I have suffered from severe allergies, including anaphylactic reactions, which have been life threatening. I've had congestion and breathing difficulties, which can easily be controlled with an emergency inhaler, but mostly, I experience "edema" which is fluids that build up in various regions of my body. Oh, and it moves around too. It's too bad when it goes into my fingers or toes, and it gets a little embarrassing when it goes into my mouth, making my lips puff up like balloons, but it's also gone into my throat, threatening to cut off my breathing, or into the corneas of my eyes, which not only distorts my vision, but runs the risk of causing permanent damage to my eyesight.
I took all the patch tests too, numerous times, but they never really isolated the problem because apparently, allergies can "wax and wane", meaning that for some, they can come and go. According to those patch tests, I'm either allergic to almost everything, or nothing.
Bottom line is my allergies flare up when I'm either sick and my immune system is weakened, or under stress, and dissipate otherwise. So I work really hard at keeping as healthy as possible through diet and exercise, and I can't prevent stressful situations, but control how they effect me, by utilizing various stress management techniques, including meditation, yoga and self-hypnosis.
I still carry an epi-pen and emergency inhaler, but haven't had to resort to using either for quite some time. So far, so good.