Introduction: Enlarged facial pores are a common cosmetic concern caused by excessive sebum production, visible hair shafts, and a reduction in skin elasticity, leading to a decrease in skin quality and overall appearance. Various treatment modalities have been explored to address this issue. This study focuses on the efficacy and safety of combining Onabotulinumtoxin A (OnaBoNT-A) and hyaluronic acid filler (HA filler) to target enlarged facial pores in Asians. Materials and Methods: This study aimed to compare the efficacy and safety of OnaBoNT-A monotherapy in combination with HA filler for the treatment of enlarged facial pores. This study was a prospective, randomized, single-blinded, split-face, controlled trial that enrolled 32 subjects with visibly enlarged pores on both cheeks. One side of the face received intradermal injections of OnaBoNT-A, while the other side received OnaBoNT-A in combination with intradermal hyaluronic acid filler injection. The outcomes were measured by pore volume, visual assessment, pain score, improvement score, and side effects at various time intervals up to 24 weeks. Results: This study investigated the effects of onaBoNT-A monotherapy or in combination with HA filler on facial pore size and skin roughness. The results showed that both sides exhibited a reduction in pore volume and skin roughness over time, but the side treated with onaBoNT-A monotherapy had a slightly better improvement than the combination side at the 6-month follow-up. Subjects with histories of facial oiliness were more likely to respond to onaBoNT-A monotherapy, while those without histories of facial oiliness were more likely to respond to the side treated with combined treatment. The most common adverse events were erythema, bruising, and edema, which were more frequent on the combination side. Additionally, 18 subjects (56.25%) experienced a palpable lump on the combination side, which resolved in most cases within a few months. Conclusion: BoNT-A and HA dermal filler had a role in reducing pore size. Nonetheless, individuals with enlarged pores who exhibited beneficial effects to botulinum toxin injection typically had a background of facial oiliness. Adverse incidents like dermal edema and palpable nodules were observed, underscoring the significance of meticulous patient selection and accurate injection technique.

The intradermal route has emerged as a dose-sparing alternative during the coronavirus disease 2019 (COVID-19) pandemic. Despite its efficacy in healthy populations, its immunogenicity has not been tested in immune-mediated dermatologic disease (IMDD) patients. This assessor-blinded, randomized-controlled, non-inferiority trial recruited patients with two representative IMDDs (i.e., psoriasis and autoimmune bullous diseases) to vaccinate with fractionated-dose intradermal (fID) or standard intramuscular (sIM) BNT162b2 vaccines as a fourth booster dose under block randomization stratified by age, sex, and their skin diseases. Post-vaccination SARS-CoV-2-specific IgG and interferon-γ responses measured 4 and 12 weeks post-intervention were serological surrogates used for demonstrating treatment effects. Mean differences in log-normalized outcome estimates were calculated with multivariable linear regression adjusting for their baseline values, systemic immunosuppressants used, and prior COVID-19 vaccination history. The non-inferiority margin was set for fID to retain >80% immunogenicity of sIM. With 109 participants included, 53 received fID (all entered an intention-to-treat analysis). The fID demonstrated non-inferiority to sIM in humoral (mean outcome estimates of sIM: 3.3, ΔfID-sIM [mean, 95%CI]: −0.1, −0.3 to 0.0) and cellular (mean outcome estimates of sIM: 3.2, ΔfID-sIM [mean, 95%CI]: 0.1, −0.2 to 0.3) immunogenicity outcomes. Two psoriasis patients from the fID arm (3.8%) developed injection-site Koebner’s phenomenon. Fewer fID recipients experienced post-vaccination fever (fID vs. sIM: 1.9% vs. 12.5%, p = 0.027). The overall incidence of disease flare-ups was low without a statistically significant difference between groups. The intradermal BNT162b2 vaccine is a viable booster option for IMDD patients troubled by post-vaccination fever; its role in mitigating the risk of flare-ups remains unclear.