Frequent oil baths and skin barrier during infancy in the PreventADALL study.

BACKGROUND: In the general population randomized controlled trial PreventADALL, frequent emollient bath additives from 2 weeks of age did not prevent atopic dermatitis, while the effect on skin barrier function throughout infancy is not established. OBJECTIVES: The primary aim of this exploratory substudy was to assess the effect of mineral-based oil baths on transepidermal water loss (TEWL) and dry skin through infancy, and secondarily to explore if filaggrin (FLG) mutations modified the effect. METHODS: Overall, 2153 infants were included and randomized to either the 'Skin intervention' (SI) group (n = 995) (oil bath 4 times weekly from 2 weeks through 8 months) or 'No skin intervention' (NSI) group (n = 1158), with TEWL measurements at 3, 6 and/or 12 months of age. Information on FLG mutation status was available for 1683 of these infants. Effects of the skin intervention on TEWL and dry skin through infancy were assessed by mixed-effects regression modelling. Background characteristics and protocol adherence were collected from electronic questionnaires, birth records and weekly diaries. RESULTS: The TEWL (95% confidence interval) was on average 0.42 g m-2 h-1 (0.13-0.70, P = 0.004) higher in the SI group compared with the NSI group through the first year of life, with significantly higher levels at 3 months [8.6 (8.3-9.0) vs. 7.6 (7.3-7.9)], but similar at 6 and 12 months. Dry skin was observed significantly more often in the NSI group compared with the SI group at 3 months (59% vs. 51%) and at 6 months of age (63% vs. 53%), while at 12 months of age, the difference was no longer significant. At 3 months, the TEWL of FLG mutation carriers was similar to the TEWL in the SI group. No interaction between SI and FLG mutation was found in the first year of life. CONCLUSIONS: Infants given frequent oil baths from 2 weeks of age had reduced skin barrier function through infancy compared with controls, largely attributed to higher TEWL at 3 months of age, while the skin at 3 and 6 months appeared less dry in infants subjected to the skin intervention.

Atopic dermatitis (AD) affects approximately 20% of children in industrialized countries. AD causes dry, itchy skin and can increase the chance of infections. This study was a substudy of the large Scandinavian PreventADALL trial, including 2394 infants, recruited from the general population between 2014 and 2016. Children in this trial were allocated randomly to receive either a skin intervention, food intervention, combined intervention, or no intervention. Children were examined at 3, 6 and 12 months of age. The examinations involved an investigation of the skin, to evaluate dry skin and skin barrier function by transepidermal water loss (TEWL) in the outer layers of the skin (higher TEWL suggests decreased skin barrier function). The skin intervention consisted of oil baths at least 4 times per week from 2 weeks of age through 8 months of age, and have previously not been shown to prevent AD by 1 and 3 years of age. We aimed to investigate whether frequent oil baths had any effect on TEWL and dry skin. We found that the skin intervention increased TEWL in the first year of life, especially at 3 months of age. Dry skin was less common in the skin intervention groups compared with the groups with no skin intervention. Infants with mutations in the gene coding for a skin barrier protein, called filaggrin, were associated with increased TEWL; however, in the skin intervention group, TEWL was similar among the infants with or without filaggrin mutations. Our findings suggest that oil baths several times per week from early infancy transiently decreases skin barrier function.

Impaired skin barrier and allergic sensitization in early infancy.

BACKGROUND: Factors predicting allergic sensitization in the first 6 months of life are poorly understood. We aimed to determine whether eczema, dry skin, and high transepidermal water loss (TEWL) at 3 months were associated with allergic sensitization at 6 months of age and, secondarily, to establish whether these characteristics predicted sensitization from 3 to 6 months of age. METHODS: At 3 months of age, 1,994 infants from the population-based PreventADALL birth cohort in Norway and Sweden were assessed for eczema and dry skin on the cheeks and/or extensors; impaired skin barrier function, defined as TEWL in the upper quartile (>9.4 g/m2 /h), and allergen-specific IgE levels <0.1 kUA /L, available in 830. At 6 months, we assessed allergic sensitization to any food (egg, cow's milk, peanut, wheat, soy) or inhalant (birch, timothy grass, dog, and cat) allergen by a skin prick test wheal diameter ≥2 mm larger than negative control. RESULTS: Any sensitization was found in 198 of the 1,994 infants (9.9%), the majority to food allergens (n = 177, 8.9%). Eczema, dry skin, and high TEWL at 3 months increased the risk of sensitization at 6 months; adjusted odds ratios 4.20 (95% CI 2.93-6.04), 2.09 (95% CI 1.51-2.90) and 3.67 (95% CI 2.58-5.22), respectively. Eczema predicted sensitization with 55.6% sensitivity and 68.1% specificity; dry skin with 65.3% sensitivity and 57.3% specificity; and high TEWL with 61.7% sensitivity and 78.1% specificity. CONCLUSION: Eczema, dry skin, and high TEWL at 3 months predicted allergic sensitization at 6 months of age.

Evaluation of Skin Prick Test Reading Time at 10 versus 15 min in Young Infants.

INTRODUCTION: The optimal time point for reading the mean wheal diameter (MWD) of a skin prick test (SPT) in infants is not established. We aimed to assess if either of two reading time points of the SPT, 10 or 15 min, was superior to detect allergic sensitization (AS) in 6-month-old infants. METHODS: In 1,431 6-month-old infants from the population-based Preventing Atopic Dermatitis and ALLergies in children (PreventADALL) mother-child cohort, the SPT was performed with standard solutions for egg, cow's milk, peanut, wheat, soy, birch, timothy, dog, and cat. The MWD was measured after 10 and 15 min. AS was defined as a positive SPT with MWD ≥2 mm larger than the negative control. RESULTS: Overall, 149 (10.4%) infants were sensitized to at least one allergen at 10 and/or 15 min, while 138 (9.6%) had a positive SPT at 10 min and 141 (9.9%) at 15 min. A total of 12,873 allergen pricks were performed with 212 (1.6%) being positive at any time point, 194 (1.5%) positive at 10 min, and 196 (1.5%) positive at 15 min. The mean (95% CI) histamine MWD of 3.8 (3.8, 3.9) mm at 10 min was significantly larger than the 3.6 (3.6, 3.7) mm at 15 min. DISCUSSION/CONCLUSIONS: Reading the SPT after both 10 and 15 min increased the number of 6-month-old infants with documented AS compared to reading after one time point only. As neither 10 nor 15 min reading time was superior to the other in detecting AS, our results indicate that readings at both time points should be considered. However, the histamine MWD was significantly larger at 10 min compared to 15 min. Reappraisal of SPT reading in infancy may be warranted.