Dear Editor,

Palmoplantar psoriasis is a type of psoriasis which predominantly involves palms and soles. Current therapeutic effects are limited with potentially significant adverse effects.1 We read with interest this study, “Methotrexate monotherapy versus methotrexate and apremilast combination therapy in the treatment of palmoplantar psoriasis: A prospective, randomised, assessor-blinded, comparative study” published in your journal.2 This was a prospective, randomized, assessor-blinded comparative study where 60 patients with palmoplantar psoriasis were randomly divided into two groups, one receiving methotrexate monotherapy and the other receiving methotrexate and apremilast combination therapy. The treatment lasted for 16 weeks. The primary efficacy endpoint was the change in the severity of skin lesions after treatment. Safety assessments included monitoring and recording adverse events. The results showed that the combination therapy group had a significantly higher reduction in the severity of skin lesions after 16 weeks of treatment. The incidence of adverse events in the two groups was similar. Future research will help further explore the mechanism of combined treatment with methotrexate and apremilast, and optimise dosage and treatment duration. In addition, methotrexate has certain nephrotoxicity, and the use of methotrexate in combination with other compounds to reduce its toxic side effects is also one of the future research directions.3

The study period for this article was relatively short. The study used a 16-week treatment period and only conducted one follow-up assessment; therefore, the study results only represent the efficacy and safety of early treatment. Palmoplantar psoriasis is a chronic disease that requires long-term maintenance and management, and therefore this short-term, randomized controlled study cannot fully reflect the long-term efficacy and safety of treatment.4

Blinding of evaluators is an advantage of this study, but it did not explain how the blinding of evaluators was implemented, such as whether a double-blind design was used, or whether the evaluators were trained.4 This information is essential for assessing the reliability and effectiveness of the study. The similar incidence of side effects reported in this study does not necessarily mean that the side effects of the two treatment regimens are completely the same, as the sample size of the study is small and may not fully reflect the side effects of the treatment regimen.5 Therefore, when using these two treatment regimens, it is still necessary to closely monitor the possible side effects and adverse reactions in patients. However, overall, this is a high-quality original article that is worth studying.