Koebner Phenomenon Is an Indicator of Vitiligo Activity and Aggression [Letter]

Dear editor

We recently read with great interest the article “Correlation Between the Koebner Phenomenon and Clinical Features in Vitiligo” by Tang¹ et al, published in your journal. This study presents that the Koebner phenomenon is associated with clinical progression, the acrofacial type, comorbid immune-related disease, and a larger lesion area of Vitiligo patients and may indicate disease activity and aggression.

The research collected 1472 Vitiligo patients from the Institute of Dermatology, Anhui Medical University and record their clinical manifestations of them. It divided the patients into two groups Koebner-positive and Koebner-negative and further compared the clinical characteristics of the two cohorts. As a result, no significant difference could be seen in age, age onset, gender, or family history between Koebner-positive and Koebner-negative groups, while the duration of disease, the percentage of patients in the progressive stage, with the acrofacial type, with comorbid immune-related diseases, with lesion area are higher in Koebner-positive group.

However, there are still some limitations in this project. Firstly, the research does not pay sufficient attention to the effect of environmental and psychological factors, which also play key roles in the progress of Vitiligo. The researchers are supposed to collect the information of the patients such as living environment, workplace, attitude towards their own illness, and expectations about the prognosis of the disease. Secondly, this was a single-center study, and ethnicities local diet, and climate may have biased the results. A multiple-center project that contains more hospitals from different cities in China will be more convincing. Lastly, the research merely focuses on the correlation between the Koebner Phenomenon and the Clinical Features of Vitiligo. The Mendelian Randomization can be used to explore the causal effect between them through the form of single nucleotide polymorphisms, providing genetic evidence for the research of Vitiligo.^2,3

In conclusion, the work by Tang et al provides novel insights into the correlation between the Koebner phenomenon and Clinical characteristics of Vitiligo. However, further effort should be placed into decreasing the effect of confounding factors and exploring the genetic causal evidence between the Koebner phenomenon and Vitiligo.