article_snippet.sent: Some sufferers have to lie down to let the pain subside.
article_snippet.sent: the condition is extremely rare and is thought to affect around 35 known people in the world.
article_snippet.sent: It's both emotionally strenuous and physically painful.
article_snippet.sent: The condition, which can in some people trigger potentially a deadly anaphylactic shock, usually gets worse as sufferers get older.
article_snippet.sent: I think I'm lucky, compared to a lot of other diseases I could have had,' Alexandra said. '
article_snippet.sent: At least this is tolerable and manageable.'