Bioderma Ireland | Itching: Understand better with our experts

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Itching: Understand better with our experts

Itching: Understand better with our experts
Dr Isabelle BARATTE

A SYMPTOM THAT EXPLAINS EVERYTHING
Dr Isabelle Baratte,

Dermatologist,
Attached to the Civic Hospices of Lyon

What is the itching importance during a consult?

 « It is a very recurrent symptom, that we experience at any age during life. During a consult, we meet as many as babies with eczema than elderly persons with a very itchy dry skin. Itchings may be temporary or permanent, sometimes restricted or affecting all the body. This symptom, a bit global, correspond to very different situations and the stake is to understand what is the cause of it.» 

What are the consequences of itching?
Itchings have an impact on the quality of life, specifically when these are intense and become chronic, beyond 6 weeks. We often observe sleep troubles, in particular for young babies and kids with eczema flare-ups. Babies' itchings have a direct impact on the family's life, that's obvious. For adults, the discomfort also affects the daily activities, with mood disorders, sometimes anxiety and depression, a global lack of well-being sensation. The expression « feel ill at ease with yourself » makes sense! Of course, that's important to soothe the itching sensation, but to take care of it and long-lastingly eliminate it, we need to find the origin.»
Isabelle BENOIT

Different causes at any age
Isabelle BENOIT

BIODERMA Scientific Director

 The pruritus designates the itching sensation. Some itchings have medical causes well identified. These are the main ones… »
ATOPIC DERMATITIS

This chronical inflammatory dermatitis alternates by flare-ups periods and calm. The cutaneous barrier, with recurrent lack of filaggrin, causes a severe skin dryness associated with excessive immune reactions.

CONTACT ECZEMA

It is a reaction caused by allergen contact with the skin. Jewellery, clothes, cosmetics or medicine make the skin sensitive and prone to itchings.

URTICARIA

It is characterised by red plates very itchy linked to a direct allergen contact with the skin, an immune answer with food, or an insect bite.

PSORIASIS

This chronical inflammation often has a genetic origin which affects 2% of the population. It is characterised by an increase of the epidermis cells proliferation and occurs by scale lesions.

SENILE XEROSIS

For people aged more than 65 years old, the lack of lipids may cause an itching sensation and discomfort.
That's Senile Xerosis, also called Senile Pruritus. It affects 60% of elderly persons.

« Many external factors may provoke itching such as heat, pollution or hygiene products. Pruritus is also strengthened during winter, due to the cold, heating, temperature changes which worsen the skin dryness. Even the water of the shower or bath may be sufficient to start itching; it is the aquagenic pruritus..»
Isabelle BENOIT

IT'S IN THE HEAD…
BUT NOT ONLY!
Dr Michèle SAYAG,

Allergist doctor

While the itching reflex is commanded by the brain, itching-scratching process, called pruritus by doctors, born within the skin. Understand how is necessary to find an efficient solution.
Michèle Sayag explications, Allergist Doctor.
One symptom but different mechanisms
which we call « pruritic paths »
Itchings begin at the sensory receptors of the epidermis, which are activated by different mediators, variables depending on the causes. The signal emitted along the sensory nerve endings to the brain, which triggers the scratch reflex.

• The pruritic pathways of urticaria and contact eczema go through the immune cells: they release mediators (histamine, substance P, serotonin, some proteases et cytokines), which activate the nerve fibres. Antihistamines stop or reduce itching by blocking histamine receptors but they are ineffective on other types of itching.
Apart from the well-known role of histamine in pruritus during urticaria, scientists have pointed out the existence of 2 news pruritic pathways, involving specific neurotransmitters, on which it is interesting to act to reduce the sensory nerve fibres activation that transmits the pruritus signal to the brain.

In Atopic Dermatitis, the pruritic pathway involves keratinocytes, superficial cells of the skin that release TSLP, which itself activates the sensory nerve fibres.
In Psoriasis, it is the NGF produced by keratinocytes that activates these same fibres.

• The mechanism is different in the cutaneous dryness due to skin ageing (or Senile Xerosis). The sensory nerve fibres activation necessarily occurs, but the pruritic path remains poorly understood. Most likely, it involves the alteration of the cutaneous barrier, specific to the skin ageing.
An anti-itching care must take into account the maximum of pruritic pathways. Thanks to its various active ingredients, Atoderm SOS Spray soothes itching of very different origins