Vidal's Lichen

VIDAL'S LICHEN (lichen Vidal, lichen chron. simplex, neurodermitis Brocq, prurigo circumscr., dermatit. pruriens Neisser), clinical syndrome, isolated from the group of lichens by E. Vidal and described in detail by L. Brocq and Jacquet (1891). The disease has three stages. 1. Stage of primary itching - characterized by itching on a limited area of unchanged skin, occurring in attacks, mainly in the evening or at night, and irresistibly prompting scratching. 2. Papular stage, or lichenificative stage, is expressed in the fact that under the influence of scratching, the skin reddens, pigments, and becomes covered with scattered small, slightly elevated papules, indistinctly outlined, sometimes round, sometimes polygonal, more often with a flattened and under lateral lighting weakly shiny surface. Individual papules are covered either with loosened horny layer or with blood crust. In places, the skin grooves are deepened, so that the latter appears as if traced by thin lines intersecting at acute, obtuse or right angles. On palpation, the skin is fine-grained, dry, hard, but not thickened. 3. Stage of diffuse lichenification, infiltration (Brocq) represents a more or less limited, elevated, disk of various shades of pink-brown color of thickened skin, which is traced by long, deep parallel grooves intersecting at different angles, dividing the surface of the disk into fields of various sizes in the form of squares, rectangles, rhombuses, triangles, etc., covered either with thin scales, or with abrasions, or with blood crusts. The skin is thickened, dense, hard, dry. The size and shape of the disks are diverse [see separate table (Vol. IV, p. 759-760), Fig. 1].-The course is chronic, the disease lasts for months, years; it can disappear spontaneously, leaving a pigmented, less frequently achromic spot. Seasonal improvements and exacerbations are possible. The number of disks is usually small-1, 2, 3. Favorite locations- the back of the neck, large joint flexures, genital and perigenital parts, intergluteal fold, etc. Symmetrical localization is often observed. Variations of the clinical picture: 1) follicular form of Fox-Fordyce, (see); 2) linear form; as local complications, eczematization is often observed, less frequently impetiginization, which in skin folds is facilitated by local, mainly fungal infection. Histologically-in the epidermis, hyperkeratosis, parakeratosis and weak alteration cavitaire and spongiosis are observed, but without blister formation; in the skin-papillomatosis, swelling of collagen and elastin, thickening of vessel walls and gradually increasing infiltrate, mainly of the papillary and subpapillary layers.-Differential diagnosis-with lichen planus, secondarily lichenified dermatoses, in particular, mycosis fungoid.-For pathogenesis, the following facts are important: 1) primary itching, i.e., pure hyperesthesia on clinically and histologically unchanged (Marcuse) skin; 2) development of objective changes under the influence of local mechanical irritations and their intensification with the duration of the latter; 3) reverse development of the infiltrate with the decrease of itching and scratching; 4) according to Golay, applying a bandage to the itching area, without eliminating the itching, but preventing scratching, prevents lichenification; 5) itching, even persistent and stubborn, does not lead to lichenification in everyone; 6) V. l. affects, mainly, townspeople of middle age, sedentary lifestyle, intellectually overworking, neuro- and psychasthenics, abusing coffee, tea, alcohol, tobacco, etc. Thus, the basis of the dermatosis is a sensitive functional neurosis manifested by itching; the latter is caused by local and general causes, especially intoxications and auto-intoxications due to secretory digestive disorders acting through the autonomic, and possibly hormonal system. The individual ability of the skin to react to scratching with lichenification may also be the basis of the dermatosis.-Treatment. When localized at natural openings-elimination of all local causes that can cause itching-hemorrhoids, cracks around the anus, worms, prostatitis, vaginitis, local infections, etc. In multiple and symmetric V. l.-regulation of excretory organs, especially elimination of secretory digestive disorders, proper regimen and diet, along with attempts at desensitization, general hydrotherapy, etc. Local treatment: symptomatically-anti-itching ointments, solutions, etc. More reliable is physiotherapy-static baths, d'Arsonvalization. In the period of diffuse lichenification, first place is given to X-rays and snow CO₂, sometimes ultraviolet therapy. In nervous parasymphilitics-specific treatment.