By Jane Elliott
Health reporter, BBC News
Sally Anne Carey was resigned to the fact that she would die young.
The drug has transformed Sally's life
She had seen her father die from asthma and her own condition combined with serious allergic reactions had nearly killed her.
But she says her life has been transformed by a new drug, called Xolair, for hard-to-treat asthma.
Other severe allergic asthmatics, like Sally Anne, may soon be able to get the same drug because the NHS's drugs watchdog is set to make a final decision about its prescription.
The National Institute for Health and Clinical Excellence (NICE) has already agreed in draft guidance that Xolair (omalizumab) can be used for over 12s with "severe and persistent allergic asthma".
The drug, one of a range which can be used for this group, is injected in hospital every two to four weeks.
It works by dampening down the body's immune response, which can rage out of control in this allergic condition.
Sally Anne said her condition dogged and dominated her childhood.
"One of the earliest memories I have is of lying in an oxygen tent," said Sally Anne, who is 45 and from Surrey.
"As a child I could not go to other people's houses because something like a pet might trigger my asthma off. In the end they just stopped asking me."
Her asthma continued into adulthood.
In 1993 Sally Anne got pneumonia and her condition deteriorated. She went in and out of hospital, and developed a latex allergy making hospital stays fraught with danger.
In 1996 she got pneumonia again, and on Christmas Eve she started to feel dramatically worse.
She was hospitalised with breathing problems, but her condition deteriorated badly. She had to be resuscitated and was put on a ventilator.
Her family were warned she might not pull through and were told to say their goodbyes.
Sally Anne remained unconscious for two-and-a-half weeks. She was later told that she had suffered four cardiac arrests.
When Sally Anne came off the ventilator she was so weak that she could no longer walk.
She spent two months in hospital learning how to walk again.
Then, just months later, her father died at the early age of 61 from an asthma attack.
In 2000, Sally Anne was told that she would need a hysterectomy - but she was terrified that her latex allergy might flare up in hospital and prove fatal.
"Then a doctor at St Peter's Hospital asked me if I wanted to go on a trial for a new drug Xolair and I said I would try anything. I didn't know whether I was on the placebo or the drug, but I started to notice changes immediately," Sally Anne said.
"I had my hysterectomy and continued with the injections. I felt better and better and by the third month I knew I was definitely not having the placebo. I felt so good."
After the studies for Xolair came to an end, St Peter's Hospital in Chertsey, Surrey, managed to secure funding for Sally Anne's continued treatment with the drug from her local Surrey PCT.
How mucus (yellow) can block airflow in the lung in asthma
Seven years later, Sally Anne has had no hospital stays.
Although she still needs to use her asthma inhaler, she says her condition has dramatically improved.
She no longer needs time off her job as manager of a residential care home, she walks regularly and the family have even been able to get their own dog.
"There is nothing I can't do now," she said.
Dr Robert Niven, a respiratory consultant at the Wythenshawe hospital in Manchester, said the drug was extremely effective, but stressed that only a "very small percentage" of asthmatics were suitable for it.
"Xolair offers hope for patients with severe, persistent allergic asthma."
Neil Churchill, Chief Executive of Asthma UK, said: "Existing asthma treatments just don't work for around 500,000 people across the UK living with severe asthma.
"Xolair will be suitable for a small number of these people and will literally transform their lives. It will give them the opportunity to do the everyday activities that have always been a struggle or sometimes impossible, such as going to work, taking a holiday, having a night out or just walking to the shops.
"This treatment really can mean the difference between a life worth living and having no quality of life at all."