Why do we feel itchy?
Itching is a sensation that we have all experienced throughout our lives, although it often goes almost unnoticed: we scratch without realizing and, at some point, it disappears.
The problem occurs when the itching sensation does not decrease or even intensifies when scratching. In this case, it could be associated with some pathology or be a wake-up call from our skin indicating that something is wrong.
If you continue reading this article, you will discover:
- Why does the itching sensation occur?
- How to relieve itching
Origin of itching
Until recently, itching was thought to be a sensation like pain, but much milder, an annoyance that we could not identify as painful.
In 2007, at the University of Washington, Zhou-Feng Chen’s team discovered that there were specific neurons, different from those of pain, which are responsible for propagating the itching sensation until it reaches the brain, where the signal is interpreted, and a response is generated: scratch.
One of the molecules that leads this process is the TRPV1 receptor, which is found both in skin cells and in nerve endings. When TRPV1 detects certain stimuli, such as variations in temperature, pH, or molecules such as the capsaicin present in jalapeños, it activates and starts the signaling cascade that allows our brain to identify itching. In this way, we interpret that something is not going well in that area of the skin, and we try to solve it, sometimes unconsciously, by scratching ourselves. Then we stimulate other types of nerve fibers, “deactivating” those of itching and causing their signal not to reach the central nervous system.
Scratching can be very pleasant at first, but when itching becomes chronic, it can have a negative impact on quality of life.
Causes of itching
The stimuli that trigger itching can be very different, from an insect bite to the sensation we experience before getting sunburned or when we have extremely dry skin areas.
In the case of the insect, it is itself that, while biting us, injects certain substances capable of triggering the response. On the other hand, when we have dry skin, whether due to sun exposure, some pathology, medication, or any other external factor such as wind, cold or the use of certain chemical products, itching appears because of a lack of protection on our skin.
In previous articles we talked about the importance of taking care of our skin as a protective barrier, but when the hydrolipidic film that protects it suffers some type of aggression, it stops carrying out its function correctly and a vicious circle begins in which the skin is exposed to any type of external aggression, thus disturbing the nerve endings.
How to avoid or relieve itching when it appears
Prevention is better than cure. For this reason, we should anticipate itching as much as possible, continuously nourishing and moisturizing our skin well, thus having a healthy skin barrier that receives the least possible number of aggressions.
However, there are certain factors that are difficult to control: an insect bite, the need to take a medication that affects the skin or suffering from a condition such as atopic dermatitis. In these cases, scratching can make symptoms worse. For this reason, it is important to use products that calm itching so as not to aggravate the loss of skin protection.
At Prospera Biotech we develop neurodermatologic products specifically designed to keep the neurosensory system balanced and help improve the most sensitive areas affected by itching. Do you want to meet them?
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Garibyan L, Rheingold CG, Lerner EA. Understanding the pathophysiology of itch. Dermatol. Ther, Mar-Apr 2013; 26(2).
Cevikbas F, Lerner EA. Physiology and Pathophysiology of itch. Physiol. Rev, Jul 2020; 100(3):945-982.
Jeffry J, Kim S, Chen ZF. Itch Signaling in the Nervous System. American Physiological Society Journal, Aug 2011.