The armpit (axilla, axi = axis/Greek) is one of the skin areas with special physiological properties: The high number of sweat glands (i), occlusion and increased perspiration make the pH (i) of the armpit at 6.5 decidedly higher than the normal physiological value of 5.5. Because of this, a gap in the protective acid mantle (i) develops.
In this special environment, certain bacteria populate and thrive on the skin. They produce strong-smelling substances (i) through metabolisation of sebum and sweat, which has a very hard time evaporating due to the occlusive effect of the armpit.
The principle of action of deodorants
Deodorants should effectively prevent body odour and its development. To accomplish this, various action principles and combinations of ingredients are used:
- Bactericidal substances (antiseptics) and the creation of an acidic pH (i) prevent growth of odour-producing bacteria.
- Antiperspirants reduce perspiration.
- Certain active ingredients bind the odour-producing substances.
- Fragrances mask the body's odours.
Deodorants and skin compatibility (i)
Apart from the effectiveness of the deodorant, skin compatibility (i) is a deciding factor. This is especially important for people with sensitive skin, a deodorant intolerance, psoriasis or atopic dermatitis, because sensitive and already damaged skin is prone to develop contact dermatitis due to the impaired barrier function. The presence of penetration-promoting additives such as alcohols greatly enhances this effect. Therefore, it is prudent to dispense with the use of alcohols and fragrances in medical deodorants.