Background Low catalase levels and cellular vacuolation in the epidermis of patients with vitiligo support major oxidative stress in this compartment. There is now in vivo evidence for increased epidermal hydrogen peroxide (H2O2) accumulation in this patient group by utilizing noninvasive Fourier Transform Raman spectroscopy (FT Raman). Epidermal H2O2 can be removed with a topical application of narrow band UVB activated pseudocatalase cream (PC-KUS). (Mn/EDTA-bicarbonate complex, patent No. EPO 58471 1 A), yielding initiation of repigmentation. Dead Sea climatotherapy is another successful treatment modality for vitiligo, but the mode of action has escaped definition so far.

Methods Epidermal hydrogen peroxide (H2O2) was assessed in vivo before and after 21 days treatment at the Dead Sea using noninvasive Fourier-Transform Raman spectroscopy. The effectiveness of repigmentation was followed in 59 patients with vitiligo by comparing Dead Sea climatotherapy alone with the combination of Dead Sea climatotherapy/pseudocatalase cream (PC-KUS) as well as Dead Sea climatotherapy/placebo cream. Clinical repigmentation was documented by standardized black/white photography using non-UV coated bulbs as flashlight and by color photography.

Results This study on 59 patients who had vitiligo for an average time of 17 years (range 3–53 years) confirmed in vivo H2O2 accumulation in mM concentrations in the epidermis of untreated patients. Furthermore, we demonstrated a pseudocatalase activity after 15 min of Dead Sea bathing, but the decrease of epidermal H2O2 levels was significantly less compared to narrowband UVB activated pseudocatalase cream (PC-KUS). Initiation of repigmentation was already observed between day 10 and day 16 after a combination of Dead Sea climatotherapy/pseudocatalase cream compared to conventional pseudocatalase monotherapy (8–14 weeks) and Dead Sea climatotherapy alone (5–6 weeks).

Conclusion The results of this study show a significantly faster initiation of repigmentation in vitiligo after a combination of short-term climatotherapy (21 days) at the Dead Sea in combination with a pseudocatalase cream (PC-KUS) compared to either conventional climatotherapy at the Dead Sea alone or with placebo cream in combination with climatotherapy. This combined therapy is significantly faster in repigmentation than narrowband UVB activated pseudocatalase cream (PC-KUS) treatment alone.

The results of this study support the necessity of epidermal H2O2 removal as well as the influence of solar UV-light in the successful treatment of vitiligo.