Those suffering "life-threatening" allergies have been told to take action and replace a certain brand of adrenaline pens amid serious faults.

The Emerade 300 and 500 microgram auto-injector pens, which are used to treat anaphylaxis, have been recalled by regulators.

These pens are prescribed to those with life-threatening allergies. However, the Medicines and Healthcare products Regulatory Agency (MHRA) have called on users to swap the brand for another.

Other brands include Epidpen and Jext with patients also being advised to seek help on how to use these as well.

Patients have been told to return their Emerade pens only once they have been given a replacement as a recall is issued.

Current estimates state that around 25,000 people may have one in need of replacement.

Similar concerns have been raised about Emerade products in the past.

Dr Alison Cave, MHRA chief safety officer, said: "Patient safety is our top priority. We are taking prompt action to protect patients, following detection of damage to internal components of the Emerade pens if they are dropped, which may mean they activate too early or fail to activate and deliver adrenaline.

"Patients are reminded to carry two pens with them at all times as normal and to contact their healthcare professional when a replacement is due."

What are the main causes of anaphylaxis?

The most widely reported triggers for anaphylaxis are, according to the NHS, insect bites (usually wasps or bees), peanuts and tree nuts, food such as milk or seafood and medicines like antibiotics.

What are the symptoms of anaphylaxis?

The NHS also lists lightheadedness, breathing difficulties, wheezing, fast heartbeats, clammy skin, anxiety and collapsing or loss of consciousness as potential symptoms of anaphylaxis.