Koebner Phenomenon Used to Predict Vitiligo Activity and Prognosis

Nyoman Suryawati, PhD

Recent data from Indonesia on vitiligo suggested that the Koebner phenomenon could be used to predict activity and prognosis by evaluating the clinical features of the disease, which in turn could aid in selecting appropriate modalities of therapy.

The Koebner phenomenon, defined as the development of pathologic lesions of traumatized skin in unaffected or normal areas of the body, has been present in skin conditions such as vitiligo, psoriasis, and lichen planus.

Its prevalence is reported to be around 21%-62%, though prior to the study the clinical role of the phenomenon was unclear.

This prompted investigators led by Nyoman Suryawati, , Department of Dermatology and Venereology, Sanglah Hospital Denpasar Bali, to prove the association between Koebner phenomenon with the multitude of clinical characteristic factors in vitiligo.

The Methods

The research conducted by Suryawati and colleagues was an observational analytical study with cross-sectional study design. It was conducted from September to December of 2017.

The investigators recruited a total of 60 patients who visited the Dermatology and Venereology Clinic at Sanglah Hospital in Bali. Patients were divided between 2 vitiligo groups, 1 of which included the presence of Koebner phenomenon.

All subjects with vitiligo were clinically diagnosed and examined by investigators using wood lamps. The most common form of vitiligo was vitiligo vulgaris (43.3%).

Additionally, sample characteristics data were obtained from each participant through questionnaires that included demographic and clinical data. Data was comprised of the type of vitiligo, lesion location, duration, the initial location of vitiligo lesion, lesion area and age onset of the disease.

Total Vitiligo Disease Activity (VIDA) scores were also collected.

Once the available data were obtained, they were analyzed using the Statistical Package for the Social Sciences (SPSS), and median and inter-quartile range (IOQ) was presented for quantitative variable.

Frequency variables and percentages were also obtained for qualitative variables. The Mann Whitney test was used to compare mean differences between the 2 groups.

The Findings

Suryawati and colleagues reported a significant difference in vitiligo with Koebner phenomena compared to vitiligo without regarding duration of illness (p<0.001), lesion area of vitiligo (p><0.001), degree of severity (VASI score) p><0.001, disease activity (VIDA score) p><0.001 and age at the onset of vitiligo p><0.001), degree of severity (VASI score, p<0.001, disease activity (VIDA score) p><0.001 and age at the onset of vitiligo p><0.001).

The total area of vitiligo lesion based on the rule of 9 had a significant difference between vitiligo with Koebner phenomena and without (p<0.001).

Investigators stated the finding was supported by a theory presented in the study regarding generalized vitiligo that was triggered by a complex interaction between stress and trauma

Additionally, length of illness for more than 5 years had a significant relation to vitiligo with Koebner phenomena, which suggested that the phenomenon could be used as an indicator of active vitiligo in patients.

Likewise, a significant relationship between age onset of vitiligo with Koebner phenomena was recorded (RP=8.85; 95% CI (2.48-31.52); p<0.001), which investigators reported meant that participants with age onset of illness £ 17 years old were at 8.85 times greater risk of Koebner phenomena events.

Koebner phenomena in patients with vitiligo was also suggested for defining clinical parameters predicting prognosis.

“Koebner phenomenon can be used to predict activity and prognosis by evaluating the clinical features of vitiligo that can help to choose the modalities of therapy in vitiligo patients,” the team wrote. “Further research is needed with larger sample quantities to explain the clinical characteristics of KP.”