Children with a history of atopic disease (AD) are at a significantly higher risk for an anemia diagnosis than are children without AD, according to an analysis of two large U.S. population-based studies.
In addition, the risk of anemia increased with the number of caregiver-reported atopic disorders, reported the investigators, Dr. Jonathan I. Silverberg and his associates in the department of dermatology, Northwestern University, Chicago. A current diagnosis of eczema or asthma was associated with a significantly increased risk of anemia, particularly microcytic anemia, in the study, published online on Nov. 30 in JAMA Pediatrics (doi: 10.1001/jamapediatrics.2015.3065).
Dr. Jonathan I. Silverberg
The authors evaluated data from the U.S. National Health Interview Survey (NHIS) on about 207,000 children and adolescents collected between 1997 and 2013, and from the National Health and Nutrition Examination Survey (NHANES) on nearly 31,000 children and adolescents between 1999 and 2012.
Data from the NHIS cohort found a significantly elevated anemia risk among children with a caregiver-reported history of hay fever, eczema, asthma, and food allergy (P less than .001 for all 4 disorders). After adjustments for age, sex, ethnicity and socioeconomic factors, the anemia risk for a child with any single atopic disorder was modestly elevated (adjusted odds ratio, 1.84; 95% confidence interval, 1.60-2.11; P less than .001). The adjusted risk among those with all four disorders was markedly elevated (adjusted OR, 7.87; 95% CI, 5.17-12.00; P less than .001).
In the NHANES cohort, the investigators found a current asthma or eczema diagnosis associated with anemia, as defined by laboratory assessment (adjusted OR, 1.33; 95% CI, 1.04-1.70; P = .02 for asthma; and an adjusted OR 1.93; 95% CI, 1.04-3.59; P = .04 for eczema).
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In the NHANES cohort, asthma was associated with an increased risk for microcytic anemia (adjusted OR, 1.61; 95% CI 1.09-2.38 P = .02). In the 2005-2006 NHANES cohort, a history of eczema was associated with an increased risk of microcytic anemia (adjusted OR, 2.03; 95% CI, 1.20-3.46; P = .009). But no significant associations for hay fever and any type of anemia were noted.
While the reasons for the observed association between atopic disease and anemia remain unknown and are probably multifactorial, physicians “should be aware that fatigue may be related to unrecognized anemia and not merely sleep loss owing to atopic dermatitis or airway disease,” the investigators wrote. Moreover, they noted, restricted diets to treat atopic disorders could play a role. “This finding underscores the importance of properly evaluating and ruling out suspected food allergy in children rather than placing them on empirical avoidance diets that might contribute to anemia,” they said.
The study was funded by the Agency for Healthcare Research and Quality and the Dermatology Foundation. Dr. Silverberg and his coauthors, Kerry E. Drury and Matt Schaeffer, declared no conflicts of interest.