If you scratch, then the sensation that provoked it is by definition an itch. At first glance, itch and pain seem to be related. The skin is studded with an array of nerve endings called nociceptors whose job is to relay information about the presence of potentially damaging stimuli to the spinal cord and brain.
A weak assault on those neurons results in an itch, while a fully fledged attack results in pain. Then there is the more chronic, pathological type of itch that could be associated with dry skin, eczema, psoriasis, or other skin diseases. Brain tumours, multiple sclerosis, chronic liver disease, lymphoma, Aids, and hyperthyroidism have all been associated with chronic itch, as have diseased neurons. Then there are the psychological and cognitive factors, but not all are as creepy as delusory parasitosis.
An obsessive need to scratch can be a manifestation of obsessive-compulsive disorder; in these cases, persistent scratching can damage the skin and only serves to exacerbate the problem. The pain from a scratch is very different from one we might feel when we put a finger in a naked flame Credit: iStock.
That the itch sensation can be reduced by the application of painful stimuli only makes it an even more curious phenomenon. Scratching is a relatively minor form of pain, but the light pain we experience raking our nails across our skin does seem to help, as does the application of cold, or heat, capsaicin the chemical that gives peppers their heat , or even a few electrical zaps. This means, paradoxically, that analgesics, which are meant to reduce pain, can actually enhance itch.
When something hurts, our body responds with its withdrawal reflex. So, when our ancestors in the paleolithic age noticed their companions scratching themselves, it would have made sense for them to do the same, in order to rid themselves of whatever insects or parasites appeared to be bothering their fellow human beings. Researchers are beginning to focus more on this area of inquiry.
She is a lawyer by education, a poet by accident, and a painter by shaukh. You can find her on Instagram devruparakshit. Follow us. Newsletter Exclusive news delivered to your inbox.
Scratching My Head. Oct 2, Share. Image Credit: iStock. Tags Scratching My Head serotonin. See all articles by Devrupa. While the initial mood boost feels great, it also ironically leads to more itchiness, says Dr. Basically, serotonin betrays you by leaping over from pain-sensing nerve cells to those that raise the intensity of your itch. A simple fix: Stop the itch at the source by finishing off your back scratch with a moisturizing cream , ideally one that contains hydrating ingredients like jojoba oil, dimethicone, glycerin, or shea butter, per the American Academy of Dermatology Association AAD.
Your skin barrier will thank you, and you still get the good feeling from scratching the itch. United States. Type keyword s to search. Sign up for our email newsletter. Sign Up. Support science journalism. Knowledge awaits. See Subscription Options Already a subscriber? Create Account See Subscription Options. Continue reading with a Scientific American subscription.
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