Structural engineer Daniel Keeble, died from anaphylactic shock – an allergic reaction – but what caused his sudden collapse has baffled medical experts.
Sheffield Coroner Chris Dorries decided Mr Keeble probably suffered a violent reaction to something he had eaten but said: “I haven’t met its like in my 20 years as a coroner.”
The inquest heard that non-smoker Mr Keeble was a keen footballer and cyclist, he was rarely ill and only a moderate drinker.
He was enjoying a Christmas night out with 30 work colleagues when he got up without a word and went to the toilets in the upmarket Le Bistro Pierre restaurant in Sheffield’s Ecclesall Road.
When he did not return for his jacket and jumper his workmates thought he had gone home.
In fact he had collapsed and been sick in a locked toilet cubicle and was only discovered 24 hours later when his worried wife Tessa reported him to the police as a missing person.
Pathologist Dr Julian Burton told the hearing: “I think he probably died quite quickly, within minutes.”
Mr Keeble and his party ate from the regular menu available to all the restaurant’s customers throughout December last year.
It was not disclosed at the hearing exactly what he ate but nobody else in the group was ill and thousands of diners enjoyed the same food that month with no ill effects.
Common causes of anaphylactic shock include an allergy to nuts, fish, shellfish, dairy products and eggs. Non-food causes can include insect stings, latex, penicillin and drugs.
The latter non-food causes were all ruled out by the experts in Mr Keeble’s case and tests for a nut allergy proved negative.
Epilepsy, heart disease, viral and bacterial infections, abuse of medicines and substances were also ruled out.
Dr Burton said the only unusual finding was a high concentration of the naturally occurring enzyme tryptase which is released in the body when there is an allergic reaction. Levels of such enzymes are very high in people who have suffered anaphylaxis.
Mr Dorries asked how a healthy 25-year-old man could die in such a way. Dr Burton replied: “We don’t know. The likelihood is that he was allergic to something he had eaten. But what he was allergic to I don’t know. What triggered the anaphylactic response I don’t know.”
He said nothing could be picked out from his meal which would give a clue.
Mr Keeble had only drunk a couple of pints before going to the restaurant on December 10 and had some wine there. It was described as a “sensible” gathering and his blood-alcohol level was well under the drink-drive limit.
His wife said he seemed fine before going out and had said he didn’t want to be out late. She added: “I am at a loss as to why he should pass away so suddenly.”
In his findings, Mr Dorries said: “It is almost certain that his death has come about very quickly and I am quite clear that he has not been alive and unattended in the toilets for any length of time.
“There is good evidence that Daniel has suffered an anaphylactic reaction to something, most probably but not necessarily an innocent foodstuff. Indeed it may have been something that he had eaten or been exposed to previously without harm.”
The inquest was told Mr Keeble, who lived with his wife in Highfield, Sheffield, had suffered a brief bout of illness three months before his death.
Recording a narrative verdict, Mr Dorries said despite the efforts of the experts it was a “significant puzzle” why Mr Keeble died.