Early identification of high-risk infants for atopic dermatitis (AD) in the pre-disease stage can be crucial as it allows more well-timed and effective targeted intervention for AD prevention.¹ During the 2024 AAAAI Annual Meeting, Dr. Elizabeth Tham from the National University of Singapore, presented the results of a sub-study within the Singapore Preconception Study of Long-Term Maternal and Child Outcomes (S-PRESTO), which aimed to identify signatures of early skin microbiome, natural moisturizing factors (NMFs) and anti-microbial peptides (AMPs) that can predict infantile AD at 6 and 18 months of life.¹

In this sub-cohort from the S-PRESTO study (n=119), skin tape strips were collected from infants at 1 week, 3 months, 6 months and 18 months, and analyzed for whole metagenomics sequencing, and AMP and NMF profiling.¹ Children were assessed for AD by trained physicians at 6 and 18 months.¹ A total of 60 infants were diagnosed with AD at 18 months while 59 infants served as healthy controls.¹ In terms of skin microbial diversity, both AD and healthy infants experienced an increase in Shannon diversity over time, yet no significant differences were observed between the groups.¹ However, an increased abundance of Pseudomonas stutzeri at week 1 was found to be associated with elevated AD risk at 18 months, whereas increased abundance Corynebacterium aurimucosum, Corynebacterium diptheriae and Rothia dentocariosa was associated with reduced AD risk at 18 months.¹

For NMFs, higher concentrations of L-Histidine, L-Argine and Urocanic acid-trans before 6 months of age were found to be associated with AD by month 18.¹ On the other hand, higher concentrations of Pyrrolidone Carboxylic Acid (PCA) and Urocanic acid-cis before 6 months of age were associated with lower odds of AD at 18 months.¹ Furthermore, AMP concentrations in early life also differed between the groups, with elevated levels of DEFA1, BD1, BD2, S100A7 and S100A9 and reduced levels of TRFL and BD3 before 3 months of age found to be associated with increased odds of AD at month 18.¹

The association between the skin microbiome and metabolites with different AD phenotypes was further analyzed in this study, which included early onset transient AD (AD at month 6 but not month 18), early onset persistent AD (AD at month 6 and month 18), and late-onset AD (no AD at month 6 but AD present at month 18).¹ Increased abundance of P. stutzeri at week 1 was associated with higher odds of early onset persistent AD but AD odds were lower in infants with increased Corynebacterium jeikenium abundance at 3 months.¹ Higher concentrations of L-Histidine, L-Arginine, PCA, and Urocanic acid-trans at week 1 were associated with late-onset AD.¹ Lastly, higher BD1, DEFA1, CAMP and S100A7 concentrations at week 1 were associated with early onset persistent AD, while higher BD1, BD2, DEFA1, CAMP and S100A9 at week 1 were associated with early onset transient AD.¹

In summary, the findings of the study established that certain skin microbiota, NMF and AMP signatures in early life can be potential predictive markers for AD at 18 months of age.¹ Implementing the assessments of these predictors could assist in identifying high-risk infants who may benefit from targeted strategies in early life for AD prevention.¹