Infants with atopic dermatitis (AD) are at an increased risk for developing a sequence of allergic conditions, a phenomenon known as the atopic march, according to a new study. Severe disease, male sex, family history of allergies, and prenatal factors were found to significantly raise the likelihood of progression to conditions such as asthma, allergic rhinitis, and food allergies.
The atopic march describes the pattern in which individuals, typically starting with AD in infancy, later develop other allergic conditions, forming a cascade of allergic disorders. While this sequence is well-documented, the exact timing and factors that contribute to its progression remain areas of ongoing research.
Dr. Una E. Choi, of the University of Maryland School of Medicine, and her team sought to investigate the early factors that contribute to this progression. “AD is often diagnosed before asthma, allergic rhinitis, and food allergy develop, forming a classic atopic march,” Dr. Choi said. However, the temporal relationship between early-onset AD and the development of the full atopic march had not been fully understood until now.
The study, which utilized the MarketScan Research Database spanning from 2010 to 2018, included a cohort of 27,228 infants diagnosed with AD before age 1 and 55,174 control infants with no history of AD. Of the infants with AD, 60.3% were male, and 51% of the controls were male.
The findings indicated that infants with AD were significantly more likely to develop additional allergic conditions compared to those without AD. Specifically, 19.2% of AD patients developed asthma, compared to just 8.7% of controls. Similarly, 28.3% of AD patients developed allergic rhinitis, compared to 12.6% in the control group. Furthermore, 16% of AD patients developed food allergies, compared to only 2.3% of controls. The combination of all three conditions, known as the atopic triad, occurred in 10.7% of AD patients, a stark contrast to just 0.7% in controls (P < 0.001 for all comparisons).
The study also tracked the timing of these developments. Among those diagnosed with AD, 20.1% developed allergic rhinitis as their second atopic condition, with an average time of 498 days following their AD diagnosis. Asthma developed in 12.4% of cases after a mean of 408 days, and 11.9% developed food allergies after an average of 269 days.
Several factors were identified as contributing to an increased risk of progression to the atopic triad. Male infants had a higher risk (hazard ratio [HR] = 1.66), as did those with severe AD (HR = 3.16) or a family history of atopic conditions (HR > 3.4; P < 0.001). Additionally, infants born via cesarean section and those whose mothers used antibiotics during pregnancy were also at heightened risk for developing the full atopic march.
Despite the study’s valuable insights, Dr. Choi and her team acknowledged a limitation in the study design, noting that the use of healthcare claims data may not fully capture all relevant clinical details.
“Early-onset AD is associated with higher rates of developing atopic march conditions compared to controls,” Dr. Choi emphasized. “Our findings suggest that early attention to risk factors and screening for atopic march is critical for infants with AD.”
Related topics
