A very useful yoga asana for treating allergy problems at any time of year but particularly in spring time is Kashtha Takshanasana, or Wood Chopping.
Squat down, feet flat on the floor, knees apart. Clasp your hands together and stretch arms overhead on an inhale. Exhale as you bring arms back down, as if making a chopping motion with an ax. If possible, inhale through the nose and exhale through the mouth making a ”haaa” sound to expel all the air out of the lungs. Repeat the movement ten to twenty times, slowly. Keep hands clasped and elbows straight throughout.
Other benefits include firming chest, shoulder, upper back and pelvic muscles.
If you have difficulty maintaining a squat, the movement may be done from a standing position.