Andrew B. Murray

The effect of cigarette smoke from the mother on bronchial responsiveness and severity of symptoms in children with asthma

The effect of parental smoking was assessed in 94 consecutively observed children, aged 7 to 17 years, who had a history of asthmatic wheezing. The 24 children whose mothers smoked, when they were compared with children whose mothers did not smoke, had 47% more symptoms, a 13% lower mean FEV1 percent, a 23% lower mean FEF25-75%, and fourfold greater responsiveness to aerosolized histamine. A dose response was evident. There was a highly significant correlation between the results of the tests and the number of cigarettes the mother smoked while she was in the house. The differences between the children of smoking and nonsmoking mothers were greater in older than in younger subjects. The smoking habits of the father were not correlated with the severity of the childs asthma.

Airway responsiveness to histamine as a test for overall severity of asthma in children

Seventy-eight children who had a history of asthma were studied while they were symptom-free. There was a highly significant correlation between the dose of aerosolized histamine that produced a decrease in FEV1 of 20% and each of the features in the history that indicated severity of asthma. The correlation was strengthened by the combination of these features into a weighted asthma history score. None of the subjects with mildly increased bronchial reactivity had a history score of severe asthma, and none with markedly increased bronchial reactivity had mild asthma. There was also a highly significant correlation between histamine dose and the results of spirometric tests for airway obstruction. However, the correlation between asthma history score and provocative histamine dose was highly significant even in the 21 subjects who were apparently free of airway obstruction at the time of testing. Furthermore, the correlation between asthma history score and histamine dose was stronger than that between asthma score and any spirometric test, indicating that the histamine test more accurately assessed the overall severity of the asthma. Measurement of bronchial responsiveness to histamine is a useful adjunct to history in determining the severity of asthma in an individual and should be considered as an objective way of grading subjects according to severity of asthma in a clinical study.

The decrease in severity of asthma in children of parents who smoke since the parents have been exposing them to less cigarette smoke

BACKGROUND In 1985 we became aware that the smoking of parents aggravates their childrens asthma. Since then we have advised all referring doctors to urge parents not to expose their asthmatic children to smoke. METHODS We investigated 807 nonsmoking asthmatic children, from 1 through 17 years of age, who were consecutively referred between 1983 and 1990. We compared the children who were seen before July 1986 with those seen after that date. RESULTS Those seen in the later period had intimate exposure to a far smaller number of cigarettes smoked per day, both by mothers (7 vs 3, p = 0.005) and by fathers (5 2, p = 0.001). A concurrent improvement was observed in adjusted measures of asthma severity in their children (asthma score 7.5 vs 6.5, p = 0.047; forced expiratory volume in 1 second as a percent of predicted [FEV1%] 79.2 vs 93.7, p = 0.000; and forced expiratory flow rate during middle half of forced vital capacity [FEF25%-75%] 67.3 vs 82.0, p = 0.009), and for every cigarette less smoked in the room with the child the FEV1 increased by 3%. When parents of those seen in the later period were asked whether they had been told that smoke would aggravate their childs asthma, 80% affirmed that they had. The difference in asthma severity between the two time periods was much less in children of nonsmokers than in children of smokers. CONCLUSION It appears that if parents are aware that smoke will aggravate their childs asthma, the child will be exposed to fewer cigarettes, and the asthma will be less severe.

Short stature and delayed skeletal maturation in children with allergic disease

The frequency of short stature was assessed in 598 children (66% boys, 34% girls) referred consecutively because of asthma or allergic rhinitis. Six percent were of small stature, with heights of less than the third percentile for age. A total of 66 children with small stature were subsequently studied, 36 of whom had asthma. None had received steroids. Children with short stature were predominantly boys (83%, p less than 0.005) and had delayed bone age (less than 2 SD of mean, 34/45), correspondence of bone age with height age (r = 0.93), normal serum thyroxine but increased tri-iodothyronine levels (11/24), and normal insulin-induced growth hormone secretion (12/12). Their heights corresponded only in part to midparental height. The results were the same for those with and without asthma, and the severity of asthma was not related to the degree of growth retardation. The findings suggest that short stature is more common than expected in children with allergic respiratory disease, both asthmatic and nonasthmatic, that their growth potential is good, and that impaired linear growth is not necessarily a result only of asthma but of a more fundamental abnormality possibly associated with the atopic state. They emphasize the importance of considering allergic respiratory disease in the clinical evaluation of children with small stature.

The seasonal variation in a population of house dust mites in a North American city.

Mattress dust collected at monthly intervals for 2 1/2 yr was examined for mites. Both Dermatophagoides pteronyssinus and D. farinae were found. There was a significant association between the presence of live mites and the relative humidity (RH): Live mites were seen only when the RH had been greater than or equal to 50% for at least part of every day during the month of collection. There was a seasonal variation in that live mites were found only in the warmer months and not in the winter. However, the peak in the mite population was consistent neither for month nor for numbers: In 1977 a slight peak in mite numbers occurred in October, while in 1978 the peak was higher and occurred in July. Use of data from previously published studies to preduct mite levels may therefore be misleading.

The frequency and severity of cat allergy vs. dog allergy in atopic children

Questions were put to parents accompanying 1238 children, 1 to 17 yr old, who had symptoms of respiratory tract allergy. Skin prick tests were then performed. Symptoms after exposure to cats and positive skin test results from cat hair extract were significantly more frequent than symptoms after exposure to dogs or reactions to dog hair extract. The prevalence of symptoms and positive skin test reactions to cat allergens increased with age, significantly more so than the reaction or symptoms after exposure to dog allergens. The greater frequency of sensitivity to cats was not caused by exposure to cats in more homes, since dogs significantly outnumbered cats as the household pet in both atopic and nonatopic families. However, greater intimacy of exposure to cats when they were present may have been a factor because cats, significantly more often than dogs, were inside the house and in the childs bedroom. Two subgroups were examined to determine whether those with cat sensitivity who owned cats had more severe symptoms than those with dog sensitivity who owned dogs. Numbers were small and differences not statistically significant, but those in the cat subgroup more frequently had persistent allergic nasal symptoms and abnormally low spirometric measurements than did those in the dog subgroup. Our findings indicate that children are more often allergic to cats than to dogs and suggest that the greater frequency of sensitization to cats may be due to increased intimacy of exposure to cats.

It is children with atopic dermatitis who develop asthma more frequently if the mother smokes

We elicited symptoms of atopic dermatitis (AD) and of asthma from 620 children who were themselves nonsmokers, were aged 1 to 17 years, and had been consecutively referred to an allergy clinic. A histamine bronchial-challenge test revealed bronchial hyperresponsiveness in 95% of the children who had a history of wheezing or asthma and who could perform the test reliably, indicating that most of them did indeed have asthma. Children with a history of AD were much more likely to have asthma if the mother was a smoker than if she was a nonsmoker (79% versus 52%; p = 0.001). Similarly, if AD was found on examination, the percentages with asthma were 74% and 44%, respectively. By contrast, the children with no history of AD had asthma as frequently if the mother was a nonsmoker (42%) as when she was a smoker (40%). In children with AD, the prevalence of asthma was greater in both boys and girls when the mother was a smoker, but only in boys when the father was a smoker. Multiple logistic regression confirmed that the risk of asthma was greatly increased when the child had both AD and a mother who smoked.

Diagnosis of house dust mite allergy in asthmatic children: what constitutes a positive history?

Standardized questions were put to the parents of 530 children, referred consecutively for evaluation of asthma, to determine which features in the history were associated with house-dust mite allergy. Bronchial challenge tests performed on 19 of the children confirmed that there is a highly significant association between a positive skin prick test and a positive bronchial challenge test to Dermatophagoides farinae mite antigen. One hundred and eighteen (23%) of the children had positive prick tests to the mite. There is a highly significant association between a positive prick test to mite and a history that the subjects respiratory symptoms become worse when there is exposure to domestic activity that stirs up house dust (vacuuming, dusting, sweeping, making the bed, or shaking out blankets) or that the symptoms improve when out of doors. Seasonal variation and other features in the history are of little value in distinguishing mite-sensitive from mite-insensitive asthmatics. Although the 4% whose only positive prick test reaction was to mite had significant worsening of asthma during the colder months compared with the remainder, most mite-positive subjects had multiple allergies and had no characteristic seasonal pattern. The presence of a positive prick test to mite was not associated with aggravation of asthma either at night in bed or in the morning on awakening. A history similar to that of mite-sensitive subjects was elicited in those with a positive prick test to house dust. A positive history of house dust or house-dust mite allergy in asthmatics is one in which respiratory symptoms become worse during domestic activity that stirs up house dust or improve when outdoors.

The epidemiologic relationship of clinical nasal allergy to eosinophils and to goblet cells in the nasal smear

Abstract Three hundred and fifty-four Vancouver primary school children were studied. Half had a hearing loss and half were control subjects with normal hearing. A trained nonmedical interviewer presented a precoded questionnaire of allergy symptoms to their mothers, and a pediatric allergist examined the childrens noses for signs of allergy. Two nasal smears were made from each and were numbered consecutively. One was stained by Hansels and the other by Papanicolaous method. A technician scored the former positively if there were 10 eosinophils per high power field in any 2 high power fields and the latter positively if 6 goblet cells were found in the entire slide. There was a highly significant association between clinical evidence of nasal allergy and a nasal secretion eosinophilia. No significant association could be found between clinical evidence of nasal allergy and goblet cells or between eosinophils and goblet cells. The presence of goblet cells does not appear to help in making the diagnosis of nasal allergy in children.

The association of incisor protrusion with digit sucking and allergic nasal itching

Abstract Children rub their noses to relieve the itching of allergic rhinitis. The associated itching of the palate may be relieved by rubbing or by sucking a digit. Digit sucking is said to be a cause of incisor protrusion (excess overjet). A team comprised of a pediatrie allergist, an otolaryngologist, a technician, and an interviewer studied 354 Vancouver primary school children. One year later their mothers were requestioned by another interviewer. There was no increase in the prevalence of incisor protrusion in children with a stuffed nose or with enlarged adenoids. Digit sucking on its own doubled the prevalence of protrusion. When, in addition to digit sucking there was evidence of allergic itching, the prevalence of protrusion was increased about five times (statistically significant). Evidence of allergic itching alone did not increase its prevalence. Digit sucking is clearly related to incisor protrusion. It is postulated that allergic palatal itching is a stimulus for increased digit sucking in children with this habit, resulting in more incisor protrusion.