Allergy shots
are a really long-term investment, yes. It's also a huge time commitment, but the first year is generally the worst there (twice weekly, or weekly injections). If you have decent insurance, they may be covered.
I will say that DD's six years of allergy shots literally changed her life. Ditto for her dad as a kid.
She still needs daily zyrtec, but I can usually count on one hand the number of times she uses a rescue inhaler annually, and she hasn't needed nasal steroids or Singulair in about three years.
No question that doing allergy shots altered the allergic march for her. No question.
When she started, she had OAS that was rapidly worsening and growing to include more and more fruit. Now, the only thing that she has trouble with are apples during birch (filbert) pollen season (we live in a filbert growing region, so the pollen levels can get crazy high).
Shots don't help everyone, of course-- and you won't really know which group you're in until you've been at it a year.