Itching

 We usually think of itching as a skin thing, maybe caused by an insect bite or some other kind of irritant or condition. But itching can be an indicator of something far more serious. I recently read about a woman who suffered from a terrible itchiness under her skin that never went away. Nothing helped. She spent a year visiting doctors, none of whom could solve her problem until one of them finally figured it out: she had Hodgkin lymphoma, a cancer of white blood cells. After treatment, her itching went away.

 Plenty of non-skin conditions can cause itching, including hyperthyroidism, iron deficiency, liver disease, and other cancers. Persistent outer-arm itching that worsens in sunlight is caused by a crimped nerve in the neck. Intense, diffuse itching upon getting out of a bath or shower is a symptom of a rare condition in which the body produces too many red blood cells.

 

Our bodies are studded with receptors for itch, and our itch sensations are exquisitely tuned. A single itch nerve fiber can pick up an itchy sensation more than three inches away. These fibers have been traced to the spinal cord and all the way to the brain, where specific areas light up in response itch activity.

 

Some people suffer from chronic itch—itch that last more than six months. Chronic itch is often a brain malfunction: “sensors” in the brain go haywire and start misfiring, making people perceive an itchy condition. As such, it’s a difficult condition to cure. You can easily become aware of the brain’s role in itching just by thinking about it. Sorry. Now you’ve probably got an itch.

For an introduction to this blog, see I Just Say No; for a list of blog topics, click the Topics tab.