t uncommon for people to develop allergies later
in life. One explanation is as you get older,
your system works less efficiently, suffers small breakdowns, and allergies develop.
There is also the possibility that due to air quality and pollen counts (both seem to get worse every year), you may be having a reaction where you didn't before.
Also, it's commonly said that you develop allergic resistance to your own pet. After some months or so, your body will build up an immunity.