People with severe allergies have to carry an Epipen in case of emergency
Better access to NHS allergy services is needed for people who have suffered an anaphylactic reaction, the Royal College of Physicians warns.
The number of people hospitalised for anaphylaxis caused by triggers such as peanut allergies or insect stings has risen dramatically in the past decade.
All patients should be referred to a specialist allergy clinic, guidelines from the the College recommend.
Charities agreed there are too few allergy services to cope with demand.
Around a third of the population will suffer allergies at some point, although only a minority of these will be severe allergies.
Anaphylaxis is a severe, life-threatening reaction during which people can suffer a rash and swelling, breathing problems, increased heart rate, and loss of consciousness.
In 1997/98, 551 people were admitted to hospital after an anaphylaxis due to an adverse food reaction, but by 2007/08 this had risen to 1,104.
Likewise, the number of anaphylactic reactions for unspecified reasons rose from 706 to 1,777.
The latest RCP recommendations are based on advice from the Resuscitation Council. They state that all healthcare professionals need to be able to quickly spot signs of anaphylaxis to provide early treatment and avoid serious consequences.
The guidelines also urge the quick use of an adrenaline injection into the muscle in those affected.
After discharge all patients must be given a follow-up plan and be referred to a specialist allergy clinic to identify the cause and reduce the risk of future reactions, the guide states.
THE NEED FOR SPECIALIST CARE
Hannah Elliott developed a severe fish allergy when she was 18 and has since had allergic reactions to several medicines including antibiotics.
Fortunately, for Hannah, she is being treated at a specialist allergy unit in London.
She now carries two adrenaline injector pens with her at all times and has received advice on how to manage her condition.
"Everyone needs antibiotics at some point in life and I need to be aware of which ones I can take that are non life-threatening.
"They have also taken bloods to test all fish types and other foods which I might be allergic to."
Lynne Regent, chief executive of The Anaphylaxis Campaign, said better education of clinicians was welcome but there was still a shortage of allergy services for patients to be referred to.
"There are not enough allergy specialists or specialist centres.
"People who have experienced anaphylaxis are at high risk of further severe reactions, and this places a tremendous burden of anxiety on them.
"It is extremely important that they have confidence in the help they receive from medical professionals."
Dr Jasmeet Soar, co-chair of the Royal College of Physicians Working Group on Anaphylaxis and vice chair of the Resuscitation Council (UK) said the diagnosis and treatment of anaphylaxis can cause confusion for clinicians.
"Someone who has this sort of reaction needs confirmation it's an allergic reaction, then we need to find out what caused it and how to avoid it the next time so they need to be properly followed up by a specialist."
Muriel Simmons, chief executive of Allergy UK said they receive very anxious calls from people who have suffered an anaphylactic reaction.
"Generally they have been well treated by A&E but they have then been discharged without any support or advice on how to get the specialist help they need for a proper diagnosis on the trigger for their reaction.
"The guidelines are a good step forward and if the guidelines are used it will improve the current position."
She added that the onus for specialist referral should be on the hospital treating the patient rather than leaving follow-up to the GP.