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Biomedical subjects

Andrew Kemp

Publications and source records attributed to Andrew Kemp.

16 recordsLinked to original sources
PubMed2006

Does post-nasal drip cause cough in childhood?

The proposition that post-nasal drip (PND) is a common cause of cough in childhood is controversial. The concept of PND as a common cause of cough is derived primarily from the adult literature. The definition of what constitutes PND is variable and it is unclear whether it is a symptom, a sign or both. Examination of the specificity of symptoms and signs for the diagnosis of PND syndrome further confuses the issue. A definitive diagnosis of cough induced by PND cannot be made from history and physical examination alone. The concept is inconsistent both with the meaning of the word 'drip' and the science of rheology. The most plausible explanation for the occurrence of cough in children identified with increased post-nasal secretions is that both reflect co-existent airways pathologies. In considering causes of chronic cough in childhood, it is now time to abandon the concept of PND and the associated PND syndrome.

Adolescent↗
PubMed2006

Hypoallergenic formula prescribing practices in Australia.

AIM: To gain insight into the use of hypoallergenic formula in Australia by analysis of prescribing statistics. METHODS: Statistics on supply of amino acid and extensively hydrolyzed formula were obtained from the Health Insurance Commission web site. The number of prescriptions supplied in 2003 and 2004 per 1000 children aged 4 years and younger were calculated for each State and Territory. This was related to the numbers of paediatric physicians and paediatric allergists in each State. RESULTS: There was a marked rise in the use of amino acid formula (AAF) commencing in 2001. The Australian Capital Territory, New South Wales and Victoria had 6-7 times more AAF items per 1000 children prescribed than Western Australia. This did not appear to relate to the numbers of paediatricians or paediatric allergists in each State. In all States and Territories the prescribing of extensively hydrolyzed formula was less than that of AAF. CONCLUSIONS: There are significant regional differences which do not appear to be related to the prevalence of allergic disease. In some States and Territories AAF may be frequently prescribed as a first line treatment for cows milk allergy and for prevention of allergic disease in contradistinction to current recommendations of the Pharmaceutical Benefits Scheme and authoritative statements and position papers. Re-examination of both the Pharmaceutical Benefit Scheme guidelines and the knowledge and perceptions of the prescribing community is indicated.

Amino Acids↗
PubMed2006

Omenn syndrome: therapeutic effects of cyclosporin.

Omenn syndrome is a severe combined immunodeficiency with features of generalised erythroderma alopecia and evidence of Th2 inflammation (eosinophilia and raised IgE). We describe a differential effect of 2 calcineurin inhibitors, cyclosporine A (CsA) and tacrolimus, with CsA rapidly improving the erythroderma and lymphocytosis but tacrolimus having little effect.

Alopecia↗
PubMed2005

Exposure to infant siblings during early life and risk of multiple sclerosis.

CONTEXT: The "hygiene hypothesis" has implicated sibship as a marker of infection load during early life and suggests that exposure or reexposure to infections can influence the developing immune system. Viral infection has also been implicated in the pathogenesis of multiple sclerosis (MS). OBJECTIVES: To evaluate whether exposure to infant siblings in early life is associated with the risk of MS, and to explore the possible mechanism for any apparent protective effect, including altered Epstein-Barr virus (EBV) infection patterns. DESIGN, SETTING, AND PATIENTS: Population-based case-control study in Tasmania, Australia, from 1999 to 2001 based on 136 cases of magnetic resonance imaging-confirmed MS and 272 community controls, matched on sex and year of birth. MAIN OUTCOME MEASURE: Risk of MS by duration of contact with younger siblings aged less than 2 years in the first 6 years of life. RESULTS: Increasing duration of contact with a younger sibling aged less than 2 years in the first 6 years of life was associated with reduced MS risk (adjusted odds ratios [AORs]: <1 infant-year, 1.00 [reference]; 1 to <3 infant-years, 0.57 [95% confidence interval {CI}, 0.33-0.98]; 3 to <5 infant-years, 0.40 [95% CI, 0.19-0.92]; > or =5 infant-years, 0.12 [95% CI, 0.02-0.88]; test for trend, P = .002). A history of exposure to infant siblings was associated with a reduced IgG response to EBV among controls. Controls with at least 1 infant-year contact had a reduced risk of infectious mononucleosis and a reduced risk of very high composite EBV IgG titers (AOR, 0.33; 95% CI, 0.11-0.98) compared with other controls. The inverse association between higher infant contact and MS was independent of EBV IgG titer. CONCLUSION: Higher infant sibling exposure in the first 6 years of life was associated with a reduced risk of MS, possibly by altering childhood infection patterns and related immune responses.

Adult↗
PubMed2005

Infant sleeping environment and asthma at 7 years: a prospective cohort study.

OBJECTIVES: We investigated the role of infant bedding items, as part of a composite bedding environment, in the development of childhood wheezing. METHODS: This prospective cohort investigation involved 863 children who participated in an infant survey in 1988 and an asthma study in Tasmania, Australia, in 1995. The derived 3 composite infant bedding categories corresponded to increasing numbers of house dust mite (HDM)-rich bedding items used. Outcomes measured included recent and frequent wheezing. RESULTS: Composite infant bedding used was associated with recent wheezing. Effects increased at increasing levels of HDM-rich bedding items used. Effects were further enhanced by home environmental factors of bedroom heating, recent bedroom painting, and absence of bedroom carpeting. When any 2 or more of these environmental factors were present, a strong dose-response relationship was evident. CONCLUSIONS: Our results show that bedding exposures in infancy are prospectively associated with childhood wheezing and that home environmental conditions may modify this association.

Asthma↗
PubMed2004

The bedding environment, sleep position, and frequent wheeze in childhood.

OBJECTIVE: Synthetic quilt use has been associated with increased childhood wheeze in previous studies. Our aim was to examine whether the adverse effect of synthetic quilt use on frequent wheeze differed by usual sleep position. DESIGN, SETTING, AND PARTICIPANTS: A population-based cross-sectional study of 6378 (92% of those eligible) 7-year-olds in Tasmania, Australia, was conducted in 1995. Exercise-challenge lung function was obtained on a subset of 414 children from randomly selected schools. EXPOSURE MEASURES: Child bedding including pillow and overbedding composition and usual sleep position by parental questionnaire. OUTCOME MEASURES: Frequent wheeze (>12 wheeze episodes over the past year), using the International Study of Asthma and Allergies in Childhood parental questionnaire, and baseline and postexercise forced expiratory volume in 1 second lung-function measures. RESULTS: Frequent wheeze (n = 117) was positively associated with synthetic quilts, synthetic pillows, electric blankets, and sleeping in a bottom bunk bed but did not vary by sleep position. In a nested case-control analysis, the association between synthetic quilt use and frequent wheeze differed by sleep position. Among children who slept supine, synthetic (versus feather) quilt use was associated with frequent wheeze (adjusted odds ratio: 2.37 [1.08, 5.23]). However, among nonsupine sleepers, overlying synthetic quilt use was not associated with frequent wheeze (adjusted odds ratio: 1.06 [0.60, 1.88]). This difference in quilt effect by sleep position was highly significant. Similarly, synthetic quilt use was associated with lower postexercise forced expiratory volume in 1 second measures among supine but not nonsupine sleeping children. CONCLUSION: An increasing focus on the bedding environment immediately adjacent to the nose and mouth is required for respiratory disorders provoked by bedding, such as child asthma characterized by frequent wheeze.

Asthma↗
PubMed2003

The General Practice Research Network: the capabilities of an electronic patient management system for longitudinal patient data.

PURPOSE: To evaluate the potential of a general practice research database derived directly from de-identified electronic medical records to provide national prescribing data in Australia. To observe the utilisation of a computer-based patient management system over time. To evaluate the impact of the research network participation on data quality in participants' electronic records. METHOD: A random sample of 297 general practitioners (GPs) from 128 practices provided longitudinal patient data from electronic medical records (using Medical Director software) retrospectively from 1 January 1999 to April 2002. The General Practice Research Network (GPRN) database contains approximately 600,000 patients, representing over 4 million prescriptions from 4 million encounters. The quality and representativeness of data for prescribing, morbidity and software usage were evaluated by comparison with National data. RESULTS: Older GPs (> 55) were under-represented, perhaps due to lower computer usage rates, but patient visits were similar to the national distribution. Over time, there were increases in: the quality of prescribing data (with reason for visit/prescription being compulsorily recorded); recording of non-prescribing visits; and the use of other features of the electronic patient management software. CONCLUSIONS: Data derived from electronic general practice records is of sufficient quality to be used to provide national prescribing estimates and has potential value for pharmacoepidemiology and population health monitoring. Such longitudinal data has previously been unavailable in Australia. Monitoring of software usage demonstrates the evolution of the Australian GP user and will be increasingly useful in assessing and improving the quality of electronic medical records.

Australia↗
PubMed2003

Immune deviation and the hygiene hypothesis: a review of the epidemiological evidence.

The epidemiological evidence for the proposal that early life immune deviation is the principal mechanism by which microbial agents prevent the development of atopy has been reviewed. Seven criteria are proposed which should ideally be fulfilled. The majority of studies only fulfill two or three criteria. For mycobacteria, measles and respiratory viruses there are studies that demonstrate a significant increase in atopy or allergic disease. Parasite infections, which provide a strong TH2 stimulus, are associated with reduced rather than enhanced allergen sensitization. The available epidemiological evidence does not provide support for a mechanism of early life immune deviation. The principal environmental influences on atopic disease are likely to occur throughout life and involve interactions between microbes and other non-infective and lifestyle factors.

Bacterial Infections↗
PubMed2003

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

Our aim was to examine the relative importance of family size on sensitization to two different allergens: ryegrass and house dust mite (HDM), using a mutually exclusive classification for allergen-specific sensitization. An 8-year follow-up birth cohort study of children born between 1988-89 was conducted. The follow-up sample consisted of 498 children residing in Northern Tasmania in 1997 (84% of eligible). Outcome measures included skin prick test (SPT) reaction to nine aeroallergens and parental questionnaire. Family size was defined as sibling number in 1997. Children with a positive SPT to either Der p or Der f house dust mite but not ryegrass were classified as HDM-exclusive (n = 84). Children with a positive SPT to ryegrass but not HDM were classified as ryegrass-exclusive (n = 43). Family size was associated with reduced ryegrass-exclusive sensitization [AOR 0.57 (0.39, 0.84) per increase in sibling number] but not HDM-exclusive sensitization [AOR 0.97 (0.77,1.23)]. The difference in the family size effect on these sensitization outcomes was significant (p = 0.02). Similarly, family size tended to be associated with reduced asthma among ryegrass-exclusive sensitized children [AOR 0.45 (0.18,1.12)] but not HDM-exclusive sensitized children [(AOR 1.46(0.80-2.65)]. Large family size was strongly associated with reduced sensitization for ryegrass allergens but not HDM allergens using mutually exclusive sensitization categories. If this difference is confirmed in other studies, the contrasting effect of family size may reflect differences between these allergens with regard to level or timing of early life exposure, differences in allergen -specific potentiation for sensitization or unidentified confounding. The use of mutually exclusive categories for allergen sensitization will assist future work on child atopic disease.

Allergens↗
PubMed2003

Synthetic bedding and wheeze in childhood.

BACKGROUND: The reasons for the increase in childhood asthma over time are unclear. The indoor environment is of particular concern. An adverse role for synthetic bedding on asthma development in childhood has been suggested by cross-sectional studies that have found an association between synthetic pillow use and childhood wheeze. Prospective data on infant bedding have not been available. METHODS: Bedding data at 1 month of age were available from an infant survey for children who were participating in a 1995 follow-up study (N = 863; 78% traced). The 1995 follow-up was embedded in a larger cross-sectional survey involving 6,378 seven year olds in Tasmania (N = 92% of eligible). Outcome measures included respiratory symptoms as defined in the International Study of Asthma and Allergies in Childhood protocol. Frequent wheeze was defined as more than 12 wheeze episodes over the past year compared with no wheeze. RESULTS: Synthetic pillow use at 1 month of age was associated with frequent wheeze at age 7 (adjusted relative risk [aRR] = 2.5; 95% confidence interval [CI] = 1.2-5.5) independent of childhood exposure. Current synthetic pillow and quilt use was strongly associated with frequent wheeze (aRR = 5.2; CI = 1.3-20.6). Substantial trends were evident for an association of increasing number of synthetic bedding items with frequent wheeze and with increasing wheeze frequency. Among children with asthma, the age of onset of asthma occurred earlier if synthetic bedding was used in infancy. CONCLUSIONS: In this cohort, synthetic bedding was strongly and consistently associated with frequent childhood wheeze. The association did not appear to be attributable to bedding choice as part of an asthma management strategy.

Asthma↗
PubMed2002

Feather bedding and house dust mite sensitization and airway disease in childhood.

Feather bedding has been inversely associated with child wheeze and also with house dust mite (HDM) allergen levels. We conducted a cross-sectional analysis of the childhood component of a birth cohort study. Our aim was to examine the relation between feather bedding and HDM sensitization and airway disease. A total of 498 children (84% of eligible) residing in Northern Tasmania in 1997 who were eligible for the Tasmanian Infant Health Survey at birth in 1988 or 1989 participated. Outcome measures included atopic sensitization to Dermatophagoides farinae or Dermatophagoides pteronyssinus allergens, spirometric lung function, and child respiratory symptoms using questions from the ISAAC study. HDM sensitization was strongly associated with frequent wheeze (more than 12 episodes of wheeze compared with no wheeze in the past year) (rate ratio [RR], 19.61; confidence interval [CI], 6.94-55.56) but only weakly associated with asthma ever (RR, 1.65; CI, 1.30-2.09). Feather quilt use was associated with reduced HDM sensitization (adjusted RR [ARR], 0.60; CI, 0.45-0.80) and also reduced frequent wheeze episodes over the past year (ARR, 0.24; CI, 0.07-0.86). The reduction in wheeze was more evident among HDM-sensitized children. These findings are consistent with the possible mechanisms for feather bedding of a reduction in initial HDM sensitization and an improvement in respiratory symptoms among HDM-sensitized children. However, prospective studies are required to fully exclude selection bias.

Air Pollution, Indoor↗
PubMedDate not supplied

Managing childhood food allergies and anaphylaxis.

BACKGROUND: Food allergies in children are becoming more common causing concern for parents, child carers, teachers and school principals. OBJECTIVE: This article aims to provide practical information on childhood food allergies and their ongoing management including assessment, prescription of self or carer administered adrenaline, emergency action plans, patient education, school based strategies, and family support. DISCUSSION: With most schools, preschools and child care centres having at least one child with food allergies, general practitioners are increasingly likely to be involved in school liaison and education, as well as caring for families with food allergic children.

Anaphylaxis↗