Anemia a Risk in Children With Atopic Disease: Study

By Megan Brooks

December 02, 2015

NEW YORK (Reuters Health) - Atopic disease raises the risk of anemia in children and adolescents, according to data from two large population-based surveys.

Dr. Johnathan Silverberg and colleagues from Northwestern University Feinberg School of Medicine in Chicago analyzed data on 207,000 children and adolescents in the US National Health Interview Survey (NHIS) and about 30,600 from the National Health and Nutrition Examination Survey (NHANES).

"We analyzed data from 17 rounds of the National Health Interview Survey and six rounds of the National Health and Nutrition Examination Survey," Dr. Silverberg told Reuters Health by email.

In the NHIS, a history of caregiver-reported eczema, asthma, hay fever, and food allergy was associated with increased likelihood of anemia, with adjusted odds ratios of 1.83, 1.31, 1.57, and 2.08, respectively (p<0.001 for all), the researchers reported November 30 in JAMA Pediatrics.

The odds of anemia increased with the number of atopic disorders. Having a single atopic disorder modestly increased the risk of anemia (aOR 1.84) while having all four "demonstrably" increased the risk (aOR 7.87).

In the NHANES, childhood asthma (aOR 1.33) and eczema (aOR 1.93) were associated with higher likelihood of anemia, particularly microcytic anemia (asthma: aOR 1.61; eczema: aOR 2.03) as defined by laboratory assay test results, while hay fever was not (aOR 0.85).

The researchers say the link between atopic disease and microcytic anemia might be related to anemia of chronic disease (ACD). "This possibility may explain why a higher number of atopic disorders was associated with increasing odds of anemia in the NHIS," they note.

The exact mechanism for the observed link between atopic disease and anemia is unknown, but is likely multifactorial, the researchers say. "Atopic disease is associated with chronic inflammation, food allergen avoidance, and use of systemic immunosuppressant medications. All these factors have been shown to be associated with anemia," they point out.

"Regardless of the underlying mechanisms, awareness of the association between atopic disease and anemia is important," they note.

"There are several important points for consideration by parents and healthcare providers," Dr. Silverberg told Reuters Health.

"Children with atopic diseases have higher rates of fatigue, which are usually attributed to chronic sleep disturbances. However, unrecognized anemia may contribute to fatigue in atopic children and should be considered in those with excessive or unremitting fatigue," he noted.

"Patients with eczema and asthma often try strict avoidance diets devoid of milk and egg products. Such avoidance diets can be harmful and result in malnutrition and iron deficiency anemia in extreme cases. Moreover, such avoidance diets are largely not helpful for the clearance of eczema, asthma and hay fever," Dr. Silverberg said.

He notes that he commonly encounters patients in clinical practice with malnutrition from inappropriate avoidance diets. He recommends that atopic patients with suspected food allergy be properly evaluated for food allergy before starting any avoidance diets.

Given the cross-sectional nature of the study, conclusions about the directionality of the observed associations aren't possible, the researchers note in their paper. Given this and other limitations, "future studies with even larger cohorts and/or case-control studies and expanded diagnostic testing are needed to verify these findings," they conclude.

The study had no commercial funding and the authors have no relevant disclosures.


JAMA Pediatr 2015.


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