麻豆传媒

SAN DIEGO -- The scientific program of the American Academy of Dermatology annual meeting included dozens of poster presentations, spread over 4 days. Several of the posters are summarized below.

Stopping Atopic Dermatitis Before It Starts

An aggressive topical-emollient regimen initiated as part of neonatal care reduced the incidence of atopic dermatitis (AD) in high-risk infants by half at 6 months as compared with infants who did not receive the skin care, French researchers reported.

The study involved 120 infants at high risk of AD because of family history. They were randomized to a prevention strategy or to standard care (application of a topical emollient only for dry skin and followed for 6 months. An additional 60 normal-risk neonates served as an additional control.

The prevention strategy consisted of twice-daily application of an emollient, twice-weekly treatment with a cleansing cream, and twice-weekly bath-oil treatment. Outcomes of interest were first AD flare, levels of natural moisturizing factors (NMFs) and ceramides, and colonization with Staphylococcus aureus or S. epidermidis.

At 6 months, five (8.3%) children in the prevention group and 11 (18.3%) in the control group had clinical signs associated with AD (RR 0.45, 95% CI 0.17-1.23, P=0.11). NMFs and ceramides were lower at every time point for the two at-risk groups versus the normal-risk group during the first 100 days, but the prevention strategy returned the levels to near normal by 6 months. Evidence of Staphylococcal colonization appeared in 45 children, and the rate did not differ between the high-risk prevention and control groups, Gaëlle Bellemère, of Laboratoires Expanscience in Epernon, France, and co-investigators reported.

High Placebo Response Caveat for Trial Design

Placebo response rates as high as 50% in studies of systemic therapy for AD should serve as a strong cautionary factor for future trial design, authors of a systematic review concluded.

In the review -- which encompassed data for 46 randomized, controlled trials -- the mean placebo response ranged between 19% and 28%, depending on the outcome measure. The highest placebo response rate (28.2%) was observed with the Eczema Area and Severity Index (EASI) as the primary outcome measure, and the lowest rate was associated with use of the Numerical Rating Scale- or Visual Analog Scale-Itch.

In trials allowing concomitant use of topical therapy, the placebo response averaged 52.50% when the EASI was used. When topical therapy was not allowed, mean placebo response rates ranged from 10.20% when the itch indices were used to 29.30% when the Scoring Atopic Dermatitis (SCORAD) index was used. The placebo response declined to 22.10% for the EASI when topicals were not allowed (P=0.025).

Factors that had significant associations with high placebo responses were a male predominance in the study population (P=0.008) and trials that included children (P=0.02), followed by lower baseline AD severity (P=0.06), lower baseline itch score (P=0.10), and lower baseline EASI score (P=0.17), reported Harrison H. Lee of Northwestern University in Chicago, and co-investigators.

Skin Cancer Prevention: Words Matter

Internet-based skin cancer prevention campaigns might increase their effectiveness by emphasizing the words "sunscreen" and "sunburn" over "skin cancer" and "melanoma," a study of Google search statistics suggested.

Noting that the search terms sunscreen, sunburn, melanoma, and skin cancer are correlated, Zachary H. Hopkins and Aaron M. Secrest, MD, PhD, of the University of Utah in Salt Lake City, hypothesized that the search terms also would correlate with melanoma incidence and mortality. To test the hypothesis, they queried Google Trends for searches involving the four terms during 2004-2017 and compared the results with national data on melanoma mortality and incidence for the same time period.

The analysis showed strong correlations between the terms and melanoma incidence and mortality. However, searches for sunscreen/sunburn had the strongest correlation (r=0.95), followed by sunscreen/skin cancer (r=0.64) and sunscreen/melanoma (r=0.60, P<0.001 for all comparisons). Moreover, search frequency increased for sunscreen and sunburn during 2004-2016 but decreased for melanoma and skin cancer over the same time period (P<0.01).

The data also showed that searches for sunscreen/sunburn increased in the summer, whereas skin cancer/melanoma predominated during winter months. During 2004-2013, annual search data for sunscreen had a positive association with annual melanoma incidence (P=0.02), but not melanoma mortality. A trend emerged for the association between sunburn and melanoma incidence (P=0.07). Searches for sunscreen had a strong negative correlation with mortality-to-incidence ratio (r=-0.85, P=0.002).

The authors concluded that online skin cancer prevention campaigns should emphasize sunscreen and sunburn over melanoma and skin cancer but should alter the terms depending on the time of year. The negative correlation between searches for sunscreen and mortality-to-incidence ratio suggested that states with higher melanoma incidence will have more searches for sunscreen and lower mortality, adding credence to the rationale of targeting the search, the team said.