# If we lost the ability to feel itchiness, would it matter? **URL:** \ **Category:** Factual Questions\ **Created:** [July 9, 2007, 6:34am UTC](https://boards.straightdope.com/t/if-we-lost-the-ability-to-feel-itchiness-would-it-matter/411026 "2007-07-09T06:34:22Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Leaper](https://avatars.discourse-cdn.com/v4/letter/l/4bbf92/32.png) [@Leaper](https://boards.straightdope.com/u/Leaper)\ **Post date:** [July 9, 2007, 6:34am UTC](https://boards.straightdope.com/t/if-we-lost-the-ability-to-feel-itchiness-would-it-matter/411026/1 "2007-07-09T06:34:22Z")
We know that not being able to feel pain is an incredibly serious problem, as evidenced by common sense and those few rare cases in the medical field. But as I put some ointment on some itches (which I actually asked about in another thread here, but I won’t get into that), I wondered: if there were rare cases of people who aren’t able to feel itchiness (but had otherwise perfectly functional skin/nervous system/etc.), would they be in serious trouble? Is there any reason why we NEED to feel itchy at times? (For the purposes of this question, and my own, possibly mistaken understanding, I’m assuming that the rare cases of being unable to feel pain is, in of itself, the serious problem, and not any accompanying brain malfuction or disorder that might’ve been the cause or result.) ---
**Author:** ![groman](https://avatars.discourse-cdn.com/v4/letter/g/73ab20/32.png) [@groman](https://boards.straightdope.com/u/groman)\ **Post date:** [July 9, 2007, 6:52am UTC](https://boards.straightdope.com/t/if-we-lost-the-ability-to-feel-itchiness-would-it-matter/411026/2 "2007-07-09T06:52:25Z")
[Link to a possibly relevant thread](http://boards.straightdope.com/sdmb/showthread.php?t=425574&highlight=scratching+evolution) ---
**Author:** ![psychonaut](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/psychonaut/32/4655_2.png) [@psychonaut](https://boards.straightdope.com/u/psychonaut)\ **Post date:** [July 9, 2007, 1:19pm UTC](https://boards.straightdope.com/t/if-we-lost-the-ability-to-feel-itchiness-would-it-matter/411026/3 "2007-07-09T13:19:32Z")
Itchiness is an early symptom and thus an important diagnostic criterion for various diseases, allergies, and drug interactions, some of them fatal, so yes, I would say that itchiness can be useful. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [July 9, 2007, 3:04pm UTC](https://boards.straightdope.com/t/if-we-lost-the-ability-to-feel-itchiness-would-it-matter/411026/4 "2007-07-09T15:04:58Z")
Itchiness can be a defense against external parasites. Ticks are a real problem in some places here in Panama. In some areas you can come back from a walk in the forest with dozens of juveniles about a millimeter across. I usually get most of them right away, but sometimes I will miss a few. I am alerted to their presence once they begin to itch after a day or two, and can remove them. ---
**Author:** ![Sattua](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sattua/32/11906_2.png) [@Sattua](https://boards.straightdope.com/u/Sattua)\ **Post date:** [July 9, 2007, 3:09pm UTC](https://boards.straightdope.com/t/if-we-lost-the-ability-to-feel-itchiness-would-it-matter/411026/5 "2007-07-09T15:09:52Z")
Pain and itch signals are carried by the same fibers. I don’t think you can take away one without taking away the other. So taking away itchiness would take away pain… and as the OP stated, that’s a big problem. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [July 9, 2007, 5:03pm UTC](https://boards.straightdope.com/t/if-we-lost-the-ability-to-feel-itchiness-would-it-matter/411026/6 "2007-07-09T17:03:02Z")
[QUOTE=Sattua] Pain and itch signals are carried by the same fibers. I don’t think you can take away one without taking away the other. So taking away itchiness would take away pain… and as the OP stated, that’s a big problem. [/QUOTE] This isn’t entirely true. While there is some overlap, pain and itch are not identical. From [here](http://telemedicine.org/anatomy/anatomy.htm) > [@](#): > > Tickle and itch: These sensations are experienced when mild stimulation of the pain nerve endings occurs; there are also specific free nerve endings for itch sensation; tickle and itch sensations are transmitted by group C unmyelinated nerve fibers; histamine produces itch while pain signals suppress it; tickle is itch produced by light external moving stimuli and is a pleasurable sensation; itch is an annoying sensation while pain is unpleasant; itch sensation excites the scratch reflex