Cheerful news today suggesting that there is a point to all this.
Apparently allergies may indicate a metabolism that is geared up to preventing cancer. Does this apply to salicylate hypersensitivity, which is not a "pure" allergy? I don't see why not. The outcome is the same - an overactive immune system.
It's not a perfect shield against these awful diseases. But it's interesting to note that there is no experience of cancer amongst any of my blood relatives.
The researchers hint at the possibility that suppressing allergy with anti-histamines and singulair may not always be a good thing. I think everyone's experience is that it's a matter of balance - you don't want to be dependent on pills if you can manage it another way, such as by diet. But you've also got to maintain a healthy diet.