Excessive washing with harsh soaps and abrasive skin care products is being blamed for a rise in allergic diseases such as eczema.
The "hygiene hypothesis" pins the rise on people being too clean, resulting in the immune system becoming too sensitive to infection.
But University College London's Institute of Child Health believe there could be a more direct cause.
They believe over-use of harsh products strips away a protective layer of skin.
This, they write in the journal Trends in Immunology, could make people more vulnerable to an allergic disease.
Rates of eczema and other allergic diseases are rising across the developed world.
Researcher Professor Robin Callard said many strong soaps, exfoliant beauty products and biological washing powders were all potent enough to strip away the skin's protective outer layer.
His research has shown that this protective layer is weakened in people with a rare genetic skin disease who develop eczema or other allergies.
Source - BBC