A patch, which so far has been tested on mice, containing a manufactured version of the harmful proteins found in dust mite droppings might hold the key easing asthma in sufferers.

House dust mites are generally less than half a millimetre long and whitish in colour are said to be the leading trigger for asthma attacks.  Dust mites feed on dead human skin cells so can be found in pillows, mattresses, bed linen, clothing, carpets and soft toys.

The patch which can be worn on the arm or stomach, releases tiny amounts of the protein into the skin and is designed to train the immune system not to over-react when it comes into contact with dust mite droppings. Although it can take several months for the body to re-train the sufferer can stop wearing the patches afterwards.