Allergy sufferers have been told to use EpiPens past their normal expiry date, amid shortage of the life-saving devices.

It has been agreed that the use-by date of some EpiPens can be extended by four months according to the medicines regulator.

EpiPens are the most common adrenaline auto-injectors and are prescribed to people with potentially serious allergies, such as to nuts, milk, fish, shellfish, eggs and some fruits.

They can only be used once and usually have an expiry date that lasts for a minimum of 12 months.

There has been a shortage of EpiPens in the UK and other countries for months, as well as a lack of the alternatives - Jext and Emerade - due to a rise in demand.

Medicines and Healthcare Products Regulatory Agency said it had agreed to a request by the company behind EpiPen, to extend the expiry date of some batches of the 0.3mg version of the device.

It said the devices would work "just as effectively" during the extended expiry period. The extension does not apply to the 0.15mg version, given to children under 30kg.

Emma Cummings, whose 10-year-old son Loui has severe allergies, said if supply problems continued and she had no adrenaline auto injectors left that were in date, she would be forced to keep her son indoors, as he is at risk from airborne allergens.