Non-immediate-reading skin tests and prolonged challenges in non-immediate hypersensitivity to beta-lactams in children

BACKGROUND

A minority of children reporting non-immediate reactions to beta-lactams (BLs) are allergic. Allergy workup usually includes late-reading (48-72 hours) skin tests (ST) and short (1-3 days) drug provocation tests (DPT), regardless of the chronology of the index reaction. The sensitivity of hyper-late-reading (≥6-7 days) ST and of prolonged DPT for the diagnosis of non-immediate hypersensitivity to BLs is yet to be determined.

OBJECTIVES

To establish the diagnostic values of late-reading ST and hyper-late-reading ST and of prolonged DPT in children reporting non-immediate reactions to BLs.

METHODS

Prospective assessment of children reporting non-immediate reactions to BLs with late- and additional hyper-late-reading intradermal (ID) and patch tests, and if negative, with prolonged DPT.

RESULTS

Five hundred and fifty children reporting reactions to a single or several BLs (674 suspected BLs) were included. Non-immediate hypersensitivity to BLs was diagnosed in 63 children (11.5%), reporting 66 reactions (9.8%), based on responses in ST (n = 17, 25.8%: 5 to ID, 8 to patch tests, and 4 to both tests), DPT (n = 43, 65.2%), and clinical history (n = 6, 9.1%), including 3/9 children with severe cutaneous adverse reactions. Skin test positivity was observed after the 6-7th day in 14/17 children, and DPT positivity after a median time of 3 days. No severe reaction was observed after ST or during prolonged DPT.

CONCLUSION

Additional hyper-late-reading of ST enhanced their positivity. However, their overall sensitivity remained weak, especially in non-severe cases. Prolonged DPT are safe and may improve the performance of DPT in the diagnosis of non-immediate hypersensitivity to BLs.

[Mild asthma in children: new data and a revival of interest]

According to the Global Initiative for Asthma (GINA) classification, mild asthma includes intermittent and mild persistent asthma. It represents more than 75% of asthmatic children. The symptoms and functional impact are well described. Mild asthma can lead to severe exacerbations. Progression to more severe disease may occur. Consequently, it is important to diagnose mild asthma, to initiate the appropriate treatment early, and to identify the risk factors for aggravation. Nevertheless, mild asthma is under-diagnosed and under-treated. Bronchial inflammation and remodeling are observed in mild asthma. A daily low-dose of inhaled corticosteroids is the reference treatment for mild persistent asthma. Intermittent inhaled corticosteroids cannot be recommended in children with mild persistent asthma.

Allergy to betalactam antibiotics in children: results of a 20-year study based on clinical history, skin and challenge tests

Studies based on skin and challenge tests have shown that 12-60% of children with suspected betalactam hypersensitivity were allergic to betalactams. Responses in skin and challenge tests were studied in 1865 children with suspected betalactam allergy (i) to confirm or rule out the suspected diagnosis; (ii) to evaluate diagnostic value of immediate and non-immediate responses in skin and challenge tests; (iii) to determine frequency of betalactam allergy in those children, and (iv) to determine potential risk factors for betalactam allergy. The work-up was completed in 1431 children, of whom 227 (15.9%) were diagnosed allergic to betalactams. Betalactam hypersensitivity was diagnosed in 50 of the 162 (30.9%) children reporting immediate reactions and in 177 of the 1087 (16.7%) children reporting non-immediate reactions (p<0.001). The likelihood of betalactam hypersensitivity was also significantly higher in children reporting anaphylaxis, serum sickness-like reactions, and (potentially) severe skin reactions such as acute generalized exanthematic pustulosis, Stevens-Johnson syndrome, and drug reaction with systemic symptoms than in other children (p<0.001). Skin tests diagnosed 86% of immediate and 31.6% of non-immediate sensitizations. Cross-reactivity and/or cosensitization among betalactams was diagnosed in 76% and 14.7% of the children with immediate and non-immediate hypersensitivity, respectively. The number of children diagnosed allergic to betalactams decreased with time between the reaction and the work-up, probably because the majority of children with severe and worrying reactions were referred for allergological work-up more promptly than the other children. Sex, age, and atopy were not risk factors for betalactam hypersensitivity. In conclusion, we confirm in numerous children that (i) only a few children with suspected betalactam hypersensitivity are allergic to betalactams; (ii) the likelihood of betalactam allergy increases with earliness and/or severity of the reactions; (iii) although non-immediate-reading skin tests (intradermal and patch tests) may diagnose non-immediate sensitizations in children with non-immediate reactions to betalactams (maculopapular rashes and potentially severe skin reactions especially), the diagnostic value of non-immediate-reading skin tests is far lower than the diagnostic value of immediate-reading skin tests, most non-immediate sensitizations to betalactams being diagnosed by means of challenge tests; (iv) cross-reactivity and/or cosensitizations among betalactams are much more frequent in children reporting immediate and/or anaphylactic reactions than in the other children; (v) age, sex and personal atopy are not significant risk factors for betalactam hypersensitivity; and (vi) the number of children with diagnosed allergy to betalactams (of the immediate-type hypersensitivity especially) decreases with time between the reaction and allergological work-up. Finally, based on our experience, we also propose a practical diagnostic approach in children with suspected betalactam hypersensitivity.

Asma infantil y del lactante

El asma es la enfermedad crónica más frecuente de la infancia. El diagnóstico suele ser fácil cuando se producen episodios de disnea espiratoria con sibilancias reversibles de forma espontánea o mediante el uso de broncodilatadores. Las radiografías de tórax, la exploración funcional respiratoria y el estudio alérgico constituyen el aspecto fundamental de las pruebas complementarias necesarias. El tratamiento de la crisis consiste en el uso de β2-adrenérgicos inhalados y, si es necesario, corticoides orales. El tratamiento de fondo tiene como objetivo limitar al máximo los síntomas y restaurar o mantener las funciones pulmonares normales. Se debe adaptar a la gravedad y al control de la enfermedad y los corticoides inhalados tienen un papel de elección.

17q21 variants modify the association between early respiratory infections and asthma

Single nucleotide polymorphisms (SNPs) at chromosome 17q21 confer an increased risk of early-onset asthma. The objective was to study whether 17q21 SNPs modify associations between early respiratory infections and asthma. Association analysis was conducted in 499 children (268 with asthma, median age 11 yrs) from the Epidemiological Study on the Genetics and Environment of Asthma (EGEA). The 12-yr follow-up data were used to assess persistent or remittent asthma in young adulthood. Respiratory infection before 2 yrs of age was assessed retrospectively. For the 12 17q21 SNPs studied, the odds ratios (OR) for association between infection and early-onset asthma (age at onset <or=4 yrs) were higher in carriers of risk genotypes (OR 3.42-6.36) than in noncarriers (OR 1.84-2.44; p-value for interaction 0.02-0.04 for five SNPs). Risk genotypes also increased the association between infection and childhood asthma that remits in adulthood (OR 4.84-7.16 in carriers and 1.74-2.25 in noncarriers; p-value for interaction 0.008-0.05 for 10 SNPs). In children with 17q21 risk genotypes and early-life environmental tobacco smoke (ETS) exposure, associations between infection and asthma were further enhanced. 17q21 genetic variants and early ETS exposure enhance the association between early respiratory infections and early-onset asthma and childhood asthma that remits in adulthood.

Oral food challenge in children: an expert review

Oral food challenges are indicated for the diagnosis of food allergy and the double-blind, placebo-controlled oral food challenge is considered the gold standard diagnostic method in children with suspected food allergy. This practice parameter for oral food challenges in children was prepared by a workgroup at the request of the French Society for Allergology and Clinical Immunology (SFAIC) and the French Paediatric Society for Allergology and Pulmonology (SP2A). We aimed to develop practical guidelines for oral food challenges in children for the diagnosis of suspected food allergy or the evaluation of food tolerance. We also considered the safety measures to be implemented during testing and management of the potentially serious allergic reactions that may arise during the test. The strength of the recommendations was established, using the GRADE evidence-based approach. We considered four issues: (1) the selection of children for oral food challenges (indications and contraindications); (2) the procedure used (material, where the test should be carried out, technique and management of reactions); (3) interpretation of the test and (4) consequences of the test.

Airway remodeling is correlated with obstruction in children with severe asthma

BACKGROUND

Severe asthma may involve an irreversible obstructive pattern, and structural changes in bronchial airways are believed to play a key role in this context. The aim of the present study was to compare airway remodeling in severe asthmatic children with or without obstructive pattern.

METHODS

Two groups of children with severe asthma and persistent symptoms, 5-14 years old were included, 15 with persistent obstructive pattern (group O) and 10 without obstructive pattern (group N). Persistent obstructive pattern was defined as a forced expiratory volume in 1 s (FEV(1)) less than 80% of the predicted value after a course of systemic corticosteroids and no significant improvement after bronchodilator. We examined bronchial biopsies by pathological and immunochemical methods and quantified airway smooth muscle (ASM) and mucus gland areas, reticular basement membrane (RBM) thickening, distance between ASM and RBM, muscle light chain kinase (MLCK) expression and number of vessels (CD31 expression).

RESULTS

Surface area of ASM (P = 0.009), MLCK expression (P = 0.03) and number of vessels (P = 0.0008) were increased in group O compared with group N. Distance of RBM-ASM was shorter in group O (P = 0.007). FEV(1) negatively correlated with ASM area (r = -0.6; P = 0.002), MLCK expression (r = -0.45; P = 0.02) and CD31 expression (r = -0.7; P = 0.0003), and positively correlated with the distance of RBM-ASM (r = 0.5; P = 0.007).

CONCLUSIONS

Structural abnormalities of airway remodeling are present in children with severe asthma. Only an increase in surface area of ASM and the density of the vascular network are more pronounced in children with persistent obstructive pattern, while RBM thickening is similar. These results are concordant with longitudinal studies which emphasize the precocity of bronchial obstruction.

Allergic rhinitis in children with asthma: a questionnaire-based study

BACKGROUND

Allergic rhinitis (AR) and asthma frequently coexist but has rarely been evaluated in children.

OBJECTIVE

This prospective study aimed to estimate the prevalence of AR in asthmatic children, and ascertain whether AR is a risk factor for the severity of asthma.

METHODS

The questionnaire, modified from the adult form of the score for allergic rhinitis (SFAR), was completed by 404 asthmatic children aged 3-18 years seen in the outpatient clinic between June 2005 and July 2007. Each item was assigned a number of points with a final score ranging from 0 to 17. AR and asthma were classified according to ARIA and GINA 2004 recommendations, respectively.

RESULTS

AR was diagnosed in 237 patients (58.7%). It was intermittent in 57.8% of the patients and persistent in 42.2%. A total score >or=9 was discriminant for AR (sensitivity=91.1%, specificity=95.2%, positive predictive value=96.4%, negative predictive value=88.3%, Youden's Index=0.86). The proportion of children having mild or moderate-to-severe asthma was independent of the presence of AR, 61.6% of moderate-to-severe asthmatic children and 55.4% of intermittent and mild asthmatic children having AR.

CONCLUSION

AR and asthma are frequently associated (58.7%). The SFAR adapted for children seems to be a simple and a reliable tool to detect AR in asthmatic children.

Identification of a new natural Ara h 6 isoform and of its proteolytic product as major allergens in peanut

Numerous food allergens of plant origin belong to the 2S albumin family, including peanut Ara h 2. In addition to Ara h 2, several other conglutins related to 2S albumins are present in peanut seeds. We evaluated the allergenicity of different peanut conglutins as compared with Ara h 2. Several conglutins were isolated from the kernel, i.e. Ara h 2, a new isoform of Ara h 6 and its derived product, which is likely to be naturally formed during seed processing. Enzyme allergosorbent tests performed on sera of peanut allergic patients showed that more than 94% of 47 analyzed patients had positive IgE responses to Ara h 6 isoform and to its degradation product. Skin prick tests with the new isoform of Ara h 6 led to a positive response in seven out of the eight tested patients. Both enzyme allergosorbent tests and skin prick tests showed that the reactivity of Ara h 6 was similar to, or even higher than, that of Ara h 2, suggesting that the present isoform of Ara h 6 is as allergenic as Ara h 2. In addition the IgE response to the plant processed (i.e., hydrolyzed) Ara h 6 new isoform is equivalent to the IgE response to the native isoform. The IgE immunoreactivity is mostly abrogated by chemical reduction and denaturation of Ara h 6 isoforms, which underlined the importance of tertiary structure in Ara h 6 immunoreactivity. These results, and particularly the high correlation between anti-Ara h 2 and anti-Ara h 6 IgE responses, emphasise the major role of 2S albumins in peanut allergenicity.

Incidence rate and factors related to post-bronchoalveolar lavage fever in children

BACKGROUND

Post-bronchoscopy and bronchoalveolar lavage (BAL) fever in children has been described by several authors.

OBJECTIVES

This study aimed at assessing the occurrence of fever after these examinations and associated risk factors.

METHODS

The study was performed in the Bronchoscopy Unit of Hôpital Necker-Enfants Malades, Paris, France, from June 2004 to July 2005. 148 children who underwent fiberoptic bronchoscopy and BAL, and remained in the Unit for 24 h, were included.

RESULTS

37.8% of the patients presented post-BAL fever. In the multivariate analysis of the selected factors (age, immunodeficiency, general or local anesthesia, mucosal biopsy, inflammation and suppuration at the moment of the examination, abnormal bronchoalveolar fluid cellularity and infection), only age <2 years and presence of infection remained associated with fever.

CONCLUSIONS

The occurrence of fever is a frequent event in children who underwent BAL. In order to reduce post-BAL fever, antibiotic strategies should be devised based on prospective studies assessing identification of predictive air-way infection criteria and/or rapid bacteriological result analysis.

[Environmental factors for asthma severity and allergy: results from the EGEA study]

INTRODUCTION

EGEA (Epidemiological study on the genetics and environment of asthma, bronchial hyperresponsiveness and atopy), a case control and family study including 2048 individuals, was initiated to look for environmental and genetic risk factors for asthma. A synthesis of the results obtained since 2002 on phenotypic and environmental aspects of asthma severity and allergy are presented in this article.

METHODS AND RESULTS

The results support a role for hormonal factors in asthma severity and in various allergic markers of asthma. A greater body mass index was related to a more severe asthma in women with early menarche. Associations between markers of allergy (eosinophils, IgE and atopy) and hormonal dependent events in women (premenstrual asthma, menopause and oral contraceptive use) have been found. In asthmatics, exposure to agents known to be associated with occupational asthma, active and passive smoking were associated with an increased clinical asthma severity score. The study underlines the protective role of country living and exposure to pets in early life on allergy markers in adulthood, supporting the hygiene hypothesis.

CONCLUSIONS

New hypothesis will be tested in the near future from the second stage of this survey.

Pharmacoeconomic assessment of specific immunotherapy versus current symptomatic treatment for allergic rhinitis and asthma in France

OBJECTIVES

The therapeutic benefit of specific immunotherapy (SIT) in allergic rhinitis and asthma has been endorsed by expert consensus. This study compared the cost/efficacy (C/E) of SIT with current symptomatic treatments (CST) for allergic rhinitis and asthma.

METHODS

A C/E analysis was performed using a decision tree model. The decision tree and medical and economic hypotheses were defined by a panel of experts. The perspective adopted was that of the French Social Security. The costs and efficacy of SIT and CST were compared for dust-mite and pollen allergies, in adults and children. Direct medical costs included diagnosis and follow-up, consultations, CST and SIT. End-point economic criteria were cost per stabilised patient and cost per asthma case avoided. A sensitivity analysis was performed for each model.

RESULTS

In adults, the incremental costs per asthma case avoided with injectable SIT were 393 Euro and 1327 Euro for dust-mite and pollen allergy, respectively, over a 6-year period. For sublingual SIT, the costs per asthma case avoided were 3158 Euro and 1708 Euro, respectively. In children, over a 7-year period, the incremental costs per asthma case avoided with injectable SIT were 583 Euro and 597 Euro for dust-mite and pollen allergy, respectively. For sublingual SIT the incremental costs were 3938 Euro and 824 Euro.

CONCLUSION

Compared to CST, SIT is a cost-effective treatment in pollen and dust-mite-induced allergic rhinitis and asthma. Sublingual SIT is an attractive option in pollen-induced rhinitis, particularly in children. SIT appears to be an economically relevant strategy compared to CST.

[Off-line exhaled nitric oxide measurement in children]

INTRODUCTION

The objective is to test the validity of a tool allowing an offline measurement of the fraction of expired nitric oxide (FENO). The device is a T-tube on which a pressure gauge allows the control of the expiratory flow and whose two side branches have a gauge such as the bags assembled on each one of them fill successively.

METHODS

The first phase aims to check that the sample collected in the second bag answers the criteria of analysis of NO during a single expiration and that this measurement can be delayed. The second phase aims to test the feasibility and the repeatability of the offline analysis in children.

RESULTS

The device makes it possible to stabilize the expiratory flow at 100 ml/s. The NO concentration in the second bag is stable during 6 hours. The intra measurement coefficient of variation of delayed FENO 0.1 is 7% (N = 19).

CONCLUSION

A off line measurement of the exhaled nitric oxide is reliable in asthmatic children.

[Allergic and pseudoallergic reactions to analgesics, antipyretics and non-steroidal anti-inflammatory drugs]

Antalgics, antipyretics and non-steroidal anti-inflammatory drugs (NSAIDs) are widely used, but suspected allergic reactions to these drugs are rare, especially in children. Most frequent reactions are cutaneous (urticaria, angioedema) and respiratory (rhinitis, asthma). Other reactions (anaphylaxis or anaphylactoid reactions, potentially harmful toxidermias) are rare. In a few patients, reactions may result from a specific (allergic) hypersensitivity (HS), with positive responses in prick and intradermal tests (anaphylaxis, immediate urticaria and/or angioedema) and in intradermal and patch tests (non-immediate reactions). However, most reactions result from a non-specific (non-allergic) HS (intolerance), with a frequent cross-reactivity between the various families of antalgics, antipyretics and NSAIDs, including acetaminophen (paracetamol). Based on a convincing clinical history and/or positive responses in challenge tests, intolerance to antalgics, antipyretics and NSAIDs has been diagnosed in 13 to 50% of the patients with allergic-like reactions to these drugs. Risk factors for HS to antalgics, antipyretics and NSAIDs are a personal atopy and age. In our experience, 50% of the children with allergic-like reactions to antipyretics, antalgics and NSAIDs were diagnosed intolerant to these drugs. Risk was high in children reporting reactions to NSAIDs (aspirin, ibuprofen) and lower in children reporting reactions to paracetamol. All the children intolerant to paracetamol were also intolerant to NSAIDs. In contrast, most children with NSAID intolerance were tolerant to paracetamol. A personal history of atopy and a mean age >or= 8 years were significant risk factors for intolerance to antalgics, antipyretics and NSAIDs.

Allergy to betalactam antibiotics in children: a prospective follow-up study in retreated children after negative responses in skin and challenge tests

BACKGROUND

Up to 10% of the patients in whom suspected betalactam hypersensitivity (HS) has been excluded by skin and challenge tests report suspected allergic reactions during subsequent treatments with the same or very similar betalactams. It has been suggested that the reactions may result from a resensitization induced by the challenge performed at the time of the allergological work-up. However, most patients did not undergo a second allergological work-up, to determine if the reactions resulted from betalactam HS or not.

OBJECTIVES

We aimed to determine if children diagnosed nonallergic to betalactams have tolerated subsequent treatments with the initially suspected and/or other betalactams, and, in case of a reaction, if the reaction resulted from betalactam HS.

METHODS

We sent a questionnaire concerning the clinical history of their children to the parents of 256 children previously diagnosed nonallergic to betalactams. A second allergological work-up was performed in the children reporting suspected allergic reactions during subsequent treatments with the same and/or other betalactams. Skin tests were performed with the soluble form of the suspected (or very similar) betalactams and other betalactams from the same and other classes. Skin test responses were assessed at 15-20 min (immediate), 6-8 h (semi-late) and 48-72 h (late). Oral challenge (OC) was performed in children with negative skin tests, either at the hospital (immediate and accelerated reactions), or at home (delayed reactions).

RESULTS

A response was obtained from 141 children (55.3%). Forty-eight (34%) of those children had not been treated with the betalactams for whom a diagnosis of allergy had been ruled out previously. Seven (7.5%) of the 93 children who had been treated again reported suspected allergic reactions. Skin tests and OC were performed in six of those children, and gave negative results in five children. In one child previously diagnosed nonallergic to amoxicillin associated with clavulanic acid, we diagnosed a delayed HS to clavulanic acid and a serum sickness-like disease to cefaclor. Thus, the frequency of reactions resulting from betalactam HS in children with negative skin and challenge tests is very low, and does not exceed 2.1% (2/93) if we consider that the child which refused a second allergological work-up is really allergic to betalactams.

CONCLUSION

Our results in a very large number of children show that reactions presumed to result from betalactam HS are rare in children in whom the diagnosis of betalactam allergy has been ruled out previously. Moreover, they suggest that, as shown for the initial reactions, most of the reactions during subsequent treatments are rather a consequence of the infectious diseases for whom betalactams have been prescribed than a result of betalactam HS. Finally, they suggest that the risk of resensitization by OC is very low, and do not support the notion that skin testing should be repeated in children diagnosed nonallergic to betalactams.

Sublingual immunotherapy in the treatment of children

Children with controlled intermittent mild-to-moderate asthma, controlled rhinitis and a single sensitivity may be appropriate candidates for sublingual immunotherapy (SLIT). Positive effects of SLIT may depend on initiation in early childhood and a long duration of treatment. To ensure optimum compliance, sociological, economic and familial factors should also be taken in to consideration when prescribing SLIT. Evidence from recent long-term trials indicates that SLIT interfered with the atopic march and the allergic progression from rhinitis to asthma without any severe adverse side effects. Local immune response has been seen to be blunted with SLIT, which suggests that treatment has an immunomodulatory effect. In addition, it may also decrease the risk of new sensitizations. Ongoing developments in SLIT, particularly advances in dosing and new indications, such as food allergies, will increase the use of this treatment modality in children.

Allergy to goat and sheep milk without allergy to cow's milk

BACKGROUND

Cow's milk (CM) allergy is the most frequent cause of food allergy in infants. Most children who are allergic to CM are also sensitized to whey proteins and/or to the casein fraction and many of them cannot tolerate goat's or sheep's milk (GSM) either. Conversely, the GSM allergies that are not associated with allergic cross-reactivity to CM are rare.

METHODS

Twenty-eight children who had severe allergic reactions, including anaphylaxis, after consumption of GSM products but tolerated CM products were recruited in a retrospective study. Whole casein and whey proteins were fractionated from CM and GSM. beta-Lactoglobulin and the different caseins were isolated, purified and used to perform enzyme allergosorbent tests (EAST) and EAST inhibition studies with the sera of the allergic children.

RESULTS

Clinical observations, skin prick testing and immunoglobulin (Ig)E-binding studies confirmed the diagnosis of GSM allergy without associated CM allergy. EAST determinations demonstrated that GSM allergy involves the casein fraction and not whey proteins. Cow's milk caseins were not at all or poorly recognized by the patient's IgE, while alphaS(1)-, alphaS(2)- and beta-caseins from GSM were recognized with a high specificity and affinity. In all cases, increasing concentrations of CM caseins failed to inhibit the binding of patient's IgE to sheep or goat milk caseins, whereas this binding was completely inhibited by GSM caseins.

CONCLUSIONS

The characteristics of GSM allergy differ from those of the CM allergy because it affects older children and appears later. CM products do not elicit any clinical manifestation in GSM allergic patients, whereas CM allergic patients, usually cross-react to GSM. In all the GSM allergic children, the IgE antibodies recognized the caseins but not the whey proteins. Moreover, IgE specificity and affinity was high to GSM and lower to CM caseins despite their marked sequence homology. Doctors and allergic individuals should be aware that GSM allergy requires a strict avoidance of GSM and milk-derived products because reactions could be severe after ingestion of minimal doses of the offending food.

[Prospective comparison of child asthma education in the emergency department and at scheduled follow-up consultation]

OBJECTIVES

To assess asthma control in asthmatic children attending the emergency department and to compare it with that for children with scheduled specialist follow-up.

POPULATION AND METHODS

Between September 2002 and September 2003, we included asthmatic children aged 6 to 16 years, attending the emergency department (group U) or pulmonology follow-up appointments (group C) at Necker Hospital, Paris, France. We used the Asthma Therapy Assessment Questionnaire (ATAQ), completed by the parents and children aged 10 years and over.

RESULTS

We interviewed 156 families and included 144 (92%) in the final analysis (77 in group U). The 2 groups did not differ in age, sex ratio, age at onset and asthma diagnosis and the frequency of asthma attacks. Children in group U received less daily maintenance treatment (P<0.01) but reported more severe asthma (P<0.05). They had also experienced fewer investigations for their asthma (fewer lung function tests P=0.01 and allergy tests P=0.001). The children in group C had better controlled asthma, as assessed by both the children themselves and their parents. They also had fewer problems relating to the behavior, communication and treatment control domains. The assessment of children and parents were similar in all areas except communication. The children considered their communication problems to be more serious than their parents did. Age-related differences were observed, with older children's parents having more difficulties in all domains investigated.

CONCLUSION

Clinicians should consider assessing asthma control in children attending the emergency department. There is clearly an opportunity to improve the quality of asthma education for these children. Clinicians could provide children with a written plan of action for asthma attacks and information about daily self-management. Improving communication between children, their parents and doctors should be considered a key educational project.

Hypersensitivity reactions to paracetamol in children: a study of 25 cases

BACKGROUND

Allergic-like reactions to paracetamol (acetaminophen) are rare. Paracetamol allergic and nonallergic hypersensitivity (HS) has been diagnosed in a few patients with skin and/or respiratory symptoms, immediate and accelerated urticaria, and angioedema especially. Most patients with HS to paracetamol were also hypersensitive to anti-inflammatory drugs (i.e. acetylsalicylic acid, ASA), suggesting that their reactions resulted from a nonallergic HS. However, anaphylactic reactions, and potentially harmful toxidermias, such as acute generalized exanthematic pustulosis and toxic epidermal necrolysis, have been related to specific paracetamol allergic HS, with tolerance to anti-inflammatory drugs.

PATIENTS AND METHODS

We report the results of a study performed in 25 children with suspected paracetamol HS. Diagnosis of paracetamol HS was based on a suggestive clinical history and a positive response in an oral challenge (OC) test.

RESULTS

Paracetamol HS was diagnosed in only one child (4%). In this child, a positive response to an OC with ASA diagnosed HS to anti-inflammatory drugs.

CONCLUSIONS

Our results in children agree with those of the literature, showing that paracetamol HS is rare, and is associated with HS to anti-inflammatory drugs in most patients.

Influence of thermal processing on the allergenicity of peanut proteins

Peanuts are one of the most common and severe food allergens. Nevertheless, the occurrence of peanut allergy varies between countries and depends on both the exposure and the way peanuts are consumed. Processing is known to influence the allergenicity of peanut proteins. The aim of this study was to assess the effect of thermal processing on the IgE-binding capacity of whole peanut protein extracts and of the major peanut allergens Ara h 1 and Ara h 2. Whole proteins, Ara h 1, and Ara h 2 were extracted and purified from raw, roasted and boiled peanuts using selective precipitation and multiple chromatographic steps, and were then characterized by electrophoresis and mass spectrometry. The immunoreactivity of whole peanut extracts and purified proteins was analyzed by the enzyme allergosorbent test (EAST) and EAST inhibition using the sera of 37 peanut-allergic patients. The composition of the whole protein extracts was modified after heat processing, especially after boiling. The electrophoretic pattern showed protein bands of low molecular weight that were less marked in boiled than in raw and roasted peanuts. The same low-molecular-weight proteins were found in the cooking water of peanuts. Whole peanut protein extracts obtained after the different processes were all recognized by the IgE of the 37 patients. The IgE-binding capacity of the whole peanut protein extracts prepared from boiled peanuts was 2-fold lower than that of the extracts prepared from raw and roasted peanuts. No significant difference was observed between protein extracts from raw and roasted peanuts. It is noteworthy that the proteins present in the cooking water were also recognized by the IgE of peanut-allergic patients. IgE immunoreactivity of purified Ara h 1 and Ara h 2 prepared from roasted peanuts was higher than that of their counterparts prepared from raw and boiled peanuts. The IgE-binding capacity of purified Ara h 1 and Ara h 2 was altered by heat treatment and in particular was increased by roasting. However, no significant difference in IgE immunoreactivity was observed between whole protein extracts from raw and roasted peanuts. The decrease in allergenicity of boiled peanuts results mainly from a transfer of low-molecular-weight allergens into the water during cooking.

Anaphylaxis during anesthesia: results of a 12-year survey at a French pediatric center

BACKGROUND

Following adverse reactions to anesthesia, tests are carried out to determine the mechanism of the reaction and to identify the agent responsible. No specific data are available in France concerning such skin tests in children.

METHODS

Between 1989 and 2001, we assessed hypersensitivity reactions to general anesthesia in 68 children. Thirty underwent more than one operation, for congenital malformations. Immunoglobulin (Ig)E-mediated anaphylaxis was diagnosed on skin tests combined with the clinical history.

RESULTS

Grade I, II and III reactions were observed in 20, 27 and 21 children, respectively. IgE-mediated anaphylaxis was diagnosed in 51 children: 31 (60.8%) for neuromuscular blocking agents (NMBA), 14 (27%) for latex, seven (14%) for colloids, five (9%) for opioids and six (12%) for hypnotics. Vecuronium was the NMBA causing the largest number of reactions. Cross reactivity to NMBA available in France was observed in 23 of 30 children (76%), particularly for vecuronium and atracurium or pancuronium. The estimated frequency of IgE mediated anaphylactic reactions was one in 2100 operations. Based on our results, 25 children subsequently received a different anesthetic with no adverse reaction.

CONCLUSIONS

As in adults, NMBA, then latex were responsible for most anaphylactic reactions during anesthesia. Our results confirm that skin tests with anesthetic agents are feasible and safe in children and improve the safety of subsequent anesthetic procedures.

[Practical advice for exercise-induced asthma in children: experience of the exercise training centre of Necker-Enfants malades hospital]

Now, to care exercise-induced asthma is not only to prescribe drugs. It is a global and interdisciplinary approach: the pulmonary rehabilitation, matching a therapeutic education and a physical training, with the goal of promoting a regular physical activity in the asthmatic child, achieving physiological benefits and improvement of quality of life. Getting from the experience of Necker-Enfants Malades Hospital's Training Centre, a few advises encourage the physical practice of the asthmatic child, and decrease risks of exercise-induced asthma: optimisation of treatments;progressive beginning and end of exercises; use of the diaphragmatic breathing, keeping up with the exercise; use of the ventilatory threshold (or dysponea threshold) as intensity of the aerobic training; practice of different activities promoting play and conviviality in sports and allowing the integration of sports in the daily life of the asthmatic child.

[Acute viral respiratory tract infections and childhood asthma]

Les infections virales respiratoires sont de très importants facteurs déclenchants des crises d'asthme. Chez l'enfant les études épidémiologiques les plus récentes, utilisant la PCR, leur attribuent le déclenchement de 80 à 85 % des crises, aussi bien pour les crises modérées que les crises nécessitant une hospitalisation. Le virus respiratoire syncytial et les virus parainfluenzae prédominent chez le nourrisson, les rhinovirus et le mycoplasme chez l'enfant plus grand. Les mécanismes précis de l'induction des crises d'asthme par les virus restent mal compris, toutefois de récentes études montrent une augmentation de l'activation des cellules inflammatoires dans le lavage alvéolaire. Les sujets atopiques, en dehors des périodes d'allergie, ne semblent pas avoir plus de manifestations respiratoires viro-induites que les non-atopiques. En revanche, chez le sujet asthmatique, l'infection virale aggrave les réactions immédiate et retardée de l'hypersensibilité immédiate après test de provocation allergénique, en augmentant la libération des médiateurs mastocytaires et le recrutement des éosinophiles dans les voies aériennes inférieures. Les études chez l'homme et l'animal suggèrent que la production locale de cytokines (IL4, IL8, RANTES, MIP-1a...) et l'expression accrue chez l'asthmatique de la molécule d'adhésion ICAM1 aient un rôle important pour le recrutement et l'activation des cellules de l'inflammation dans les voies aériennes. Une hypothèse, qui reste à démontrer serait que dans des situations où, comme dans l'asthme, les lymphocytes Th2 prédominent, un excès d'Il4 pourrait inhiber les CD8 cytotoxiques, les cellules NK et les Th1 et ainsi entraîner une diminution des défenses antivirales et une réaction inflammatoire broncho-pulmonaire plus sévère que chez le non-asthmatique.

[An unusual foreign body. Report of a case of subcutaneous emphysema during an asthma attack]

Pneumomediastinum is an uncommon complication after an asthma attack. The essential clinical sign is the presence of subcutaneous emphysema. In the great majority of cases, the treatment of pneumomediastinum corresponds to that of asthma, with resorption over several days. The situation is very different when the development of pneumomediastinum and subcutaneous emphysema is secondary to an aspiration syndrome.

[Inhaled treatment for asthma in practice]

The modalities of an inhaled treatment depends on the characteristics of the aerosol, on the age of the child, and mainly on the inhalatory system. Before the age of 8 years, the pressurised metered dose inhaler must be used together with a spacer device. Above this age, the use of a breath-actuated inhaler or of a dry powder inhaler can be proposed. Demonstration and educational instructions will increase the probability of compliance and efficiency of the treatment.

[What environmental measures should be taken for the treatment of atopic dermatitis in children and the prevention of other atopic manifestations?]

The association of atopic dermatitis, asthma and allergy is frequent. Hence, it is logical to imagine that eviction of the main indoor allergens (dust mites, animal danders) would have a preventive effect on the onset and progression of atopic dermatitis and the risk of asthma. Recent epidemiological studies are generally negative with regard to primary and also secondary and tertiary prevention. Only one study appeared positive; it combined eviction of food allergens and of indoor allergens during the first year of life. Other studies are warranted to assess the interest and efficacy of eviction of inhalant allergens in atopic dermatitis.

Knowledge, attitudes, and behavior of the parents of asthmatic children in Maputo

Asthma is increasing in frequency worldwide. The education of affected children and their parents is fundamental for the management of the disease. The aim of our study was to describe the knowledge, attitudes, and behavior of the parents of asthmatic children. We studied 152 adults accompanying asthmatic children to consultations in the pediatrics department of Maputo Central Hospital (Mozambique). In general, knowledge about asthma was poor: 11% of the adults thought that asthma was contagious and transmitted from person to person, and 4% thought that it was transmitted by contaminated food. More than half the parents thought that the child could not lead a normal life even during the periods between attacks. A large proportion of the parents thought that asthma could be cured by medical treatment in 7% of cases and by alternative treatment in 43% of cases. The precipitating factors were well identified by the adults, but they had an inaccurate perception of the symptoms of an asthma attack. The actions of the various classes of drugs used were poorly understood. Education programs for both the children and their parents should be developed to improve the management of asthmatic children. Surveys of this type facilitate the targeting of such programs.

Risk factors for asthma among children in Maputo (Mozambique)

BACKGROUND

Few studies have looked at risk factors for asthma in African children. We aimed to identify the risk factors associated with childhood asthma in Maputo (Mozambique).

METHODS

This case-control study included 199 age-matched children (100 asthmatic and 99 nonasthmatic) who attended Maputo Central Hospital between January 1999 and July 2000. We collected information concerning their familial history of atopy, birth weight, environment and breast-feeding. Detailed information about morbidity and treatment was obtained for each asthmatic child.

RESULTS

The children were aged between 18 months and 8 years; 60% were male. The asthmatic children were hospitalized more frequently than the nonasthmatic children (P < 0.0001). Most of the asthmatic children lived in the urban area of Maputo [odd ratio (OR) = 6.73, CI = 3.1-14.0, P < 0.0001], had a parental history of asthma (OR = 26.8, CI = 10.8-68.2, P < 0.0001) or rhinitis (OR = 4, CI = 1.2-13.3, P = 0.005), had at least parent who smoked and were weaned earlier than the nonasthmatic children (OR = 2.4, CI = 1.3-4.4, P < 0.001).

CONCLUSION

Childhood asthma was strongly associated with a family history of asthma and rhinitis, the place of residence, having smokers as parents and early weaning from maternal breast milk. These results highlight the need to reassess the management of asthmatic children in Maputo.

Serological characteristics of peanut allergy in children

BACKGROUND

Food challenge is considered an excellent clinical tool for the diagnosis of specific food allergy. However in the case of peanut allergy it may be difficult to perform because of the severity of the reactions. The quantitation of a specific immunoglobulin E (IgE) response to different peanut allergens could also contribute to the improvement of the diagnosis. We characterized the IgE response to a whole peanut protein extract and to Ara h 1 and Ara h 2 in different groups of patients classified according to the severity of their allergic reactions.

METHODS

Specific serum IgE were analyzed in 96 children by enzyme-linked immunosorbent assay tests using a whole protein extract or purified peanut proteins and anti-human IgE monoclonal antibodies labeled with acetylcholinesterase.

RESULTS

A parallel was observed between levels of peanut-specific IgE and the classification in five groups and subgroups of patients upon increasing severity of symptoms, especially within the group of highest severity. Moreover, the highest frequency of positive response and the highest levels of specific IgE were observed with whole peanut protein extract.

CONCLUSION

In a retrospective evaluation of peanut allergy in children, we have shown that quantitation of peanut-specific IgE could be used to avoid a food challenge particularly in the case of severe reactions. When compared to Ara h 1 and Ara h 2, whole peanut protein extract appeared to be the most appropriate allergen to perform the test.

[Streptococcus pneumoniae purulent pleurisy and hemolytic uremic syndrome. A case report]

A 22-month-old infant developed purulent pleurisy caused by Streptococcus pneumoniae and a hemolytic uremic syndrome. The diagnosis was suggested by the classical triad: hemolytic anemia, renal failure and thrombocytemia confirmed by renal biopsy which demonstrated extensive cortical necrosis. Renal involvement was severe, justifying an indication for renal transplantation.

[Latex allergy in children]

The aim of our study was to determine the prevalence of latex allergy and the clinical features of children with latex allergy.

PATIENTS AND METHODS

We prospectively investigated 243 children consulting in our allergy out-patients unit during 1 year. Parents answered a questionnaire, and children underwent skin prick tests with common allergens and latex. Latex-specific serum immunoglobulin E was determined by CAP test in children with latex sensitization. The results were compared in children with and without latex allergy.

RESULTS

The prevalence of latex allergy was 1.3%. A family history of atopy (75%) and a personal history of previous surgery was associated with latex allergy (P < 0.0001). In children with latex allergy, the frequency of sensitization to inhaled and food allergens, atopic dermatitis, rhinitis and conjunctivitis was higher than in children without latex allergy (P < 0.05). Avocado allergy was the food allergy most commonly associated with clinical symptoms. Balloon was the most common latex product causing symptoms (60%).

CONCLUSIONS

Due to its potential severe consequences, latex allergy should be investigated in children who had undergone multiple surgical procedures and in the children with pollen-food allergy syndrome. Avoidance of latex is an important preventive measure.

[Food allergy and asthma in children]

The links between food allergy and asthma are becoming more clear. The association of food allergy and asthma in the same child is unusual (less than 10% in atopic subjects). This association is however a sign of gravity leading to more severe manifestations of food allergy in asthmatic children. Compared with the non-asthmatic child, the asthmatic child has a 14-fold higher risk of developing a severe allergic reaction to the ingestion of food. The most commonly cited foods are fruits with a rind, cow's milk and, of course, nuts. Epidemiological data established from methodologically sound studies should enable a definition of the current allergic environment. Formal diagnosis is established with standardized tests. Treatment is oriented towards prevention associating a restricted diet, asthma control, patient education, and prescription of an emergency first aid kit with epinephrine. Supplementary inquiries are needed to determine the outcome in children with food allergy and respiratory symptoms.