Insect Bites and the Itch

The saliva of biting insects contains an anticoagulant so that they can suck up your blood without it congealing in their mouths. It is this saliva that causes the itch.

Ok!! But at times nothing bites and still there's some skin irritation and you feel like scratching. Why's that?

Hello elika

As well as the two search lists in a previous post of mine, I post this piece which explains it in a quite short way. I hope it answers your questions MadSci Network: Medicine

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Query:

Re: What causes an itch, and why does scratching eliminate it? Area: Medicine Posted By: Robert West, Post-doc/Fellow Date: Mon Mar 3 16:18:30 1997 Message ID: 854921414.Me

What is Itch?

Doctors and scientists have been studying itch for a long time, but there still is no completely satisfactory answer to the question of what is itch. Itch can be caused by a wide variety of physical and chemical stimuli, such as light pressure, warming, exposure to acids or bases, or histamine release (allergic reactions). As a practical matter, a major factor in itching is damaged skin. Dryness, either from outdoor exposure or dry heated air, and contact with detergents or hot water can break down the protective barrier that skin provides and allow nerve endings in the skin surface to become irritated. Because itch can be elicited in so many ways, scientists have constructed a fairly detailed classification system. In general though, itch can be divided into 2 categories, sensory itch and allergic itch. Sensory itch is distinguished from allergic itch by the lack of external skin rash or irritation at the itch site.

Very early experiments on cutaneous sensation ignored the phenomenon of itch. Later experiments showed that the body was covered by "itch spots", small spots of the skin about 1mm apart which convey a sensation of itch when lightly touched. However, any part of the skin can become itchy if exposed to the correct stimulus. One extremely important bit of information is that a spot that is itchy usually doesn't have pain sensitivity. Itch is not merely a "subliminal" sort of pain. This is well demonstrated by the observation that opioids, such as morphine, are quite good at blocking even severe pain, but also produce itchy skin as a side effect.

Researchers have put together a fairly detailed description of the physical aspects of itch, but the physiological mechanism behind itch remains elusive. It is known that itch can only be evoked from superficial layers of skin, mucous membranes or conjunctiva. Therefore, only certain populations of nerves carry itch signals. We know that humans can feel itch when large diameter myelinated (insulated) nerve fibers are blocked , which means that itch is transmitted to the spinal cord and brain through smaller, thinly insulated or uninsulated fibers. This in turn means that sensory endings which are excited by weak mechanical stimulation ( Merkel's discs, Meissner corpuscles, Pacinian corpuscles, etc...) do not transmit the itch sensation. More likely itch is transmitted by lightly insulated or uninsulated nocioceptors (pain receptors) in the superficial skin. Recordings of the activity of these types of neurons have shown that they respond well to many of the stimuli that cause itch.

Why does scratching an itch make it go away?

It turns out that mild scratching is one of the best ways to excite the pain neurons with uninsulated axons. There are several competing theories regarding why this relieves itch. Essentially, scientists believe that the massive signal that mild scratching sends to certain populations of pain neurons temporarily overwhelms or masks the itch sensation.

The information in this response was primarily derived from "Itching for an Explanation" by S.B. McMahon and M. Koltzenburg, Trends in Neuroscience, Vol 15, No. 12, 497-501, 1992. If you have any questions or comments, please send me an email.

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Hello NOJ,

I do not know if it is the 'whole' answer, but your post is a good one!

GA to you Sir.

Ask Del.

Just an extra to this my wife bought a no itch remedy for insect bites, it is about the size of a disposable cigarette lighter. You push the base onto the bite and push a button on the top this generates a small electrical charge at the base that stops the sting or bite from itching. It works instantaneously.

I haven't heard of this. Can you please give us more details?

Hello Grotchy,

Can you send details of this. Like the name and make of this product please?

it must inflict something of a mild sting, I'd suppose..?

for itch that's localized, and can be identified to a spot on the skin, I "fence in" the itchy spot by creating an impression around it with my fingernail edge. I press hard with the fingernail's edge, forming a rough square around the itchy spot. instant gratification!

Another "cure" for insect bites which I'm astonished is not better known is to hold something hot (cup of tea or coffee) against the bite for as long as you can bear.

I usually burn myself with a cigarette lighter for this purpose, not that I actually smoke.

I thought that it was just me.

I have used a soldering iron in the past for this exact purpose...then take an Advil for the pain.

With solder and flux?

Boric Acid works the best!

"Life is all about humor...it always comes down to volume control".

on any body part?

some parts gotta hurt more than the others...

Helo Nic,

Boric acid eh? ...........Mmmm.

No really sure how to answer but to tell the truth. I have little volume and certainly no control of the "useful bits", lets say! Maybe I will give the boric acid a miss for today? Thanks all the same.

"Life is all about humor...it always comes down to volume control".

Take care................

regards

Techs mostly try ....

Have you also ????

Regards.

There are different treatments in the world.

In Bangladesh-Bharat-Pakistan region we used locks [Iron] to rub the area & it relieved a lot.

& there are more ... all work well. How? but these work.

Regards.

Have you ever tried an ice-cube? It also relieves.

Hello Randall,

Another "cure" for insect bites which I'm astonished is not better known is to hold something hot (cup of tea or coffee) against the bite for as long as you can bear.

=

This probably works by the heat attracting extra blood, which brings our bodies Natural 'antibodies' to fight any potential 'invaders', and in doing so relieves any pain or sting.

It may well act to swell the skin and flesh locally to put pressure on any poison or, local irritant which might have been injected, thus squeezing it out of the entrance hole the 'bite' or 'fang' made.

Regards.

May be ...

Off topic really but a few drops of Lavender oil massaged onto any exposed skin keeps most nasty biting insects at bay...it has worked for me in both Colorado while fishing and in the Scottish highlands (midges)....

I am sure that some insects somewhere are not put off by it and I would be most interested to hear of any experiences in this area....

By the way, its not sun tan oil (too expensive for that!), just the "suggestion" of it is more than enough......a 10CC bottle (tiny) lasts me a season......

As someone else mentioned, warmth and or Antihistamine helps if you do get bitten....

Hello elika,

You and others posting here may be interested in some of the 'remedies' I found on this search:=

http://www.google.com/search?client=safari&rls=en-gb&q=stopping+an+itch+from+a+biting+insect&ie=UTF-8&oe=UTF-8

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Look near the bottom of the first page and you will see 'heat' is said to help the itch.

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The link below explains why skin itches:

http://www.google.com/search?client=safari&rls=en-gb&q=why+does+skin+itch&ie=UTF-8&oe=UTF-8

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This is really interesting as a Family member has eczema.

This may be a bit off topic, but I was introduced to a new insect repellant technique this summer. Listerine mouth wash sprayed on the people and the chairs. It seemed to last long enough to have an evening meal with no mosquitoes. There were some flies, but they seemed less also. Has anyone else heard of this?

Hello bob c

Never heard of that before. But anything is worth a try, right?

Take care..............