Lichen red flat-dull is a common skin lesion, a disease belonging to the group of infectious-allergic diseases. The disease occurs with characteristic signs of an immune response in the form of inflammatory elements: redness and rashes on the surface of the skin and mucous membranes. The rash that appears is accompanied by itching, burning, a feeling of tightness, and pain. Lichen ruber planus is characterized by round red spots in the form of dry clusters. Peeling is felt when touched. Photos of clinical manifestations are not normally possible, since the disease is chronic. Pathology manifests itself in any age group, including infants. Women get sick somewhat more often than men.