Excessive washing with harsh soaps and abrasive skin care products may be behind the rise in eczema and other allergic diseases, scientists have claimed.
The current thinking is that reduced exposure to infectious disease – particularly in childhood – weakens the immune system and allows allergic responses to emerge.
But researchers at the UCL Institute of Child Health/Great Ormond Street Hospital believe there may be another explanation.
Professor Robin Callard said: ‘Too much washing with strong soaps, using exfoliants and other such skin care products, and perhaps biological washing powders could be stripping away the skin’s outer protective layer resulting in allergic responses to allergens in susceptible individuals.’
Researchers found that if the outer protective layer of the skin is stripped away – which they did using something as simple as sticking tape – allergens and other proteins are able to penetrate the skin.
These are taken up by specialised cells called Langerhans cells and then move from the skin to the local lymph nodes and induce an allergic response.
Professor John Harper said: ‘It is important to stress we think it is over zealous washing using harsh detergents and/or abrasive skin care products that can damage the skin that are likely to be at fault and not normal washing or normal standards of cleanliness.
‘For example, we actively encourage our dermatitis patients to bathe frequently: that advice does not change. Good standards of hygiene are clearly important to prevent spreading of unpleasant diseases.’