BACKGROUND:A novel botulinum toxin type A (Protoxin; Protox Inc.) has been developed. OBJECTIVE:To evaluate the efficacy and safety of the newly developed Protoxin compared to the approved drug onabotulinumtoxinA (OBoNT) in moderate to severe glabellar lines. METHODS:Adults with a glabellar line Facial Wrinkle Scale (FWS) score of 2 (moderate) or 3 (severe) were enrolled in the study. Subjects were randomized in a 1:1 ratio to receive either Protoxin or OBoNT. A total of 20 units of botulinum toxin was injected at five sites in the glabellar region (4 units at each site). FWS scores were assessed at baseline and at weeks 4, 8, 12, and 16 post-injection. The primary endpoint was the proportion of subjects at week 4 who had a reduction of 2 or more points in FWS and a final score of 0 (none) or 1 (mild). RESULTS:A total of 274 subjects were randomized, of whom 78.1% were female. At week 4 post-treatment, the improvement rate of glabellar lines was 62.22% in the Protoxin group and 62.96% in the OBoNT group. The lower limit of the two-sided 95% confidence interval (-12.24%) exceeded the -15% margin, confirming the non-inferiority of the new drug. Safety profiles were comparable between the two groups. CONCLUSION:Protoxin demonstrated efficacy and safety profiles comparable to those of OBoNT in the treatment of moderate to severe glabellar lines. TRIAL REGISTRATION:ClinicalTrials.gov Identifier: NCT05364580.

BACKGROUND:Lesigercept (also known as YH35324) has shown favorable safety, dose-proportional pharmacokinetics (PK), and sustained suppression of serum free immunoglobulin E (IgE) after single dosing in participants with atopy. We examined these outcomes following repeated dosing in participants with atopy or allergic diseases. METHODS:In this phase 1b study, healthy adults who had atopy, with or without mild allergic diseases, and had serum total IgE level ≥30 IU/mL (Cohorts 1-4), and adults with moderate-to-severe atopic dermatitis (Cohort 5), were enrolled and randomized. Cohorts 1, 2, and 4 received lesigercept (0.75 mg/kg at 2-week intervals [Q2W], 3 mg/kg at 4-week intervals [Q4W], and 6 mg/kg at 8-week intervals [Q8W], respectively) or placebo (6:1). Cohort 3 received lesigercept (6 mg/kg Q4W), placebo, or omalizumab (300 mg Q4W) (6:1:6). Cohort 5 received lesigercept (6 mg/kg Q2W) or placebo (2,1). All cohorts were followed for 141 days. RESULTS:Across Cohorts 1-4, participants received lesigercept (n = 25), omalizumab (n = 6), or placebo (n = 5); Cohort 5 received lesigercept (n = 6) or placebo (n = 3). Treatment-emergent adverse events (TEAEs) occurred in 15 participants in Cohorts 1-4 (lesigercept: 36.0%, omalizumab: 50.0%, placebo: 60.0%) and in 5 participants in Cohort 5 (lesigercept: 83.3%, placebo: 0%). No drug-related grade ≥3 or serious TEAEs, discontinuation, death, or anaphylaxis occurred. Lesigercept exposure (Cmax and AUClast) increased dose-dependently, and serum free IgE levels were suppressed in all lesigercept groups, with longer median durations below 25 ng/mL than placebo (10-29 versus 0 days). CONCLUSION:Lesigercept exhibited favorable safety, predictable PK, and durable serum free IgE suppression after repeated dosing, supporting further clinical development.

Atopic dermatitis (AD) is a chronic inflammatory skin disorder characterized by recurrent pruritus and epidermal barrier dysfunction. The long-term use of topical corticosteroids is limited by local and systemic adverse effects, including skin atrophy. Here, we developed a cationic lipid nanoparticle (LNP) platform for the topical delivery of bakuchiol (BKC), a hydrophobic plant-derived bioactive with potent anti-inflammatory but limited aqueous solubility and skin permeation. The formulated BKC-LNPs showed high encapsulation efficiency and stable nanoscale physicochemical properties. By promoting interaction at the negatively charged skin interface, the cationic surface design improved cutaneous delivery compared with free BKC. In vitro, BKC-LNPs suppressed NF-κB activation and reduced the expression of pro-inflammatory mediators. The formulation also demonstrated significant anti-melanogenic efficacy, addressing post-inflammatory hyperpigmentation (PIH) - a debilitating chronic sequela of AD. In a murine model of AD-like skin inflammation, topical BKC-LNP treatment reduced ear swelling, epidermal hyperplasia, and inflammatory cell infiltration, and downregulated the pruritogenic mediators IL-31 and TSLP. In addition, BKC-LNPs upregulated barrier-related markers associated with epidermal homeostasis. Together, these findings identify cationic BKC-LNPs as a promising, multi-functional non-steroidal biomaterial platform for modulating inflammation, pruritus, pigmentation, and barrier recovery of AD.

Atopic dermatitis (AD) is a chronic inflammatory skin disorder characterized by recurrent pruritus and epidermal barrier dysfunction. The long-term use of topical corticosteroids is limited by local and systemic adverse effects, including skin atrophy. Here, we developed a cationic lipid nanoparticle (LNP) platform for the topical delivery of bakuchiol (BKC), a hydrophobic plant-derived bioactive with potent anti-inflammatory but limited aqueous solubility and skin permeation. The formulated BKC-LNPs showed high encapsulation efficiency and stable nanoscale physicochemical properties. By promoting interaction with the negatively charged skin interface, the cationic surface design improved cutaneous delivery relative to free BKC. In vitro, BKC-LNPs suppressed NF-κB activation and reduced the expression of pro-inflammatory mediators. The formulation also showed significant anti-melanogenic efficacy, addressing post-inflammatory hyperpigmentation (PIH) – a debilitating chronic sequela of AD. In a murine model of AD-like skin inflammation, topical BKC-LNP treatment reduced ear swelling, epidermal hyperplasia, and inflammatory cell infiltration while downregulating the pruritogenic mediators IL-31 and TSLP. In addition, BKC-LNPs upregulated barrier-related markers associated with epidermal homeostasis. Together, these findings identify cationic BKC-LNPs as a promising, multi-functional non-steroidal biomaterial platform for modulating inflammation, pruritus, pigmentation, and barrier recovery of AD.

BACKGROUND:Submental fat (SMF) is commonly treated with liposuction, surgery, or injectable drugs. Cholic acid, a primary bile acid, can induce lipolysis. OBJECTIVES:To evaluate the efficacy and safety of MT921, an injectable cholic acid formulation, for reducing moderate to severe SMF. METHODS:Subjects with moderate to severe SMF were randomized to receive MT921 1.0%/1.0 cm, MT921 1.5%/1.0 cm, MT921 1.5%/1.25 cm, or placebo. Primary endpoints were ≥1- and ≥2-grade improvements in clinician- and patient-assessed SMF Rating Scales at 4 weeks after the final treatment. Secondary endpoints included changes in SMFRS, patient satisfaction, Patient-Assessed Submental Fat Impact Scale, and SMF volume or thickness measured by MRI or calipers. Safety was assessed by adverse events, laboratory tests, and vital signs. RESULTS:In groups 1, 2, 3, and 4, respectively, ≥1-grade improvement in clinician-assessed SMFRS was achieved by 72.73%, 88.64%, 79.07%, and 48.78% of subjects, and ≥1-grade improvement in patient-assessed SMFRS by 77.27%, 88.64%, 79.07%, and 46.34%. Compared with placebo, MT921 showed favorable improvements in SMFRS responses, patient satisfaction, PA-SMFIS, and caliper-measured SMF thickness. MRI-measured SMF volume decreased in MT921-treated groups but not in the placebo group. Adverse events were more frequent with MT921 but were mostly mild or moderate. CONCLUSIONS:MT921 showed favorable efficacy signals for reducing moderate to severe SMF and was generally well tolerated. These findings support further evaluation of MT921, particularly the 1.5% formulation, in larger phase 3 trials with longer follow-up.

BACKGROUND:Seborrheic dermatitis (SD) is a chronic inflammatory scalp disorder associated with Malassezia dysbiosis and increased sebum production. AMPamide has been suggested to have anti-inflammatory and sebum-regulating effects, but its clinical efficacy and microbiome-modulating effects in SD remain unclear. OBJECTIVE:To evaluate the clinical efficacy and scalp microbiome changes following 4 weeks of use of an AMPamide-containing shampoo in patients with SD. METHODS:In this observational study, 30 patients with SD applied an AMPamide-containing shampoo for 4 consecutive weeks. Clinical outcomes, including sebum levels and overall severity scores, were assessed. Scalp bacterial and fungal communities were analyzed to evaluate α- and β-diversity and changes in Malassezia composition. RESULTS:Treatment resulted in significant reductions in sebum levels and clinical severity scores, particularly in erythema, dandruff, and pruritus. Bacterial community composition remained largely stable, while fungal α-diversity increased, and β-diversity analysis revealed a decrease in the ratio of Malassezia restricta to Malassezia globosa. CONCLUSION:AMPamide-containing shampoo was associated with improved clinical symptoms and a shift toward a more balanced fungal community composition in patients with SD, supporting its potential as a non-steroidal therapeutic option for SD.

Background Lebrikizumab is approved to treat patients with moderate-to-severe atopic dermatitis (AD). Objectives This study evaluated the 16-week efficacy outcomes of lebrikizumab in adults and adolescents with severe AD in ADvocate trials who would be eligible for treatment based on South Korean reimbursement-like criteria. Methods This was a post-hoc analysis of pooled data from ADvocate1 (NCT04146363) and ADvocate2 (NCT04178967). Patients were randomised 2:1 to receive lebrikizumab or placebo every 2 weeks. Two non-mutually exclusive subgroups were selected based on South Korean reimbursement-like criteria: Eczema Area and Severity Index (EASI) score >= 23, AD duration >= 3 years, and previous use of any systemic treatment (ST subgroup) or previous treatment with cyclosporine or methotrexate (CM subgroup). Week-16 outcomes were Investigator's Global Assessment score of 0 or 1 (IGA [0,1]) with >= 2-point improvement, >= 50%/75%/90% improvement in EASI score (EASI 50/75/90), Pruritus Numeric Rating Scale (NRS) >= 4-point improvement, and Dermatology Life Quality Index (DLQI) >= 4-point improvement. Response rates to lebrikizumab and placebo were analysed using Cochran-Mantel-Haenszel tests. Common risk differences and 95% confidence intervals were reported. Results The ST subgroup included 322 patients, and the CM subgroup included 111 patients. More lebrikizumab-treated than placebo-treated patients achieved outcome responses. Percentage differences in favour of lebrikizumab (p < 0.01) were: IGA (0,1): ST = 25.7% (18.2%-33.1%), CM = 20.8% (7.9%-33.7%); EASI 50: ST = 42.7% (32.5%-52.9%), CM = 36.9% (19.8%-54.0%); EASI 75: ST = 40.2% (31.4%-49.1%), CM = 33.3% (19.1%-47.5%); EASI 90: ST = 27.4% (20.3%-34.5%), CM = 22.1% (11.3%-32.8%); Pruritus NRS >= 4-point improvement: ST = 34.7% (26.7%-42.7%), CM = 26.7% (14.9%-38.4%); and DLQI >= 4-point improvement: ST = 44.2% (33.2%-55.2%), CM = 39.5% (20.2%-58.8%). Conclusions In this post-hoc, exploratory subgroup analysis, lebrikizumab improved AD skin and pruritus at week 16 in adults and adolescents who would be eligible for treatment based on South Korean reimbursement-like criteria.

BACKGROUND:Botulinum toxin is a key treatment for dynamic wrinkles. OBJECTIVE:This study evaluates CKDB-501A, a botulinum toxin completely free from animal-derived components including human-serum albumin, comparing its efficacy and safety to onabotulinumtoxinA (ONA) for the treatment of moderate-to-severe glabellar lines. METHODS:In this phase 3 trial, 300 subjects with moderate-to-severe glabellar lines were randomized to receive CKDB-501A or ONA. The primary efficacy endpoint was the investigator-assessed improvement rate for frowning at week 4, defined as a ≥ 2-point improvement from baseline on the 4-point Facial Wrinkle Scale (FWS). Secondary efficacy endpoints included photo-assessed improvement rates and subjects' overall assessment and satisfaction. Safety was evaluated by the monitoring of adverse events (AEs) and neutralizing antibodies formation. RESULTS:At week 4, 80.69% of the CKDB-501A group achieved a ≥ 2-point improvement in FWS score versus 70.83% for ONA, confirming non-inferiority (95% CI: 0.09-19.55, p = 0.0491). Secondary endpoints showed no significant differences between groups, with sustained efficacy up to 16 weeks. Approximately 70% maintained at least a 1-point improvement. Photo-assessed and subjects' overall improvement and satisfaction rates were consistent with primary findings. Both treatments had comparable safety profiles, with no AEs related to the local and distant spread of toxin, hypersensitivity reactions, or neutralizing antibodies formation. CONCLUSION:CKDB-501A is a safe and effective alternative to existing botulinum toxin products for treating moderate-to-severe glabellar lines, offering benefits of improved biocompatibility and reduced risk of allergic reactions. CLINICALTRIALS:gov: NCT05804656.

BACKGROUND:An increased incidence of hair loss disorders has been noted among patients with coronavirus disease 2019 (COVID-19) and individuals vaccinated against COVID-19. However, research involving large populations on this topic is lacking. OBJECTIVE:To investigate the risks associated with developing hair loss disorders in patients with COVID-19 and individuals vaccinated against COVID-19. METHODS:This nationwide, population-based, cross-sectional study included patients diagnosed with COVID-19 and healthy individuals without a history of COVID-19 infection registered in the Korean National Health Insurance Service (NHIS) database between January 1, 2021, and December 31, 2021. COVID-19 infection and vaccine databases were integrated using this NHIS database. The odds ratios of hair loss disorders were compared using multivariate logistic regression models. RESULTS:COVID-19 infection was associated with an increased risk of total alopecia (adjusted odds ratio [aOR], 1.076; 95% confidence interval [CI], 1.002-1.156), although this association was not significant after propensity score matching. No significant associations were found between COVID-19 infection and alopecia areata or telogen effluvium. However, COVID-19 vaccination was positively correlated with total alopecia (aOR, 1.266; 95% CI, 1.191-1.346), alopecia areata (aOR, 1.243; 95% CI, 1.154-1.339), and telogen effluvium (aOR, 1.495; 95% CI, 1.133-1.974). CONCLUSION:COVID-19 vaccination was positively correlated with hair loss disorders but not COVID-19 infection. However, given the advantages of vaccines in reducing COVID-19 mortality and morbidity, alopecia may be relatively reversible and less severe. Physicians need to understand the benefits and possible side effects of the COVID-19 vaccine.

BACKGROUND:Dutasteride, a 5-alpha reductase inhibitor, is prescribed for male androgenetic alopecia (AGA) in Korea and Japan. Despite its efficacy, its use is limited by its long half-life, potent dihydrotestosterone suppression, and adverse effects. OBJECTIVE:To investigate the efficacy and safety of 0.2 mg dutasteride for male AGA. METHODS:Patients with male AGA were randomized to receive 0.2 mg dutasteride, placebo, or 0.5 mg dutasteride (2:2:1) once daily for 24 weeks. Safety and efficacy endpoints were assessed. RESULTS:Overall, 139 men were analyzed. At week 24, the change in hair count within the target area at the vertex from baseline was significantly higher in the 0.2 mg dutasteride group than in the placebo group (21.53 vs. 5.96, p=0.0072). Dutasteride (0.2 mg) treatment led to greater hair growth improvement, as assessed by investigators at week 24 (p=0.0096) and an independent panel at weeks 12 and 24 (p=0.0306, p=0.0001). For all efficacy endpoints, 0.2 mg dutasteride was as effective as 0.5 mg dutasteride. The incidence of adverse events was low and not statistically different between the 0.2 mg dutasteride and placebo groups. The limitation of this study is the limited number of participants. CONCLUSION:Low-dose (0.2 mg) dutasteride for male AGA showed significant efficacy and favorable safety profile. TRIAL REGISTRATION:ClinicalTrials.gov Identifier: NCT04825561.

BACKGROUND:Atopic dermatitis (AD) is a common skin disease with a wide range of symptoms. Due to the rapidly changing treatment landscape, regular updates to clinical guidelines are needed. OBJECTIVE:This study aimed to update the guidelines for the treatment of AD to reflect recent therapeutic advances and evidence-based practices. METHODS:The Patient characteristics, type of Intervention, Control, and Outcome framework was used to determine 48 questions related to AD management. Evidence was graded, recommendations were determined, and, after 2 voting rounds among the Korean Atopic Dermatitis Association (KADA) council members, consensus was achieved. RESULTS:The guidelines provide detailed recommendations on foundational therapies, including the use of moisturizers, cleansing and bathing practices, allergen avoidance, and patient education. Guidance on topical therapies, such as topical corticosteroids and calcineurin inhibitors, is also provided to help manage inflammation and maintain skin barrier function in patients with AD. Additionally, recommendations on conventional systemic therapies, including corticosteroids, cyclosporine, and methotrexate, are provided for managing moderate to severe AD. CONCLUSION:KADA's updated AD guidelines offer clinicians evidence-based strategies focused on basic therapies, topical therapies, and conventional systemic therapies, equipping them to enhance quality of care and improve patient outcomes in AD management.

Patients with psoriasis are vulnerable to infections due to dysregulated immunity, use of immunosuppressive drugs, and comorbid conditions. Despite ongoing concerns regarding coronavirus disease 2019 (COVID-19) vulnerability in patients with psoriasis, evidence remains limited. This nationwide, population-based, retrospective cohort study aimed to assess the risk and severity of COVID-19 and vaccine effectiveness in patients with psoriasis, including those receiving immunomodulatory therapy, using Korean National Health Insurance Service claims data from 2018 to 2021. The primary analysis included 167,746 patients with psoriasis and 866,582 controls, revealing no significant associations between psoriasis and COVID-19 (adjusted hazard ratio [aHR]: 0.99, 95% confidence interval [CI]: 0.95-1.04). Conversely, the secondary analysis of 3,131 patients with psoriasis and 265,475 controls revealed significantly higher rates of severe COVID-19 in patients with psoriasis (aHR: 1.33, 95% CI: 1.08-1.64). While some treatment subgroups - such as the cyclosporine and methotrexate subgroups - demonstrated higher incidences of COVID-19 than the reference (nonsystemic) subgroup, these differences were not statistically significant. Furthermore, vaccine interaction effects between the duration of immunity and psoriasis or each treatment were insignificant (all P > 0.05). Patients with psoriasis exhibited a higher risk of severe COVID-19; however, their COVID-19 susceptibility and vaccine effectiveness resembled those of the control group. Additionally, the use of immunomodulatory agents did not impact COVID-19 risk or vaccine effectiveness. These findings highlight the need for dermatologists to implement pre- and postinfection strategies tailored for patients with psoriasis.

BACKGROUND:Atopic dermatitis (AD) is a common skin disease with a wide range of symptoms. Due to the rapidly changing treatment landscape, regular updates to clinical guidelines are needed. OBJECTIVE:This study aimed to update the guidelines for the treatment of AD to reflect recent therapeutic advances and evidence-based recommendations. METHODS:The Patient characteristics, type of Intervention, Control, and Outcome framework was used to determine 48 questions related to AD management. Evidence was graded, recommendations were determined, and, after 2 voting rounds among the Korean Atopic Dermatitis Association (KADA) council members, consensus was achieved. RESULTS:This guideline provides treatment guidance on advanced systemic treatment modalities for AD. In particular, the guideline offers up-to-date treatment recommendations for biologics and Janus-kinase inhibitors used in the treatment of patients with moderate to severe AD. It also provides guidance on other therapies for AD, along with tailored recommendations for children, adolescents, the elderly, and pregnant or breastfeeding women. CONCLUSION:KADA's updated AD treatment guidelines incorporate the latest evidence and expert opinion to provide a comprehensive approach to AD treatment. The guidelines will help clinicians optimize patient-specific therapies.

BACKGROUND:In 2006, the Korean Atopic Dermatitis Association (KADA) working group released the diagnostic criteria for Korean atopic dermatitis (AD). Recently, more simplified, and practical AD diagnostic criteria have been proposed. OBJECTIVE:Based on updated criteria and experience, we studied to develop and share a consensus on diagnostic criteria for AD in Koreans. MATERIALS AND METHODS:For the diagnostic criteria, a questionnaire was constructed by searching the English-language literature in MEDLINE and the Cochrane Database of Systematic Reviews. A modified Delphi method composed of 3 rounds of email questionnaires was adopted for the consensus process. Fifty-four KADA council members participated in the 3 rounds of votes and expert consensus recommendations were established. RESULTS:Diagnostic criteria for AD include pruritus, eczema with age-specific pattern, and chronic or relapsing history. Diagnostic aids for AD encompass xerosis, immunoglobulin E reactivity, hand-foot eczema, periorbital changes, periauricular changes, perioral changes, nipple eczema, perifollicular accentuation, and personal or family history of atopy. CONCLUSION:This study streamlined and updated the diagnostic criteria for AD in Korea, making them more practicable for use in real-world clinical field.

Hyaluronidase has been used as an adjuvant to facilitate subcutaneous drug delivery by degrading hyaluronic acid, a viscoelastic barrier in subcutaneous tissue. However, traditional animal-derived hyaluronidases raise safety concerns, including risk of anaphylaxis and zoonoses. This study aimed to evaluate the safety, tolerability, and pharmacokinetics of ALT-BB4, a novel recombinant hyaluronidase derived from human hyaluronidase PH20, in healthy adults. This first-in-human, multicenter, randomized, double-blinded, placebo-controlled phase 1 study included 244 participants who received single intradermal or subcutaneous injections of ALT-BB4 or placebo. The study was conducted in three parts: part I assessed drug allergy reactions, part II-A evaluated pharmacokinetics, and part II-B assessed safety and tolerability. Intradermal injection of ALT-BB4 exhibited a low incidence of drug allergy reactions (0.4

BACKGROUND:Mesenchymal stem cells (MSCs) play important roles in therapeutic applications by regulating immune responses. OBJECTIVE:We investigated the safety and efficacy of allogenic human bone marrow-derived clonal MSCs (hcMSCs) in subjects with moderate to severe atopic dermatitis (AD). METHODS:The study included a phase 1 open-label trial followed by a phase 2 randomized, double-blind, placebo-controlled trial that involved 72 subjects with moderate to severe AD. RESULTS:In phase 1, intravenous administration of hcMSCs at 2 doses (1 × 106 and 5 × 105 cells/kg) was safe and well tolerated in 20 subjects. Because there was no difference between the 2 dosage groups (P = .9), it was decided to administer low-dose hcMSCs only for phase 2. In phase 2, subjects receiving 3 weekly intravenous infusions of hcMSCs at 5 × 105 cells/kg showed a higher proportion of an Eczema Area and Severity Index (EASI)-50 response at week 12 compared to the placebo group (P = .038). The differences between groups in the Dermatology Life Quality Index and pruritus numeric rating scale scores were not statistically significant. Most adverse events were mild or moderate and resolved by the end of the study period. CONCLUSIONS:The hcMSC treatment resulted in a significantly higher rate of EASI-50 at 12 weeks compared to the control group in subjects with moderate to severe AD. The safety profile of hcMSC treatment was acceptable. Further larger-scale studies are necessary to confirm these preliminary findings.

Importance The use of oral corticosteroids for prolonged periods may be associated with adverse events (AEs). Nevertheless, the risk of AEs with oral corticosteroids, especially among patients with atopic dermatitis (AD), has not been comprehensively investigated and lacks evidence on duration of treatment. Objective To assess the association between long-term exposure to oral corticosteroids and AEs among adult patients with AD. Design, Setting, and Participants This nested case-control study used data from the Health Insurance Review and Assessment Service database of South Korea between January 1, 2012, and October 31, 2021, which included 1 year prior to the cohort entry date of January 1, 2013, for assessing exclusion criteria and baseline characteristics, and 1 year after the study end date of October 31, 2020, to ensure a minimum duration for assessing exposure. Among the population of adults with AD, patients diagnosed with any of 11 AEs were matched with patients who had never received a diagnosis of any of the 11 AEs. Exposure Long-term use of oral corticosteroids was defined as cumulative supply of more than 30 days or more than 90 days of oral corticosteroid prescription per year. Main Outcomes and Measures We used multivariable conditional logistic regression analyses to measure the risk of 11 individual outcomes (osteoporosis, fracture, type 2 diabetes, hyperlipidemia, hypertension, myocardial infarction, stroke, heart failure, avascular necrosis, cataract, or glaucoma) as the composite outcome, controlling for potential confounders. We further classified the composite outcome to individual outcomes to evaluate the AE-specific risk. Results Among 1 025 270 patients with AD between 2013 and 2020, 164 809 cases (mean [SD] age, 39.4 [14.8]; 56.9% women) were matched with 328 303 controls (mean [SD] age, 39.3 [14.7]; 56.9% women) for sex, age, cohort entry date, follow-up duration, and severity of AD, where the balance of most baseline characteristics was achieved. A total of 5533 cases (3.4%) and 10 561 controls (3.2%) were exposed to oral corticosteroids for more than 30 days, while 684 cases (0.4%) and 1153 controls (0.4%) were exposed to oral corticosteroids for more than 90 days. Overall, there was no increased risk of AEs with use of oral corticosteroids for more than 30 days (adjusted odds ratio [AOR], 1.00; 95% CI, 0.97-1.04), whereas the risk was slightly higher with use of oral corticosteroids for more than 90 days (AOR, 1.11; 95% CI, 1.01-1.23). The small elevation in experiencing an AE was observed with each cumulative or consecutive year of ever long-term use. Conclusions and Relevance This case-control study found a slightly increased risk of AEs associated with use of oral corticosteroids for more than 90 days per year, which warrants future research to fully elucidate the observed findings.