article_snippet.sent: This is a type of urticaria, or hives - where a raised, itchy rash appears on the skin at the slightest pressure.
article_snippet.sent: It is thought to be caused when the cells under the surface of the skin release histamines as part of an allergic reaction, causing the skin to swell.
article_snippet.sent: Dermographism or 'skin writing' is a type of urticaria, or hives - where a raised, itchy rash appears on the skin.
article_snippet.sent: Dermatographia is thought to be caused when the cells under the surface of the skin release histamines under the slightest pressure.
article_snippet.sent: Histamines are chemicals released in the body as part of an allergic reaction, causing the skin to swell.
article_snippet.sent: In this type of urticaria, itchy weals occur after friction such as rubbing or stroking the skin.
article_snippet.sent: This itching may be aggravated by heat.
article_snippet.sent: Dr Tabi Leslie, from the British Association of Dermatologists, explained that dermographism or 'skin writing' is a type of urticaria.
article_snippet.sent: Dr Waller said: 'Raised red weals, which are caused by the release of histamine from cells in the skin called mast cells, appear at sights of friction, such as rubbing or stroking of the skin. '
article_snippet.sent: This itching may also be aggravated by heat. '
highlights_snippet.sent: Condition is a type of urticaria - where an itchy rash appears after pressure .
  