A new study by James Cook University says for those allergic to fish, one bite of the reptile's meat could lead to life-threatening anaphylaxis.

The study's co-author Thimo Ruethers said immunological reactions to crocodile meat were examined in 77 children allergic to fish.

"Fish-allergic patients underwent allergen skin-prick testing to crocodile and various types of fish," he said.

"Skin reactions and comprehensive blood analyses then showed that the vast majority - about 70 per cent - of patients would likely have an allergic reaction when eating crocodile."

Alligator and crocodile meat are increasingly popular as a healthy alternative protein source.

However, recent reports of anaphylaxis after eating crocodile meat have been associated with a major fish allergen - a protein triggering a cascade of immune responses which can result in an allergic reaction.

Dr Ruethers said the crocodile allergen, a generally harmless protein called parvalbumin, was the first reptile allergen registered.

"We have now coined the term 'fish-crocodile syndrome'," he said.

"Fish-allergic individuals may be at risk of serious allergic reactions upon consumption of crocodilian meat due to them being highly reactive to crocodile parvalbumin.

"This generally harmless protein is now the very first reptile allergen registered with the World Health Organisation."

Australian Associated Press