I developed allergies and asthma seemingly out of the blue at around 8 years old, and my allergies grew in scope over time. At first I was just allergic to cats, but eventually that became all animals with fur or feathers, tree pollen and dairy.
It's just speculation but in my case I think the factors at play were:
Genetics - nobody in my family has allergies but eczema and psoriasis are in the family and that can lead to higher chances of developing allergies
Smoking - my mother smoked while pregnant and for years after I was born. Grandparents were chain smokers too so I was exposed to tons of second hand smoke
Antibiotics - I don't know why or exactly at what age but there was a time when I was constantly getting ear infections (doctors often remark on the scars when they look in my ears), so I was on antibiotics all the time. If there is a natural balance of fungi and bacteria in our bodies, that was surely thrown off.
Today my asthma is mostly cured, I keep an inhaler just in case but use it less than once a year, but my allergies haven't improved at all.
I've had serious allergies for over 20 years and it had gotten worse over time especially when near an ocean (had to stop diving since it was near impossible to equalize with all the excess mucus).
But I recently became vegan and in about 2 weeks time, the allergies went away. I also have a friend who has asthma and when she went vegan, it all but disappeared. There's a lot of documentation about this but doctors don't give this advice probably because nutrition and prevention aren't a big part of their training.
But for anyone suffering, give it a try for a couple of weeks.
The quality of life gained is awesome.
FYI, this is the same scheme about me except there was only me and my sister getting eczema and nobody was smoking in the family.
About antiobiotics I had a treatment every fortnight that went from when I was 2,5 years old to when I was 6
It's just speculation but in my case I think the factors at play were: Genetics - nobody in my family has allergies but eczema and psoriasis are in the family and that can lead to higher chances of developing allergies Smoking - my mother smoked while pregnant and for years after I was born. Grandparents were chain smokers too so I was exposed to tons of second hand smoke Antibiotics - I don't know why or exactly at what age but there was a time when I was constantly getting ear infections (doctors often remark on the scars when they look in my ears), so I was on antibiotics all the time. If there is a natural balance of fungi and bacteria in our bodies, that was surely thrown off.
Today my asthma is mostly cured, I keep an inhaler just in case but use it less than once a year, but my allergies haven't improved at all.