Claude MOLINA & Franz MARRACHE
1. Postmenopausal hormone therapy (MHT) and asthma :
2. Egg allergy and flu vaccine
3. Bronchial hyperreactivity and menstrual cycle
4. Cow’s milk allergy in pediatrics and constipation
5. Skin prick testing and beta-blockers (BB) ?
Postmenopausal hormone therapy (MHT) and asthma:While MHT has been proven to be the cause of delayed onset of cancers, particularly breast cancers, the risk of asthma onset is more rarely reported. The very important epidemiologic study carried out by the French INSERM team within a teaching population (Mutuelle Generale de l’Education Nationale) of women patients monitored prospectively between 1990 and 2002, throws new light on this issue (I.Romieu et al : Thorax on line 8th February 2010).
The characteristics of this cohort of women, free of asthma at menopause and following a hormone replacement therapy of oestrogen alone or combined oestrogen-progestagen, were surveyed twice a year through a questionnaire : age, treatment start and end dates, type of menopause (surgical by hysterectomy or medical), smoking habits, atopy history, all this data was submitted to a Cox model-based statistical analysis.
Among 57 664 women, representing 495 448 years of follow-up, 569 incident cases of asthma were identified (as defined per the American Thoracic Society’s criteria). The risk is significantly higher in so-called ‘recent’ users (who stopped the treatment less than a year and a half before), and in users of oestrogen alone, but also in never-smokers and patients reporting allergic disease prior to asthma onset.
A marginal increase in risk among patients using oestrogen/progestagen was also observed.
Finally, and after having tried to explain both the pro and anti-inflammatory acting mechanisms of female hormones, as well as tobacco’s anti-oestrogen effect, the authors conclude this excellent study by repeating that oestrogen treatment is associated with an increased risk of asthma onset.
Key-words: Hormone Replacement Therapy ; Asthma; Oestrogens; Progestagen
Egg allergy and flu vaccine:What attitude should be adopted when, during an influenza epidemic such as the recent H1N1 one, a vaccine is offered to a truly egg-sensitive subject, knowing the anaphylactic risks that this subject bearing the corresponding IgEs could run, if injected with a vaccine including small quantities of egg proteins? (J.M.Kelso JACI 2010 125 Avril 800-802).
Specialised publications reveal that in 1976, in the USA, out of 48 million vaccinated people there were 11 cases of anaphylaxis but none of them were egg allergic, and that between 1900 and 2005, out of 747 million doses of vaccine, 4 deaths could be related to anaphylaxis (without any details on the exact nature of these accidents). By comparison, during the same period, there were 540 000 deaths due to the viral infection, of which a great number could have been avoided. Finally, only 1 single death could be linked to egg allergy in 1969 after receiving anti-flu vaccine, again with few details on the reported case.
Concerning the administration technique and the few minimal incidents reported among subjects vaccinated despite their egg allergy, the study by James et al 1998 J.Pediatr.624-628) reveals that in 83 cases, concerning adults and children from age 1 to age 46, the preliminary injection of 10% of the dose caused for 3 subjects a reaction of irritated airway which decreased in 30 minutes, the injection of the remaining 90% being perfectly tolerated. Besides, the quantity of ovalbumin the subjects were able to tolerate without problems was close to the threshold of 1.2µg/ml or less, which renders useless both prick-tests prior to vaccination and the 2-shot vaccine method.
It is reassuring to observe with an independent study on 2009-2010 H1N1 vaccine batches that the ovalbumin rates discovered in the world’s major lab preparations were distinctly below those thresholds.
Indeed when a patient presents a preliminary reaction to an anti-flu vaccine, it is possible to suspect the responsibility of another vaccine constituent (such as the thimerosal used as a preservative and which is in fact prohibited for young children and pregnant women). Moreover, nasal administration, despite its low content of egg protein, has not proven efficient and is not recommended for asthmatics, who are often simultaneously egg allergic.
In conclusion, by taking a number of elementary precautions (vaccination by competent staff, appropriate equipment, 30 minute monitoring after the injection), an anti-flu vaccine with less ovalbumin than that the 1µg/0,5ml threshold, can be administrated without risk to an egg allergic person, without hindering the vaccine’s positive effect on the general morbidity and mortality rates due to influenza viruses.
Key-words: egg allergy; influenza virus vaccine; H1N1 virus
Bronchial hyperreactivity and menstrual cycle:Hormonal influence on asthma onset and evolution in women is clinically well known, whether it concerns puberty, pregnancy or the menstrual cycle, but its evolution is extremely inconsistent, either positive or negative according to publications.
That is why the Swiss authors (J.Dratva et al JACI 2010 125 823-829), looking for objective parameters, have tried to specify the role of hormones on the bronchial physiology of healthy subjects, by addressing a cohort of young women from their well-known cohort (SAPALDIA : Study on Air Pollution And Lung Disease In Adults) examining modifications of bronchial
hyperreactivity (BHR) in relation to the menstrual cycle and to use of oral contraceptives.
Out of the 4 180 women in the cohort, and after exclusions for various reasons, 1 482 filled in the appropriate questionnaire, but only 571, aged 28 to 58, were considered as fitting the criteria for the study, which includes respiratory functional tests (CV, FEV1), metacholine challenge and information on the menstrual cycle. The authors defined a risk window of 3 days before and 1 day after the first day of menstruation. All data were statistically analysed (logistical and linear regression analyses).
The resulting prevalence of BHR was 13% (fall of ?20% in FEV1 up to a maximal cumulative dose of 2mg of metacholine), and 6% had asthma. Besides, 143 patients underwent the metacholine test within the ‘risk window’ and a significant increase in BHR was observed during that period (odds ratio [OR], 2.3; 95% CI, .27-4.29).
Moreover, taking into account the use of oral contraceptives by 130 patients, the study revealed a weaker OR for asthma-free subjects, but a ?1 OR with patients using contraceptives whose protection against BHR is confirmed.
In conclusion, women, even asthma-free, show a cyclical variation of BHR in the perimenstrual period which must be taken into consideration to adjust treatment in case of asthmatics. The protective influence of oral contraceptives on that BHR should also be noted.
Key-words: bronchial hyperreactivity; menstrual cycle; oral contraceptives
Cow’s milk allergy in pediatrics and constipationConstipation is responsible for 3-5% of physician visits by children. It is associated with painful defecation, perianal erythema or eczema, anal fissures, and painful fecal retention thus aggravating constipation. M. A. El-Hodhod et al have aimed to evaluate the role and place of cow’s milk allergy (CMA) and the appropriate timing of tolerance in such patients : Cow’s milk allergy related pediatric constipation: Appropriate time of milk tolerance. Pediatr Allergy Immumol 2010: 21: e407–e412.
60 new-borns and young children suffering from chronic functional constipation were enrolled in the study : 27 of whom did not respond to 2-month laxative therapy (G1). 30 other healthy matching subjects were studied as a control group (G2). IgE to cow milk (CM) proteins was measured ; CM and dairy products were withdrawn for 1 month then followed by progressive CM re-challenge over 2 weeks. On the basis of their responses, subjects were classified into allergic responders (R+) and non allergic responders (R-), respectively 21 and 6 patients.
Within this group of new-borns and young children with chronic constipation, CMA was found in 77.7% cases, i.e. more than 2 out of 3, with serum specific IgEs significantly higher than in non allergic healthy or chronically constipated subjects. Besides, 22.2% of these children will become tolerant to CM after 6 months of removal and 88.8% after 12 months.
Thus, although the study was limited, CMA appears for these authors to be a significant etiologic factor for constipation in infants and young children. Serum levels of IgE to CM proteins are helpful although not definitive for diagnosis. Moreover, CM tolerance is better achieved after 12 months’ elimination.
Key words: Cow milk allergy, constipation,
Skin prick testing and beta-blockers (BB)?The use of BBs is a problem for allergic subjects because they may increase the occurrence and the severity of a possible anaphylactic reaction and complicate treatment. They are considered to be responsible for an increase in synthesizing and liberating the mediators of anaphylaxis, as well as a rise in the targeted organs’ response. Hence, the restrictions, even the contraindications pronounced as to their prescription with atopic subjects, notably during a specific immunotherapy. (cf. on the same topic our March 2005 and April 2008 Bibliographic Updates)
Aware of those risks, Irene N Fung et Harold L Kim (Skin prick testing in patients using beta-blockers: a retrospective analysis, Allergy, Asthma & Clinical Immunology 2010, 6) nevertheless wondered if such a veto was justified for allergy skin prick testing, no anaphylactic accident having been reported hitherto.
From patients consulting between 2004-2008 they selected all those who were using BBs and had undergone allergy skin tests (STs), prick tests and/or intradermal reactions. Out of the 191 subjects identified, 72 had positive results on skin tests for various allergens: environmental aeroallergens, hymenoptera venoms, food allergens, drug allergens (penicillin), latex, associated with clinical reactions concerning airways (rhinitis and/or cough, asthma) or skin (angio-oedema, rash, urticaria), and anaphylactic reactions which were either drug or food induced.
As for the diseases justifying the use of BBs, they were mainly cardiovascular (arterial hypertension, coronary arteritis, myocardial infarction history, arrhythmia), or ocular (glaucoma).
The BBs were prescribed by oral or ocular intake.
In fact, no incident or accident was observed during the skin tests.
In the light of these results, the authors consider that skin tests on atopic patients taking BB medications are harmless. They observe, in passing, that when lethal accidents occurred during immunotherapy between 1964 and 2001 as reported by the American Academy of Allergy and Immunology (AAAI), BBs were not involved.
Key words: Beta Blockers, anaphylaxis, skin tests
Source: CEFCAP
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