Itchy Skin: Appearance And Causes
Without realizing it, we find that our nails are busy scratching different parts of the body. As you read these lines, you may do the same. Itching is not necessarily caused by a skin condition, and scratching is a normal reaction of the body.
What causes itchy skin?
Man has, on average, two square meters of skin, this being the largest organ of the body. This surface is directly exposed to many external agents. But, like other parts of the body, the skin has its own mechanism to prevent disease and protect itself from anything that is perceived as a threat.
The “normal” itching sensation is called pruritus and is only an alarm signal transmitted by the human body.
What are the factors that can affect the skin? There is a whole list that includes dust from the atmosphere, rubbing clothes or hair, certain insects, sweat, the scent of flowers or leaves, etc.
All substances or materials that touch the skin stimulate certain receptors that send an alarm signal to the brain, and it responds with a sensation: itching.
Itchy skin is relieved when we scratch, but the problem can be aggravated if we have dirty nails or fingers or if we put too much pressure on the skin. If the itching is more severe or is accompanied by pain, it may be the result of an allergic reaction.
Another reason why we frequently scratch ourselves is related to the emotional side, being a gesture characteristic of states of nervousness, anxiety, stress or worry.
Itchy skin: main causes
- Dehydration
- Dermatitis
- Psoriasis
- rosacea
- Heavy sweating
- Lack of hygiene
- Skin irritations
- Allergies
- Use of strong chemicals
- Insect bites
- Ticks or other microorganisms
- Stress
- Nervousness
- Anxiety
- Side effects of certain medications
- Low temperatures
Numerous studies have shown that there are certain neurons in the brain that perform this specific task: to indicate when the skin came in contact with something that could cause problems.
In 2007, a team of researchers from the University of Washington (USA) discovered that there are nerve cells in the body that are dedicated exclusively to the management of itching. The research was conducted by a biologist, a psychiatrist and an anesthetist, and the results were published in the journal Science.
The stimulus produced by the itching is taken up by the nerve fibers located under the skin. They send a signal to the brain through the spinal cord. At this point, the neurons make us aware that there is a factor that causes itching. These nerve endings are also responsible for alerting to the sensation of pain.
To scratch or not to scratch is the question
When we scratch, we respond to the stimulus that warns us that something is wrong. This signal informs us that there is a factor that causes skin irritation.
Therefore, when we scratch, we offer a feeling of relief by removing the “offensive” agent. And when the body goes out of alert, it no longer transmits the itching signal.
Also, scratching distracts us from itching. However, we end up stimulating a larger area of the skin than the one affected by pruritus, which leads to the extension of the threatening agent and implicitly of the itching.
Scratching is the response to a stimulus that we cannot control, such as coughing or sneezing. It is advisable to try to eliminate or avoid the factors that cause itching.
In another research project at Wake Forest University in Winston / Salem, Oregon (USA), magnetic resonance imaging was used to analyze brain activity during scratching. Participants were asked to scratch with a brush for 30 seconds, then take a 30-second break.
To their surprise, the researchers found that those areas of the brain associated with unpleasant emotions and memories were “disabled” while study participants were scratching. Maybe that’s why we feel a sense of relief and a sense of calm when we scratch.
Why are itchy skin more pronounced in winter?
Many people experience severe itching in the cold season. This is due to the fact that low temperatures, wind and snow dry the skin. The effects are more visible on the face and hands, as these are the areas most exposed to the cold.
Another reason may be the tendency to use more hot water than in summer. The change in temperature dries the skin even harder, which can cause dermatitis, especially if we use soaps and chemical detergents.
In addition, in winter we have to wear thicker and thicker clothes, which prevents the skin from breathing and causes itching. This sensation is also caused by woolen clothes or those cut with a very thick thread.
An effective way to prevent scratching and thus damage the skin is to apply compresses with a little ice on the itchy areas. You can also use a cloth soaked in chamomile tea or apply green clay in the form of a mask. Don’t forget the wonderful effects of the aloe vera plant on the skin.
