Algorithm of topical oxidant application in the treatment of seborrheic keratosіs based on ultrasound and pathomorphological features

Objective — to develop an algorithm for the use of a topical oxidizing agent (hydrogen peroxide) in the treatment of seborrheic keratosis (SK), taking into account the ultrasound (US) and pathomorphological data and using statistical models. Materials and methods. 35 patients aged 35 to 75 (32 (91.4 %) women and 3 (8.6 %) men) with seborrheic keratomas were examined on the basis of «University Clinic» Medical Educational and Scientific Center of Zaporizhzhia State Medi­cal University. Clinical, dermatoscopic and pathomorphological research methods were used for diagnostic purposes. To determine the thickness of keratosis, an ultrasound scan was performed. Results and discussion. Topical adapalene was applied locally to SK foci for 2 weeks, 2 times a day in 35 patients. After retinoid administration, the thickness of most foci decreased (n = 26; 74.3 %), but some of them did not change significantly (n = 9; 25.7 %). For the purpose of chemical destruction, it was recommended to use a topical oxidant — 30 % solution of hydrogen peroxide. Group 1 (application of topical oxidant in one cycle) included 20 patients who used the remedy for 5—6 days. The duration of treatment for ≥ 7—10 days was recommended for 15 patients of group 2. A comparison of keratoma thickness in patients of both groups with different duration of oxidant use revealed a statistically significant difference between subgroups (U = 88.500; p < 0.05). The greater the thickness of the keratoma was, the more it needed additional application of hydrogen peroxide. Taking into account the pathomorphological and ultrasound signs, a discriminant analysis was performed between groups of patients with 1 and 2 cycles of hydrogen peroxide application. In case of less than 0 index, longer therapy was recommended. Conclusions. The scheme using topical oxidant is a promising area of treatment for patients with SK and requires further study. The application of statistical methods made it possible to identify the main variable features (pathomorphological variant and keratoma thickness), which determine the choice of the duration of hydrogen peroxide application.