Why do we get itchy when we scratch?

When the need to scratch disappears, it does not mean that the itching has stopped, but that the brain has stopped sending the alert signal.

You may not have realized it, but every day you scratch a few times in different areas of the body. Sliding the nails or an element where we have itching can be one of the most pleasant sensations that exist, but also the cause of greater irritation and infection.

In this article we will tell you why our skin itches, what are the reasons we scratch, how we enjoy relief from reducing itching and what can cause scratching too much. Do not miss it!

Why does our skin itch and what happens when we scratch?

We have about 2 square meters of skin, from head to toe. Every millimeter of dermis is exposed (to a greater or lesser extent) to different materials, microorganisms, textures, etc. In the same way that happens with the immune system within us, the skin has an effective team of defenses to prevent any threat.

Pruritus (medical term used for itching) is a warning that the body gives us so that we are alert to that agent that wants to enter or remain on our skinThere are various stimuli that can cause itching. The most common are:

  • Dust
  • Hair
  • Clothing
  • Insects

When these have contact with the dermis, the receptors located on the surface send a message from the spinal cord to the brain and that causes the sensation of itching.

In the event that the itching is mild, it is likely that we will scratch a little and relieve the itching. There are other reasons we scratch ourselves, from an allergic reaction to being nervous or upset.

Scratching is an automatic reaction that we cannot control. As it is an immediate response from our body to an external threat, we do not have the autonomy to stop this habit.

The brain sends a signal so that we can get rid of the agent that caused the irritation or danger. Finishing scratching does not mean that the cause of the itch has disappeared, but that the body no longer sends the alert signal to that area.

The problem is that, by passing the nails, fingers or a pen (to give an example of an element used) we can stimulate areas that were not previously compromised and spread the itching  and, also, cause an infection or greater irritation.

Why do we scratch more when we are nervous?

Stress has many negative consequences on our body. And not only internally, but also externally. When it comes to the skin, it is proven that stress makes us itchier. Or, rather, more desire to scratch.

This is because it activates the immune system and increases the signals sent to the brain through the nerve endings in the skin. Many stressed, worried, or pressured people have experienced excruciating itching that triggers dermatitis, eczema, and infections.

Stress increases the number of immune cells in the skin and activates them. That is why it is more likely to suffer certain imbalances, such as pimples or dryness, when we are very nervous.

Precisely the nervous allergy is another of the consequences of not being calm or relaxed. Emotions and thoughts can influence the number of times we scratch ourselves.

Some doctors indicate that we need to scratch certain areas of the skin as a solution to remove problems from the head. It is a way that human beings have to try to relieve stress (as can happen when we bite our nails, for example).

The more we scratch, the itchier we get

Associated with the sensation of itching is accompanied by relief. But that’s only for a few moments. The itch/scratch cycle could easily be related to the pain/pleasure or the action/reaction cycle.

The scientific investigations are moving forward on this issue and have identified nerve fibers that have the function to transmit the itching sensation to the brain areas which then send the signal we scratch hands to us.

Basically, this is trying to explain why some people scratch continuously and others don’t. Many think that the cause may be poor hygiene, but itching or the urge to scratch is caused by the messages that the brain sends and receives through the nerve endings.

That primary instinct that we cannot control sometimes becomes a disorder that does not allow us to do any other activity. Even while we sleep, we can dig our nails in order to remove an itch.

So… why the more we scratch the more it itches us?

This question has revealed the dream to many scientists, until a group of researchers from the Saint Louis University School of Medicine, in Washington DC (United States) has been able to answer this dilemma.

Apparently, the key is in the neurotransmitter called serotonin, which the body secretes when we rub anything against the skin in order to reduce itching. According to studies, this is responsible for the fact that we constantly scratch ourselves or that once an area begins to itch, we cannot stop fixing our attention on it.

Scratching relieves the itch, but creates pain. The body responds to this stimulus by releasing serotonin and therefore the sensation of itching increases. These discoveries serve to treat patients with chronic itching.

If the communication between serotonin and the nerve cells in the spinal cord (responsible for transmitting the sensation of itching from the skin to the brain) is blocked, people would not feel that urgent need to scratch continuously.

Although this cure used in the laboratory is not yet available, work continues to break that “vicious circle” of itching and scratching that bothers us so much or we would like to avoid.

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