthma and atopy. Asthma was diagnosed on the basis of history, clinical examination and the results of a 6-min exercise test (step test). Asthma was diagnosed in six children, none of whom was skin prick test positive. We present here normal values of baseline peak expiratory flow rate (PEFR), and the exercise-induced changes in PEFR in normals, asthmatics, other wheezy children and others with atopic histories. The results of the skin prick tests are presented with the atopic histories in another paper.