Dermographism on the shoulder. Literally, dermographism means writing on the skin. After scraping the skin with a blunt instrument the site is flushed red and urticarial wheal will emerge within 1 to 15 minutes. The sign disappears just as quickly as it emerged. Even the slightest rubbing provokes the itch. At the surgery, the patient usually only complains about the itching while the skin looks perfectly healthy. Scraping the skin with a blunt tip of a pen may depict the diagnosis after a short while of waiting.
Picture: Raimo Suhonen
Primary/Secondary Keywords