Functional state of dermal circulation in patients with lichen planus
Authors: Manvelova K.A. 
Published: April 2024

Lichen planus belongs to the group of the most common dermatoses. The etiology and mechanisms of development of lichen planus are not fully understood. This dermatosis is characterized by a variety of clinical forms, as well as a chronically relapsing course, and a fairly frequent resistance to traditional therapies. The chronically relapsing course and susceptibility to complications and deterioration in the quality of life of patients with lichen planus give this dermatosis the status of a medical and social problem.
Objective — to investigate the state of blood circulation in the areas of skin lesions of patients with lichen planus, depending on the stage of the clinical course of dermatosis.
Materials and methods. We observed 37 patients with lichen planus with a typical (classical) clinical form (22 men and 15 women) aged 20 to 44 years. The comparison group consisted of 30 apparently healthy individuals, comparable by sex and age. In 19 patients, the progressive stage of dermatosis was diagnosed, in 18 — the stationary stage. The duration of the course of the disease in the subjects ranged from two weeks to six months. In all the examined patients, the microcirculation index (MI), the mean quadratic deviation of the microcirculation indicators, the coefficient of variation (KV), as well as maximum amplitude of slow oscillations (ALF), maximum amplitude of rapid oscillations (AHF), maximum amplitude of pulse oscillations (ACF) were determined. The first component of the active mechanism of regulation of tissue circulation was calculated according to the formula ALF/PM; the second component — according to the formula σ/ALF; the first component of the passive mechanism of modulation of tissue circulation was calculated according to the formula ACF/σ; the second component — according to the formula AHF/σ. In addition, the intravascular resistance ACF/PM · 100 % and the microcirculation efficiency coefficient ALF/(AHF + ACF) were studied. The study was carried out on a Doppler flowmeter Vingmed SD-100 (Sweden).
Results and discussion. The obtained results indicate a low level of tissue perfusion, insufficient functioning of tissue blood circulation modulation mechanisms and reduced vasomotor activity of microvessels in the areas of affected skin of patients with lichen planus. It was also established that the modulation of tissue blood circulation was redistributed in the direction of reducing the passive mechanism, that is, in the direction of disturbances of cardiac and respiratory rhythms of fluctuations.
Conclusions. In the examined patients with a typical (classical) form of the clinical course of lichen planus, a stagnant­static type of hemodynamics in the dermis was established during the examination by laser Doppler flowmetry in the skin areas affected by a specific papular rash.It has also been proved that in patients with lichen planus, in particular, in skin areas with specific lichenoid lesions, there is a redistribution of modulation of tissue blood circulation towards a decrease in the passive mechanism, that is, towards cardiac and respiratory rhythm disorders of fluctuations.The established disorders of dermal vascularization in the areas of skin lesions of patients with lichen planus expand the understanding of the pathogenesis of this dermatosis and need to be taken into account when developing the tactics of its complex, individualized therapy, which will contribute to increasing the effectiveness of treatment.