http://news.bbc.co.uk/1/hi/health/7804443.stm
When diabetic Cliff Saunders became allergic to the insulin he used to control his condition he was worried.
"I felt I was not going to pull through and was thinking, 'how long have I got?'"
Cliff, now 66, from Essex, was first diagnosed 14 years ago with Type 2 diabetes.
His condition was controlled by diet and then tablets to stimulate insulin from his pancreas and to use his body's own insulin better.
But five years ago he had a mild stroke, and doctors prescribed two insulin injections a day to try to stave off another stroke.
These were small amounts at first, but the dosage was rapidly increased and Cliff soon suffered terrible reactions.
It worked like a dream and I thought 'eureka'
Cliff Saunders
"I started to experience itchiness and soreness and lumps on the skin. Then I started to feel hot sweaty, breathless and lethargic.
"During that period I tried five different insulins and still had no improvement.
"I was advised by the doctor that there was nothing he could do for me, and that I should just go home and take the tablets."
Tests showed that not only was he allergic to his own medication, but also to another four types - and it was the insulin molecule itself that was causing the problems.
Offering hope
Doctors painted a gloomy picture about Cliff's future, as it was clear the treatments he could take would not completely control his diabetes.
Determined not to give up, he started to do his own internet research and found that Dr Tahseen Chowdhury at Barts and the London Centre for Diabetes had treated difficult cases like his own.