Lichen simplex chronicus = الحزاز البسيط المزمن |
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Lichen Simplex Chronicus
The vast majority of patients with pruritus who chronically rub the skin may develop lichen simplex chronicus. It often develops in the setting of atopic dermatitis or allergic contact dermatitis. thick plaques often with excoriation, the normal skin markings accentuate producing the finding known as lichenification. Uncommonly, some patients develop macular or lichen amyloidosis. Some patients, due to the character of their underlying disease such as dermatitis herpetiform is, only rarely develop lichen simplex chronicus. Lastly, skin with severe chronic dermatoheliosis does not develop typical lichen simplex chronicus.
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Histopathology.
Lichen simplex chronicus is the prototype for chronic dermatitis . There is hyperkeratosis interspersed with areas of parakeratosis, acanthosis with irregular elongation of the rete ridges, wedge-shaped hypergranulosis, and broadening of the dermal papillae. Slight spongiosis may be observed, but vesiculation is absent. Minimal papillomatosis is sometimes present. Excoriations, which are punctate ulcerations lined by
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necrotic superficial papillary dermis, fibrin, and neutrophils, are often present; however, they are often present in many pruritic dermatoses. There may be a sparse superficial perivascular infiltrate without
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exocytosis. In the papillary dermis, there are an increased number of fibroblasts and vertically oriented collagen bundles. As rubbing increases in intensity and chronicity, epidermal hyperplasia becomes more florid and the fibrosis more marked. Searching for features of dermatitis associated with chronic rubbing and scratching may give a hint as to the initial underlying dermatitis.
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