In this study, all 22 subjects complied with the treatment protocol, and none experienced adverse events such as a burning or stinging sensation, swelling, contact dermatitis caused by mometasone furoate cream, delayed wound healing, or cutaneous infection at the application site. Compared to previous literature, our study did not reveal significant atrophogenic effects of mometasone furoate when assessed clinically and ultrasonographically.
There have been ongoing debates regarding the use of TCS and its potential for causing skin atrophy. Dykes et al. found no significant changes in skin thickness after 8 weeks of using fluticasone propionate 0.05% cream, also a potent topical corticosteroid, in 40 healthy adults, with only a 0.01-mm reduction (3%) compared to baseline (
10). On the other hand, Korting et al. reported the skin-thinning effect of mometasone furoate 0.1% ointment with twice-daily application for 6 weeks without occlusion in 24 healthy adults, guided by 20MHz B-scan ultrasonography (
11). Total skin thickness reduced by 12% on day 22 and 17% on day 29, compared to baseline (
11). While previous literature has mostly focused on the relationship between TCS and their atrophogenic effects in healthy adults, our study added essential information regarding children with moderate-to-severe AD who require repeated use of TCS due to the chronic, relapsing nature of AD.
Topical corticosteroids exert inhibitory effects on fibroblasts, reducing the production of ground substance, type I, and type III collagen, thus decreasing dermal thickness (
12). The severity of skin atrophy is determined by the potency of TCS, the frequency and duration of use, the anatomical area treated, and the vehicle used, such as ointment, cream, lotion, and gel (
12). Mometasone furoate 0.1% cream is a potent steroid derived from hydrocortisone, designed to improve efficacy (
11). Mometasone furoate exhibits greater anti-inflammatory activity and a longer duration of action compared to betamethasone (
13). It is generally well-tolerated with only transient local adverse effects (
13). Due to high lipophilicity and rapid hepatic biotransformation into 3 different metabolites with minimal intrinsic activity, it has low systemic availability via percutaneous absorption and has no significant effect on the hypothalamic-pituitary-adrenal axis (
13). Moreover, mometasone furoate has a lower affinity toward dermal cells compared to epidermal cells, owing to its ester hydrolysis biotransformation in the skin (
13). This contributes to its low corticosteroid receptor binding, resulting in minimal atrophogenicity (
13). Chlorination at position-21 and esterification at position-17 enable mometasone to penetrate the stratum corneum to reach therapeutic concentrations in the skin without causing skin atrophy. Overall, mometasone furoate is an efficacious, potent corticosteroid with a low risk of local and systemic side effects (
13). These features are hypothesized to contribute to its lower atrophogenicity.
In a systematic review by Li et al., steroid phobia among adult AD patients, parents, and caregivers of pediatric patients with AD ranged from 21.0% (95% CI, 15.8 - 26.2%) to as high as 83.7% (95% CI, 81.9 - 85.5%) (
14). Lee et al. concluded that more patients with topical corticosteroid (TCS) phobia reported partial adherence to treatment (49.4%) and non-adherence (14.1%) (
15). In comparison, patients without TCS phobia reported partial adherence in 29.3% of cases, while non-adherence was only 9.8% (
15).
Five of the studies included in Li et al.'s research surveyed patients and caregivers about their concerns regarding TCS (
14). The main concern reported regarding TCS was skin thinning (
14). In our study, we did not observe any patients with evidence of skin thinning, both clinically and radiologically. The continuous use of mometasone furoate 0.1% cream for 6 weeks on the volar aspect of both forearms did not reveal any visible telangiectasia or increased skin transparency under dermoscopy. All 22 participants were directly observed for compliance with mometasone furoate cream application twice daily throughout the study period. Our study underscores the importance of vigilant clinical monitoring for signs of skin atrophy, as we did not observe any complications associated with the use of potent TCS in children during this study. Our clinical findings and dermoscopic examinations were further supported by ultrasonographic measurements of dermal and total skin thickness, which did not show any statistically significant reduction.
Lax et al. conducted a meta-analysis to compare the safety and effectiveness of different strategies for using TCS in the treatment of AD in children and adults (
16). Sixty-three trials involving children with moderate-to-severe AD compared different potencies of TCS over a span of 1 to 5 weeks (
16). Potent TCS resulted in a high treatment success rate of 70% compared to mild-potency TCS (
16). Among the clinical trials that tested the treatment of eczema flare-ups, only 26 cases out of 2266 participants reported skin thinning (1%). These cases were associated with the use of higher-potency TCS: 16 with very potent, 6 with potent, 2 with moderate, and 2 with mild-potency steroids (
16).
Smith et al. conducted cross-sectional surveys to assess the knowledge and attitudes regarding TCS use in pediatric AD among pharmacists (n = 292) and general practitioners (GPs) (n = 257) (
17,
18). Only 27% of pharmacists and 46.9% of GPs would instruct parents to use TCS until remission (
17,
18). Over half, 54% of pharmacists and 37.6% of GPs, advocated for sparing use of TCS (
17,
18). Forty-six percent of pharmacists and 30.2% of GPs believed that skin atrophy was the most common side effect, and 56% of pharmacists also felt that side effects were unavoidable, even when TCS was used appropriately as directed by the treating physician (
17,
18). Sixty-seven percent of pharmacists and 40.7% of GPs instructed parents not to exceed 2 weeks of continuous TCS use (
17,
18). Contradictory messages from dermatologists, doctors, and allied health personnel may contribute to parental steroid phobia, treatment non-adherence, and poor treatment outcomes (
17,
18). Our study demonstrated that potent TCS could be used continuously for more than 2 weeks in the pediatric population without clinical signs of skin atrophy. Evidence-based education among doctors and allied health personnel regarding potent TCS use in children is crucial for improving treatment compliance in this chronic, relapsing-remitting disease.
5.1. Strengths and Limitations of the Study
We conducted a prospective examination of the atrophogenicity of potent TCS, both clinically and radiographically, in children with moderate-to-severe AD over a 6-week duration. However, as a pilot study, we acknowledge some important limitations, including our small sample size. The major limitation of our study is that it was a prospective cohort study rather than a double-blinded, randomized controlled trial with a control group of healthy children without AD.
The use of the GE S7XD Clear L18Hz machine with a linear probe may have posed challenges in accurately measuring the epidermis and scale crust at the stratum corneum. This could possibly explain why we observed a good clinical response without a significant reduction in epidermal thickness in our patients.
Future studies should consider comparing different treatment durations, including periods beyond 6 weeks or even 12 weeks. Additionally, exploring different vehicles of topical mometasone furoate, other potent steroids, placebo, and topical calcineurin inhibitors may provide further insights into the atrophogenic effects of TCS in children with AD.
In conclusion, our study suggests that potent TCS like mometasone furoate 0.1% cream can be safely used in children with moderate-to-severe AD when used appropriately. Skin atrophy was not observed in our study, both clinically and radiographically, when topical non-occlusive mometasone furoate 0.1% cream was used continuously for 6 weeks. Regular clinical assessments by the treating physician, along with consistent messages on potent TCS use from all healthcare providers, are vital to alleviate parental steroid phobia and enhance treatment adherence.