Why Scabs Itch and Why You Shouldn’t Scratch Them
Medically reviewed by Jane Kim, MD
The exact reason why scabs itch isn't completely clear, but scientists have a few theories. When you get a cut or scrape, your body releases chemicals called histamines, which may cause irritation and itching. And as the wound heals, the action of new cell formation can be interpreted by the brain as an itching sensation.
An itchy scab can be irritating, but it’s typically a sign that a wound is healing correctly.
Verywell / Sydney Saporito
How Wounds Heal
When you injure yourself and cut, scrape, or burn your skin, blood begins to clot in order to stop the blood from excessively leaving your body. Blood clotting happens thanks to cells called platelets. Forming platelets is the body’s way to patch up a leak.
Eventually, when the wound stops bleeding, a scab forms. The scab helps protect the freshly injured skin from contaminants like bacteria and allows the skin to heal.
Underneath a scab, your body is working hard to repair damage to the skin and blood vessels. The body also enlists white blood cells to help clean up any foreign matter and bacteria in the wound. After some time, a scab will fall off to reveal brand-new skin. It’s a pretty amazing process.
Of course, the body can’t repair all wounds this way. Deep wounds and severe burns require emergency medical treatment. But most small nicks, cuts, scrapes, and surface burns heal well on their own in a healthy person.
Related: What Scabs Are and How They Heal
Why Scabs Itch
Itching occurs as a normal part of healing. However, the reason the itch develops isn't completely understood.
One study from 2016 suggests that the same mechanisms at work with eczema itchiness are involved in itching during wound healing.
While some experts believe histamines, which are released by the body to help with wound healing, may contribute to itching, research suggests that their effect may be minimal.
Itching may also be triggered by certain inflammatory mediators, such as cytokines and nerve growth factor, that interact with receptors on sensory nerve fibers. Fibroblasts, which play an important role in tissue growth and repair, have also been linked to itch.
When to See a Healthcare Provider
It’s time to see a practitioner if you have symptoms of an infection. Signs that a wound may be infected include:
Redness and swelling
A red streak that’s emanating from the wound
Severe pain
Swollen lymph nodes
Fever
Black edges around the wound, which may be necrotic tissue
An injury that isn’t healing or whose stitching has opened up
If you don’t have an up-to-date tetanus shot, you should see a healthcare provider immediately, especially if the wound has dirt in it.
Why You Shouldn’t Scratch
Scratching an itch feels great. It’s so satisfying, in fact, that people tend to scratch even when they really shouldn’t. Scratching an itchy wound that is in the process of healing, however, can cause scarring and prolong healing if you open the wound back up again.
You might even introduce bacteria, causing an infection to develop.
Wound Healing Tips
When you get a minor cut, scrape, or burn, it’s essential to properly take care of the wound. Proper care ensures the wound heals without complications and lessens your chances of getting a scar. For a minor wound:
Clean the area with gentle soap and water to remove debris and bacteria
Bandage the area to prevent contamination
Avoid scratching during the healing process
If your wound is deep, very large, or doesn’t seem to be healing, see a healthcare provider. Some wounds require stitches. An injury that’s infected may require antibiotic treatment.
How to Stop Itching
Itching can sometimes be excruciating, even more so if you’re trying not to scratch. However, it’s important to avoid excessive scratching because it can cause the wound to open up again. By alleviating the itch, you can avoid a prolonged healing process and potential infection from scratching too much. Here are a few ways to stop the itching:
Applying cold or warm compresses
Moisturizing
Avoiding tight clothing or accessories worn around the wound
Covering the wound with a bandage
Applying over-the-counter (OTC) anti-itch creams
Bathing in lukewarm water with added moisturizers or oatmeal
It may also help to find effective distractions from the itching. If itching is due to a more significant or more chronic injury, then your healthcare provider may prescribe gabapentin or other medications to provide relief.
Who Is at Risk for Slow Wound Healing?
Some people are at a higher risk of experiencing slow wound healing, which can lead to infection. The following people have a higher risk of complications from a wound:
People with diabetes
Older adults
People on certain medications
Smokers
People who drink heavy amounts of alcohol
People with poor blood flow
If you tend to scratch in your sleep, you may want to wear hand coverings. They can prevent you from damaging your skin or introducing bacteria to the wound. It may also help to cut your fingernails.
Frequently Asked Questions
What's inside a scab?
Inside a scab are platelets, white blood cells, other various blood cells, and fibrin (a protein that helps stop blood flow). Platelets clump together to form a clot, while white blood cells attack any bacteria inside the wound that can cause infection. Removing a scab during this healing process can undo the repairs it has undergone and force it to start from scratch.
Why do stitches itch?
Stitches can itch for the same reason that small cuts or scrapes itch - the wound is in the process of healing. The length of time that itchiness lasts can vary, but it may persist until the stitches are removed or fade away. Scratching the itch is tempting, but it's important to avoid picking at it so that it properly heals.
Why does scratching an itch make it worse?
Scratching an itch may make it worse. According to research in mice, serotonin may have a role in itch. This neurotransmitter is produced in the brain and released to help regulate mood and pain perception. Scratching an itch may cause pain and the release of serotonin. While it may offer brief satisfaction, serotonin does not prevent the itch from returning and may actually intensify it.
Read the original article on Verywell Health.
