One minute three-year-old Oscar Dustan will be running around and the next he can be sitting in tears for no apparent reason.
That is the effect of the medication he needs following a bone marrow transplant to try to combat life-threatening acute myeloid leukaemia – known as AML.
Dad Ryan, from Asfordby, said: "It has turned our world upside down.
"I have a big smile on my face every day but inside I am dying.
"I have to be here and have to be strong for Oscar, my wife, Tania, and daughter, Anna-May, who is two.
"I know there are a lot of people in a worse position but I don't mind admitting there are times when I have a good cry."
Oscar was two-and-a-half when he was diagnosed with AML.
Ryan, 31, said: "It was last July and Oscar became really lethargic.
"He just wasn't himself. He would want to go to bed early and he had a few nose bleeds.
"We went to our GP a few times and they thought it was a chest infection.
"Oscar wasn't getting better and an out-of-hours clinic in Oakham referred us to Leicester Royal Infirmary for a scan and blood tests.
"Later, two nurses came up to us, took us into a room and told us it was leukaemia.
"I felt sick and scared. I just wished I could make it me instead of him. I think I almost broke Tania's hand by squeezing it so hard."
Oscar was transferred to hospital in Nottingham, which specialises in treating AML.
There, he was given courses of chemotherapy over the next few months.
Ryan, a chef, said: "Tania, a hairdresser, and I had to give up our jobs.
"I would stay at the hospital from Monday to Friday and she would be there Friday to Monday.
"Oscar was a shell of himself, it was horrible. He didn't get out of bed for the first six weeks and had to learn to walk again because his legs had wasted away."
The youngster made it home for his third birthday on December 19 and Christmas Day but, at his monthly check-up in February, Ryan and Tania, 28, were devastated to hear the AML had returned.
Doctors said the only option was for Oscar to have a bone marrow transplant and he was transferred to hospital in Sheffield. Ryan said: "We were very lucky to get a 100 per cent match."
The transplant, a nine-hour infusion, was the easy part.
"Oscar has to go back to clinic every week and there is always the worry his body will reject the donor cells," said Ryan.
However, coping with their son's illness is just one aspect to the family's changed world.
Ryan said: "You meet others going through the same journey, there is a little oncology family. Out of the 16 children we knew since Oscar was diagnosed, only Oscar is left now. The oldest was 14 and the youngest, very young.
"In a way, it makes you feel as if you are just waiting but Oscar is doing all right at the moment.
"He is on loads of medication, including steroids, which has the side-effect of big mood swings.
"One minute, he will be hyper and the next crying for no reason and there is no consoling him."
The other difficulties have been financially and emotionally.
Ryan said: "We couldn't have managed without the Clic Sargent charity.
"The support, financially and emotionally, has been phenomenal.
"Tamsin, the Clic Sargent social worker, allocated to us in Nottingham, has helped us through so much.
"She did all the paperwork to help us apply for grants – I wanted to make sure we'd still be able to put a roof over the kids' heads.
"But there is all the emotional support, too – Tamsin is always there to speak to.
"If all's well in two years' time and Oscar has fully recovered, it would be fantastic.
"We could plan more than a few days ahead and not having the worry of having to go for hospital checks the whole time."
Dr Simone Stokley is a consultant paediatric haematologist at Nottingham University Hospitals NHS Trust.
She said: "Acute myeloid leukaemia (AML) is quite rare in children. There are only about 70 cases in the country each year.
"It does require intensive treatment and children with AML will require four blocks of chemotherapy over about a six-month period.
"This has to be given in hospital so children will have to spend most of that time as an inpatient.
"Most children do not need to have a bone marrow transplant."
specialist
Because the number of patients is so small, there are about 10 specialist centres in the country treating children. Nottingham is one of those centres.
Dr Stokley, below, said: "We cover the whole of the East Midlands and see about seven patients a year.
"We don't know why one child gets this and not another."
She added: "We are hoping to begin a paediatric clinical trial into treatment, hopefully next year.
"It is likely to include colleagues in France because the numbers are small.
"We will be looking to get information about a new drug, and there are new drugs coming through, and a trial will help in guiding treatments in the future."
