The survey by the Food Standards Agency and Allergy UK also found that nearly one in five (19%) of those allergic reactions resulted in a hospital visit.

The EU Food Information for Consumers (FIC) legislation came into force in December 2014, and means that food businesses have to make information on 14 allergens available to consumers, including peanuts, gluten and less known triggers such as mustard and celery.

Dr Chun-Han Chan, food allergy expert at the FSA, said: 'It’s been more than a year since the introduction of this legislation and we’re pleased to see real progress in how food businesses provide information on allergens to their customers. In general, the situation is improving for the two million food allergic consumers in the UK, and greater numbers have the confidence to eat out.

“However, our survey has found that this isn’t true for everyone, and that many establishments aren’t yet providing the information that their customers need. The number of people suffering from food allergies and intolerances has increased in the last decade, so it’s clear that it is not something businesses can ignore. Allergies can be fatal, and this is why it is vital food businesses give their customers information they can trust.”

The survey, which was carried out to mark Allergy Awareness Week 2016, found that overall 83% of respondents reported noticing an increase in measures designed to make life easier for allergic consumers  – including menus marking out allergens, and staff actively checking food information with the kitchen.

More than half (58%) of allergic consumers said that their overall experience of eating out has improved; just 6% said it has got worse. As a result, a similar proportion (52%) say they now feel more confident eating out than they did before the legislation was introduced.

However, people with allergies still report a number of problems when eating out. More than two-thirds (69%) have experienced staff not understanding the severity of an allergy, and how easily a mistake can cause a reaction.

A similar number (68%) have seen staff with a lack of knowledge of what’s on the menu or in the food – including staff confusing eggs with dairy, or assuming that the customer was asking for gluten-free rather than avoiding lupin (a grain commonly used in place of wheat). Over half of allergic consumers (56%) said they have been made to feel like an inconvenience due to their allergy.

In total, around a third of those with a food allergy have suffered a reaction in the last year when eating out of the home. The vast majority of these (25%) took place in a restaurant or cafe, with 9% being a result of takeaway food. In most cases (88%) the reaction was self-treated, with 19% of reactions resulting in a hospital visit.