The Burden of the Atopic March: Real-World Data on Pediatric AD and Allergic Comorbidities in Japan

Atopic dermatitis (AD) often represents the first step in the “atopic march” in pediatric patients, preceding the development of allergic rhinitis, asthma, and food allergy.¹ Although these allergic comorbidities (ACMs) are well recognized clinically, large-scale real-world data describing how they influence treatment patterns and healthcare utilization in young children remain limited. A recent Japanese nationwide claims-based study has provided important insights into the clinical and economic burden of pediatric AD in routine practice.²

Study Design

Investigators conducted a retrospective observational analysis of children aged 0 to 6 years diagnosed with AD between January 2018 and September 2023. Information was extracted from the JMDC database, which captures longitudinal healthcare data from approximately 19 million individuals in Japan. A total of 244,316 children met the inclusion criteria, with a mean age of 3.1 years. Patients were stratified into those with AD alone and those with AD plus at least 1 ACM (asthma, allergic rhinitis, or food allergy).

Approximately 82% of children with AD had at least 1 ACM, reinforcing the close biological link between cutaneous and systemic allergic disease early in life. Allergic rhinitis was the most common comorbidity, followed by asthma and food allergy. This distribution is consistent with the natural history of the atopic march.

Treatment Patterns

Treatment patterns differed substantially between children with AD alone and those with comorbid allergic disease. Topical corticosteroids remained the cornerstone of therapy in both groups, but were used more frequently and at higher potencies in children with ACMs. Overall, 94.0% of children with AD and ACMs received topical corticosteroids, compared with 85.5% of those with AD alone. Importantly, the use of potent and very potent topical corticosteroids increased progressively with the number of comorbidities, suggesting that children with multisystem allergic disease experience more severe or refractory eczema requiring stronger anti-inflammatory control.

Nonsteroidal topical agents, including calcineurin inhibitors and topical JAK inhibitors, were used in a minority of patients, reflecting limited penetration of newer therapies into very young pediatric populations during the study period. Systemic treatments showed even more pronounced differences between groups. Antihistamines were prescribed to nearly all children with ACMs (95.5%) compared with just over half of those with AD alone (56.1%). Systemic corticosteroid exposure was also markedly higher in children with ACMs (31.5% vs. 4.8%), particularly in those with asthma, likely reflecting their use during respiratory exacerbations.

Economic Impact

Health care resource utilization mirrored these treatment differences. Children with AD and ACMs had substantially more outpatient visits, averaging 11.1 visits per year compared with 6.5 visits among those with AD alone, indicating a greater need for ongoing medical supervision. Hospitalization rates were similar between groups, but children with AD alone had longer hospital stays, a finding the authors suggest may reflect heterogeneous reasons for admission, including educational hospitalizations common in Japan for intensive eczema management.

The economic impact of allergic comorbidity was pronounced. Median annual healthcare costs were approximately 40% higher in children with AD and ACMs (139,391 Yen) than in those with AD alone (98,646 Yen). Costs rose in a stepwise fashion with each additional comorbidity, reaching a median of 193,671 Yen per year in children with 3 ACMs. Notably, 84.7% of children with 3 comorbid allergic diseases exceeded the national average annual pediatric health care cost.

Clinical Implications

These findings have important implications for dermatologists, according to the study authors:

• They reinforce that pediatric AD is rarely an isolated skin condition, as most patients present within a broader allergic diathesis that drives higher treatment intensity and health care utilization.
• The progressive increase in potent topical corticosteroid and systemic steroid use with increasing comorbidity highlights the need for more effective, steroid-sparing strategies that address shared inflammatory pathways across the atopic spectrum.
• The escalating costs associated with multiple ACMs emphasize the potential long-term economic benefits of earlier, more comprehensive disease control.

References

1. Hill DA, Spergel JM. The atopic march: Critical evidence and clinical relevance. Ann Allergy Asthma Immunol. 2018;120(2):131-137. doi:10.1016/j.anai.2017.10.037

2. Futamura M, Kang Y, Singh A, et al. Treatment Patterns and Healthcare Utilization on Pediatric Atopic Dermatitis With Allergic Comorbidities: A Japanese Claims-Based Study. J Dermatol. Published online January 8, 2026. doi:10.1111/1346-8138.70102