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The Importance of Allergen Avoidance in High Risk Infants and Sensitized Patients: A Meta-analysis Study.

Huiyan W, Yuhe G, Juan W, Junyan Z, Shan W, Xiaojun Z, Ailin T - Allergy Asthma Immunol Res (2014)

Bottom Line: Meta-analysis demonstrated that allergen avoidance for newborns did not reduce the subsequent incidence of allergic diseases (eczema, P=0.21; rhinitis, P=0.3; cough, P=0.1) but significantly reduced the incidence of asthma and wheezing in high-risk infants (asthma, P=0.03; wheeze, P=0.0004).Allergen avoidance may not always be successful in preventing allergic symptoms.However, rigorous methodological studies are required to confirm this hypothesis.

View Article: PubMed Central - PubMed

Affiliation: Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, the State Key Laboratory of Respiratory Disease, the Second Affiliated Hospital of Guangzhou Medical University, Guangdong 510260, China.

ABSTRACT

Purpose: At this time, there is uncertainty regarding whether allergen avoidance is the most appropriate strategy for managing or preventing allergies. The purpose of this study was to evaluate the effectiveness of allergen avoidance in the prevention of allergic symptoms in previously sensitized patients and newborns that have the potential to develop allergies.

Methods: We performed online searches of articles published from January 1980 to December 2012 in PubMed and The Cochrane Central Register of Controlled Trials, and selected articles involving randomized controlled trials (RCTs) and allergen avoidance. The parameters used to determine allergenic potential in newborns included the risk ratio (RR) of eczema, asthma, rhinitis, wheeze, and cough. The methods employed to evaluate previously sensitized patients were the standardized mean difference (SMD) of forced expiratory volume in 1 second (FEV1) and peak expiratory flow rate (PEFR). Data quality was assessed using the Jadad scale.

Results: A total of 14 RCTs were identified. Meta-analysis demonstrated that allergen avoidance for newborns did not reduce the subsequent incidence of allergic diseases (eczema, P=0.21; rhinitis, P=0.3; cough, P=0.1) but significantly reduced the incidence of asthma and wheezing in high-risk infants (asthma, P=0.03; wheeze, P=0.0004). However, previously sensitized patients who reduced their exposure to known allergens did not show improvement in their lung functions (FEV1, P=0.3; PEFR morning, P=0.53; PEFR evening, P=0.2; PEFR, P=0.29).

Conclusions: Allergen avoidance may not always be successful in preventing allergic symptoms. However, rigorous methodological studies are required to confirm this hypothesis.

No MeSH data available.


Related in: MedlinePlus

Forest plot showing the risk ratio for the incidence of asthma comparing allergen avoidance to the control in newborns with the potential to develop allergies. There was a significant difference between the experimental and control groups (P=0.03), indicating the effectiveness of allergen avoidance in high-risk infants.
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Figure 5: Forest plot showing the risk ratio for the incidence of asthma comparing allergen avoidance to the control in newborns with the potential to develop allergies. There was a significant difference between the experimental and control groups (P=0.03), indicating the effectiveness of allergen avoidance in high-risk infants.

Mentions: The fixed-effect models were also utilized for the analysis of eczema (χ2=6.92, df=6, P=0.33) (Fig. 2), rhinitis (χ2=4.66, df=5, P=0.46) (Fig. 3), and cough (χ2=2.27, df=5, P=0.81) (Fig. 4). Overall analysis of these 3 symptoms demonstrated that allergen avoidance, including reduction of exposure to environment allergens and early dietary antigen avoidance, did not reduce the risk of infants for the development of eczema (RR=0.89, 95% CI=0.74-1.07; Z=1.24, P=0.21) (Fig. 2), rhinitis (RR=0.91, 95% CI=0.77-1.09; Z=1.03, P=0.30) (Fig. 3), or cough (RR=0.84, 95% CI=0.68-1.04; Z=1.64, P=0.10) (Fig. 4). Similarly, no obvious heterogeneity was observed in the analysis of asthma (χ2=10.20, df=6, P=0.12) (Fig. 5) and wheezing (χ2=4.71, df=5, P=0.45) (Fig. 6), supporting the use of a fixed-effects model. The result of the overall analysis of asthma and wheezing was opposite to that of eczema, rhinitis, and cough, and demonstrated that allergen avoidance significantly reduced the incidence of asthma and wheezing in high-risk infants (asthma RR=0.8, 95% CI=0.65-0.98, Z=2.15, P=0.03; wheezing RR=0.73, 95% CI=0.61-0.87, Z=3.51, P=0.0004).


The Importance of Allergen Avoidance in High Risk Infants and Sensitized Patients: A Meta-analysis Study.

Huiyan W, Yuhe G, Juan W, Junyan Z, Shan W, Xiaojun Z, Ailin T - Allergy Asthma Immunol Res (2014)

Forest plot showing the risk ratio for the incidence of asthma comparing allergen avoidance to the control in newborns with the potential to develop allergies. There was a significant difference between the experimental and control groups (P=0.03), indicating the effectiveness of allergen avoidance in high-risk infants.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4214973&req=5

Figure 5: Forest plot showing the risk ratio for the incidence of asthma comparing allergen avoidance to the control in newborns with the potential to develop allergies. There was a significant difference between the experimental and control groups (P=0.03), indicating the effectiveness of allergen avoidance in high-risk infants.
Mentions: The fixed-effect models were also utilized for the analysis of eczema (χ2=6.92, df=6, P=0.33) (Fig. 2), rhinitis (χ2=4.66, df=5, P=0.46) (Fig. 3), and cough (χ2=2.27, df=5, P=0.81) (Fig. 4). Overall analysis of these 3 symptoms demonstrated that allergen avoidance, including reduction of exposure to environment allergens and early dietary antigen avoidance, did not reduce the risk of infants for the development of eczema (RR=0.89, 95% CI=0.74-1.07; Z=1.24, P=0.21) (Fig. 2), rhinitis (RR=0.91, 95% CI=0.77-1.09; Z=1.03, P=0.30) (Fig. 3), or cough (RR=0.84, 95% CI=0.68-1.04; Z=1.64, P=0.10) (Fig. 4). Similarly, no obvious heterogeneity was observed in the analysis of asthma (χ2=10.20, df=6, P=0.12) (Fig. 5) and wheezing (χ2=4.71, df=5, P=0.45) (Fig. 6), supporting the use of a fixed-effects model. The result of the overall analysis of asthma and wheezing was opposite to that of eczema, rhinitis, and cough, and demonstrated that allergen avoidance significantly reduced the incidence of asthma and wheezing in high-risk infants (asthma RR=0.8, 95% CI=0.65-0.98, Z=2.15, P=0.03; wheezing RR=0.73, 95% CI=0.61-0.87, Z=3.51, P=0.0004).

Bottom Line: Meta-analysis demonstrated that allergen avoidance for newborns did not reduce the subsequent incidence of allergic diseases (eczema, P=0.21; rhinitis, P=0.3; cough, P=0.1) but significantly reduced the incidence of asthma and wheezing in high-risk infants (asthma, P=0.03; wheeze, P=0.0004).Allergen avoidance may not always be successful in preventing allergic symptoms.However, rigorous methodological studies are required to confirm this hypothesis.

View Article: PubMed Central - PubMed

Affiliation: Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, the State Key Laboratory of Respiratory Disease, the Second Affiliated Hospital of Guangzhou Medical University, Guangdong 510260, China.

ABSTRACT

Purpose: At this time, there is uncertainty regarding whether allergen avoidance is the most appropriate strategy for managing or preventing allergies. The purpose of this study was to evaluate the effectiveness of allergen avoidance in the prevention of allergic symptoms in previously sensitized patients and newborns that have the potential to develop allergies.

Methods: We performed online searches of articles published from January 1980 to December 2012 in PubMed and The Cochrane Central Register of Controlled Trials, and selected articles involving randomized controlled trials (RCTs) and allergen avoidance. The parameters used to determine allergenic potential in newborns included the risk ratio (RR) of eczema, asthma, rhinitis, wheeze, and cough. The methods employed to evaluate previously sensitized patients were the standardized mean difference (SMD) of forced expiratory volume in 1 second (FEV1) and peak expiratory flow rate (PEFR). Data quality was assessed using the Jadad scale.

Results: A total of 14 RCTs were identified. Meta-analysis demonstrated that allergen avoidance for newborns did not reduce the subsequent incidence of allergic diseases (eczema, P=0.21; rhinitis, P=0.3; cough, P=0.1) but significantly reduced the incidence of asthma and wheezing in high-risk infants (asthma, P=0.03; wheeze, P=0.0004). However, previously sensitized patients who reduced their exposure to known allergens did not show improvement in their lung functions (FEV1, P=0.3; PEFR morning, P=0.53; PEFR evening, P=0.2; PEFR, P=0.29).

Conclusions: Allergen avoidance may not always be successful in preventing allergic symptoms. However, rigorous methodological studies are required to confirm this hypothesis.

No MeSH data available.


Related in: MedlinePlus