The use of mutually exclusive categories for atopic sensitization: a contrasting effect for family size on house dust mite sensitization compared with ryegrass sensitization

Allergic rhinitis in children

Allergic rhinitis affects up to 40% of children but is commonly undiagnosed. Careful assessment of nasal symptoms allows for the most appropriate therapeutic options to be chosen. Allergen avoidance is often difficult in practice. Antihistamines are of limited benefit in allergic rhinitis caused by house dust mite and other perennial allergens, where symptoms, predominantly nasal obstruction, are not histamine mediated. In contrast, symptoms triggered by pollen, such as nasal itch, rhinorrhoea and sneezing, are relieved by antihistamines. Intranasal steroids are the treatment of choice for persistent moderate-severe allergic rhinitis and are more effective than antihistamines for relief of nasal obstruction. Failure to respond to intranasal medications is often caused by poor compliance or inefficient use of nasal sprays. Immunotherapy may be a useful, if expensive, option, particularly where symptoms are because of a specific pollen. The benefits of immunotherapy in house dust mite-induced rhinitis and asthma remain controversial.

Allergic rhinitis

Childhood rhinitis may be classified into non-allergic and allergic. Allergic rhinitis is further divided into seasonal and perennial. Seasonal rhinitis is a disease particularly of teenagers and young adults and appears to be less common in primary and pre school age children. In seasonal rhinitis, with relevant grass pollen sensitization, the link between the allergen exposure and rhinitis is clear cut. However, in other situations such as perennial rhinitis and house dust mite allergen sensitization, the link between symptoms and allergen exposure is less certain. Avoidance of allergens often proves to be difficult in practice. Intranasal steroids are the treatment of choice for persistent moderate-severe allergic rhinitis and are more effective than antihistamines for relief of nasal obstruction. Antihistamines are effective for control of histamine related symptoms such as itching, rhinorrhoea and sneezing. The use and benefits of sublingual or injectable immunotherapy in children are controversial.

Infant feeding and childhood atopy: does early introduction of non-milk fluids matter?

Studies on the role of non-milk fluids in the development of child atopic disease are scarce. We had a unique opportunity to investigate prospective association between the introduction of fruit syrup, orange juice, sterilized water, vitamins and honey at 1 month and the development of child atopic disease. The exposure of interest was measured by parental report of non-milk fluids introduction to infants aged 1 month at the Tasmanian Infant Health Survey, 1988-89, Tasmania. Data on the outcomes of interest (atopic sensitization, asthma, eczema and hay fever) were collected during the 1997 Childhood Allergy and Respiratory Health Study when children were 8 yr old. Relative risks were derived from generalized linear model with a log link function and binomial error structure. None of the non-milk fluids appeared to be a significant predictor of atopic sensitization. Only sterilized water was a significant risk factor for asthma (adjusted relative risk = 1.59; 95% confidence intervals: 1.14-2.22), which may be partly because of associated overall better hygienic conditions and decreased exposure to early infections in the household. In summary, we were unable to find evidence for an association between introduction of non-milk fluids in infancy and childhood atopic disease.

Latex allergy in the prehospital setting

INTRODUCTION

Latex allergy first was recognized early in the 20th Century, but was not a matter of concern until the last decade of that Century. The reported incidence of latex allergy in different occupations varies considerably. It has been documented in dental workers, operating theater staff, anesthetists, and laboratory technicians. However, little data specifically related to those involved in patient care in the emergency prehospital setting are available.

METHODS

A questionnaire was distributed to a sample of both volunteer and salaried first responders from St. John Ambulance Australia in South Australia and Western Australia, and the South Australian Ambulance Service. The first responders were surveyed to: (1) determine the incidence of latex allergy; (2) consider possible factors associated with its development; (3) compare characteristics of the surveyed groups; and (4) reinforce the development of an educational program. The study tool had predetermined statistical qualities. Data were collated and processed using standard statistical procedures. Surveys were collected anonymously.

RESULTS

Of the 2,716 forms distributed, 1,099 were returned, resulting in an overall response rate of 40.5%. Atopy was identified in 14.9% of participants, hand dermatitis in 9.4%, and latex allergy in 6.4%. In the group of full-time ambulance officers, there was a significantly higher incidence of hand dermatitis and latex allergy. There also was a significant relationship between latex allergies and both dermatitis and glove usage (as measured by frequency and duration).

CONCLUSION

In a group of first responders assessed by an anonymous, voluntary questionnaire, the subset of full-time, salaried ambulance officers was identified as having a higher incidence of hand dermatitis and latex allergy than their volunteer co-workers. These results require further assessment to substantiate the frequency of latex allergy and determine the predisposing factors. All personnel must learn about hand care. Non-powdered, natural rubber latex gloves should be supported for general use in this setting.

A differing pattern of association between dietary fish and allergen-specific subgroups of atopy

BACKGROUND

We examined the role of fish intake in the development of atopic disease with particular reference to the possibility of differential effects on allergen-specific subgroups of sensitization.

METHODS

The exposure of interest was parental report of fish intake by children aged 8 years at the 1997 Childhood Allergy and Respiratory Health Study (n = 499). The outcomes of interest were subgroups of atopy: house dust mite (HDM)-pure sensitization [a positive skin-prick test (SPT) > or = 2 mm to Der p or Der f only], ryegrass-pure sensitization (a positive SPT > or = 2 mm to ryegrass only); asthma and hay fever by allergen-specific sensitization.

RESULTS

A significant association between fish intake and ryegrass-pure [adjusted odds ratio (AOR) 0.37 (0.15-0.90)] but not HDM-pure sensitization [AOR 0.87 (0.36-2.13)] was found. Fish consumption significantly decreased the risk for ryegrass-pure sensitization in comparison with HDM-pure sensitization [AOR 0.20 (0.05-0.79)].

CONCLUSIONS

We have demonstrated a differential effect of fish intake for sensitization to different aeroallergens. This may be due to the different timing of allergen exposure during early life. Further investigation of the causes of atopic disease should take into account allergen-specific subgroups.