Treatment with betamethasone valerate 0.1% cream was found to cause significantly greater epidermal thinning than crisaborole 2% ointment, according to new study results.
The observer-blind, randomized, within-subject controlled trial involved 37 atopic dermatitis (AD) patients who applied the treatments twice daily for 4 weeks, according to the study published in JEADV Clinical Practice.
Researchers assessed skin properties using optical coherence tomography (OCT) and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy at baseline, during treatment, and after a 4-week washout period.
Key Findings
- Epidermal thinning: BMV induced 2.3 times more pathologic epidermal thinning than CRB after 4 weeks of treatment.
- Vascular changes: The depth of the superficial vascular plexus decreased significantly more with BMV compared to CRB (-20.34 μm vs -9.51 μm).
- Skin barrier integrity: Transepidermal water loss (TEWL) after tape stripping was significantly higher at sites treated with BMV than CRB (45.44 g/m2/h vs 34.13 g/m2/h).
- Stratum corneum composition: ATR-FTIR analysis revealed lower levels of carboxyl groups in the stratum corneum at BMV-treated sites compared to CRB-treated sites (P=.0252 for the 1410 cm-1 band).
- Collagen matrix changes: PS-OCT-derived collagen matrix index increased significantly more with BMV treatment compared to CRB (100.02 AU vs -3.99 AU).
Methods
The study included 37 AD patients with a median age of 23 year with clinically clear skin at the test sites. Other cohort demographics included:
- Gender: 65% female, 35% male
- Ethnicity: 70% White-UK, 8% other White background, 22% other background
- Fitzpatrick skin type: 14% type 1, 32% type 2, 38% type 3, 11% type 4, 5% type 5
Participants applied a fingertip unit of either BMV or CRB to the assigned forearm twice daily for 28 days. The average daily usage was similar for both products (2.13 ± 0.158 g for CRB and 2.12 ± 0.204 g for BMV). Skin assessments were performed on days 1, 15, 29, and 57 using the following techniques:
Results
The mean reduction in epidermal thickness from baseline to day 15 was -28.65 μm for BMV and -14.41 μm for CRB (P<.0001). TEWL changes from baseline to day 29 significantly differed between treatments, with CRB showing an increase of 2.06 g/m2/h and BMV showing a decrease of 0.52 g/m2/h (P<.0001).
ATR-FTIR analysis of skin surface carboxyl group levels showed a greater reduction with BMV treatment (-6.75 AU) compared to CRB (-4.88 AU) for the 1410 cm-1 band (P=.0252). HPLC analysis of stratum corneum NMF components on day 29 revealed significantly lower levels of urocanic acid at BMV-treated sites (0.032 nmol/μg protein) compared to CRB-treated sites (0.039 nmol/μg protein, P=.0215).
Objective skin redness decreased more with BMV treatment (-27.61 AU) compared to CRB (-1.16 AU) from baseline to day 29 (P=.0005).
The study identified superficial plexus depth and stratum corneum carboxyl group levels as the most discriminative biomarkers for TCS-induced skin changes. Conditional logistic regression analysis revealed odds ratios of 0.02424 (95% CI: 0.01291, 0.04552) for superficial plexus depth and 0.00022 (95% CI: 0.00005, 0.00105) for carboxyl groups.
Adverse events were reported in 81% of participants, with most being mild and expected for the treatments or population studied.
The authors declared the following conflicts of interest: The lead author has received fees and research funding from various pharmaceutical companies, including Pfizer, Bayer Dermatology, and Stiefel-GSK, that manufacture topical anti-inflammatory treatments for eczema. Another has served as a clinical trial Investigator and advisory board member for multiple organizations, including Pfizer, Novartis, and Regeneron. Several co-authors are full-time employees and shareholders of Pfizer, while others have no conflicts to declare.
