Lichen Simplex Chronicus in a Nut-ShellLichen Simplex Chronicus (LSC), also called as neurodermatitis circumscripta is a chronic skin disease characterized by lichenified plaques, which occur as result of constant scratching or rubbing of skin [1]. LSC is not a primary process. Rather, a person senses pruritus in a specific area of skin (with or without underlying pathology) and causes mechanical trauma to the point of lichenification.Patients with LSC usually describe stable pruritic plaques on one or more areas; however, LSC is found on the skin in regions accessible to scratching. Those regions include the following: scalp, nape of neck, extensor forearms and elbows, vulva and scrotum, upper medial thighs, knees, lower legs, and ankles [2][3][4]. LSC tends to occur in adults, especially those between 30 and 50 years of age, and women are more commonly affected than men [5].Pruritus is the predominant symptom that leads to the development of LSC. It is often paroxysmal and typically worse at night [5]. Frequent triggers include mechanical irritation (e.g., from clothing), environmental factors, such as heat and sweating, and psychological factors, such as stress and anxiety. Furthermore, emotional tensions, as seen in patients with anxiety, depression, or obsessive-compulsive disorder, may play a key role in inducing a pruritic sensation, leading to scratching that can become self-perpetuating [6,7]. Despite pruritus provokes rubbing that produces clinical lesions, the exact underlying pathophysiology of LSC remains unknown.The typical presentation of LSC is a circumscribed, lichenified, pruritic plaque. Scales and excoriation are often present. Changes in pigment also occur, most notably in darker-skinned individuals. Both hypo-and hyperpigmentation have been described, although the most common finding is a dusky violaceous or brown hyperpigmentation [5,8]. While LSC usually arises on normal-appearing skin, some skin types are more predisposed to lichenification, such as skin that tends toward eczematous conditions (i.e., atopic dermatitis, atopic diathesis) [1]. Figures 1, 2 and 3 present three cases of LSC. Figure 4 shows LSC histopathology.
