From a Chinese medical perspective, hayfever occurs from a weakness of lung energy. This is why some people can develop hayfever as an adult. Late onset hayfever can usually be pinned on a particularly bad cold virus contracted during the previous winter which would only serve to damage lung energy or 'qi'. A person with strong lung qi is able to defend themselves against allergens but once it has been weakened, it's very hard to build the energy back up as hayfever will only further weaken the lungs.
What an acupuncturist needs to do is build the lung energy back up in the autumn time to defend against winter viruses. When the qi is strong and robust it will do its job properly during the summer and won't allow hayfever allergens to attack.
Having acupuncture treatment in the autumn time can put pay to any future summer allergies. So now is exactly the right time to be throwing away the antihistamines & trying something natural for a more decongested summer!