Atopic Dermatitis in Infancy

Challenges in the diagnosis of atopic dermatitis (AD) in infants were outlined in study data published in the British Journal of Dermatology. In a cohort study of infants with eczema, approximately one-third fulfilled diagnostic criteria for AD. Earlier presentation of eczema and persistent eczema were associated with higher likelihood of later AD diagnosis.

Although eczema is common in infants, the percentage of infants with eczema and AD is unknown. To better elucidate the incidence of eczema and AD in infants, investigators conducted an analysis within an existing cohort study of infants born in Norway from 2014 to 2016. Clinical follow-up was performed at 3, 6, and 12 months of age. Follow-up visits included a skin assessment by an experienced dermatologist. The primary outcome was observed eczema at follow-up. The secondary outcome was the percentage of infants with eczema fulfilling either the UK Working Party (UKWP) or the Hanifin and Rajka (H&R) criteria for clinical AD at 12 months. Logistic regression models were used to examine the relationship between eczema and AD in infancy. Models were adjusted for infant sex and parental atopic disease.

The present large, prospective, population-based cohort enrolled 1834 infants, of whom 52.8% were boys. Overall, 34.2% of infants presented with eczema at any study visit; 12.1% had eczema at 2 visits; and 4.3% had eczema at all visits. The prevalence of eczema was 13.1% at the 3-month visit, 19.6% at the 6-month visit, and 17.9% at the 12-month visit. At 12 months of age, 33.7% of infants fulfilled diagnostic criteria for AD on at least 1 of the 2 validated tools. Among infants with eczema at 3, 6, and 12 months, 47%, 22%, and 30% received a clinical diagnosis of AD at 12 months, respectively. Among infants with eczema at all 3 study visits, 87.1% received a diagnosis of AD at 12 months. In regression models, infants with eczema at all study visits were significantly more likely than infants with eczema at 1 study visit to fulfill AD criteria at 12 months (odds ratio [OR], 23.1; 95% confidence interval [CI], 12.3-43.6). The same trend was observed for infants with eczema at 2 of 3 study visits (OR, 6.5; 95% CI, 4.3-9.9).

The odds of AD were substantially lower for infants with eczema first observed at 6 months (OR, 0.33; 95% CI, 0.22-0.48) or 12 months (OR, 0.49; 95% CI, 0.32-0.74) compared with infants with eczema first observed at 3 months. Of infants with eczema at 12 months, 47.4% fulfilled criteria for AD: 8% fulfilled UKWP criteria only, 20% fulfilled H&R criteria only, and 72% fulfilled both UKWP and H&R criteria. A significant percentage,34.1%, of infants fulfilling H&R criteria did not meet the itch criterion, suggesting that itch may not be always have diagnostic utility in infants.

Eczema was observed in approximately one-third of infants. Among these infants, one-third were later diagnosed with AD per the UKWP and/or H&R criteria. Infants with eczema at 3 months of age and/or eczema observed at 3 separate study visits were most likely to meet AD criteria.

Study limitations include the complexity and difficulty of assessment for some of the AD diagnostic criteria; several minor criteria for AD are not often present in infancy. Further, the provision of AD treatment of study visits may have alleviated symptoms and, as such, led to an underestimation of AD prevalence in the cohort.

“[T]his study documents the limitations of the UKWP and H&R criteria in diagnosing AD in the first year of life,” investigators wrote. “Repeated clinical observations and applying both sets of criteria may be the most appropriate way in which to diagnose AD in infants and the most useful in clinical research.”

Disclosure: Two study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures. 

Reference

Endre KMA, Landrø L, LeBlanc M, et al. Diagnosing atopic dermatitis in infancy using established diagnostic criteria: a cohort study. Br J Dermatol. Published online January 28, 2021. doi: 10.1111/bjd.19831