ICD-11 definition : Paroxysmal extreme pain disorder is a rare disorder of abnormal pain sensation. This
condition presents in the first year of life with episodes of severe rectal pain following
bowel movements. This is often accompanied by reflex anoxic seizures (RAS). Finally
there is a colour change down one half of the body; either horizontally from the waist
down or involving one half of the body as in the harlequin phenomenon.;
Paroxysmal extreme pain disorder is a rare disorder of abnormal pain sensation. This
condition presents in the first year of life with episodes of severe rectal pain following
bowel movements. This is often accompanied by reflex anoxic seizures (RAS). Finally
there is a colour change down one half of the body; either horizontally from the waist
down or involving one half of the body as in the harlequin phenomenon.