Lichen simplex

This is regarded as a localised form of atopic eczema in which there are well demarcated areas of chronic lichenified dermatitis due to primary excessive scratching (1). It is more common in adults, with women being affected more often than men. There is frequently a personal or family history of atopy. It is relatively uncommon and should be diagnosed only once other more common causes such as contact dermatitis have been excluded

Triggers of the condition include (2):

• psychological distress
• local environmental problems such as:
  • sweating
  • heat
  • excess dryness

The condition may also develop superimposed on various anogenital conditions such as candidiasis, psoriasis, tinea cruris, lichen sclerosus, and neoplasia (2).

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Reference:

• (1) Lotti T et al. Prurigo nodularis and lichen simplex chronicus. Dermatol Ther. 2008; 21(1):42-6.
• (2) Lynch PJ. Lichen simplex chronicus (atopic/neurodermatitis) of the anogenital region. Dermatol Ther. 2004;17(1):8-19