Introduction: Venous ulcers are difficult to heal chronic wounds. Most challenging are the non-healing and recurrent ulcers, because of which we are seeking for therapies that stimulate and support their healing. Aim: To assess the efficacy of fish collagen and its impact on the process of healing of venous leg ulcers. Material and methods: This 12-week randomized single-centre study included a total of 97 adults with venous leg ulcer, randomized into two groups: the study group (n = 48) and the control group (n = 49). All patients received specialist medical care including skin and limb care, wound development according to the TIME scheme (tissue debridement, infection and inflammation control, moisture balance, edge) and short-stretch bandage compression (compression class II). In addition, the study group received tropocollagen gel applied to the skin around the wound. Every 2 weeks we evaluated the wound surface and temperature distribution on the shin (average temperature, median, minimum and maximum) -symmetrically on the sick and healthy limb. Results: We observed a greater number of complete ulcer healing in the study group (week 12: 29.2% vs. 22.4%; week 24: 52.1% vs. 36.7%). Faster healing time in the study group was observed in both big and small ulcers. The thermographic analysis showed statistically significant reduction in periwound inflammation among patients from the study group (p < 0.05). Statistically significant reduction in mean as well as maximum values of limb temperature occurred only in the study group (Tx: R = 0.37, p < 0.001; Tmax: R = 0.40, p < 0.001). Conclusions: Thermographic analysis showed better wound healing effects in the group using tropocollagen. Significant impact of collagen on the healing process was observed only after 8 weeks of application.

In the presented study, the transdermal results from the areas surrounding the ulcerated skin areas were compared with those obtained from healthy skin tissue. The analysis of electrical parameters, such as the slope of the Nyquist plot, min. IM, min. RE, min. f, Imagine part index, Phase index, Real part index, and Magnitude index were conducted. Electrical parameters have been measured in the group without lower leg ulceration and in the group with lower leg ulcers. On the basis of the statistical analysis, it was determined that these parameters may be effective in the evaluation of the skin. In fact, the skin surrounding the ulceration was characterised by different values of electrical parameters as compared with healthy skin tissue. A statistically significant difference was found in the electrical parameters obtained for the healthy leg skin and the skin surrounding the ulceration. This study was to investigate the applicability of electrical parameters in the evaluation of the skin in lower leg ulcers. The electrical parameters can be used as an effective tool in assessing the condition of the skin, both healthy and surrounding the ulcerations. The most useful parameters in assessing skin condition using electrical parameters include min. IM, min. RE, min. f, Imagine part index, Phase index, and Magnitude index.