The number of children admitted to a hospital in England with a severe allergic reaction has increased every year for the past five years.
NHS data show that 1,746 children were treated for anaphylactic shock in 2018-19, up from 1,015 in 2013-14.
The parents of Natasha Ednan-Laperows, who died in 2016 after eating a baguette containing sesame, called the increase "deeply troubling."
Scientists say environmental factors may be to blame for more allergies.
When adults also included severe allergic reactions treated in hospital, the numbers increased from 4,107 cases to 5,497 in five years.
Children under the age of 10 are most likely to be affected by anaphylaxis, with 1,018 being admitted to the hospital last year – compared to 601 in 2013-14.
Anaphylaxis is a severe allergic reaction that can be life-threatening.
The most common causes of severe allergic reactions are foods such as nuts, fish and mussels, but they can also be caused by wasps and bee stings, medicines and dairy products.
Even the smallest exposure to one of these allergens may be sufficient to initiate an anaphylactic reaction and lead to difficulty breathing, rapid pulse and loss of consciousness.
It is not believed that the increase in allergies is simply due to the fact that the public will become more aware of them and better diagnose them.
Instead, scientists believe that factors such as dietary changes, germ exposure, and pollution can play a role in the upswing – especially for the Western lifestyle.
Natasha's mother, Tanya Ednan-Laperows, says, "These horrifying numbers show that we are facing an emergency allergy.
"The number of children with allergies and those suffering from severe allergic reactions is increasing year by year at an extremely alarming rate. "
Hassan Arshad, professor of allergy and clinical immunology at the University of Southampton, says the figures confirm" a worrying increase in severe food allergy. "
" We must remember that behind each of these numbers is a child or an adult who has suffered the worst effects of anaphylactic shock, "he said.