Will Swelling from Allergies Harm Eyelid Surgery Healing?

 Usually having allergies after eyelid surgery does not impair wound healing, but it may prolong swelling post operatively.

No.
If you are otherwise healthy, then allergies can be annoying but do not hamper the healing process. You should make sure that you see an eye doctor before undergoing the surgery to ensure there is no other eye problem. Also, use Arnica Pills before surgery and Bromelain to reduce swelling and ice like crazy after surgery, 20minutes on then 20 minutes off for the first 3 days unless you are sleeping. Make sure not to take any medicine or over the counter pill like Motrin, Aspirin, Aleve etc. Also avoid Fish Oil, Omega 3s etc.
Regards.

Allergies should not affect the incision but the swelling may prolong the healing process. Eyelid incisions heal very quickly and usually extremely well. Swelling from allergies will not affect your final results.

Allergies will not harm the blepharoplasty incision. From a comfort standpoint, make sure your allergies are under control with antihistamines and cortisone nasal sprays. Antihistamines such as Claritin can be purchased over the counter, but the cortisone nasal sprays need to be prescribed by your physician.

Time saver,
Swelling from any source (allergy, medication, infection, etc) will prolong the healing time following any surgery. The more extensive the surgery and the more severe the swelling source, then the more prolonged the healing period.
Fortunately, plastic surgery limited to the upper eyelid with typical swelling most patients with allergies complain about should not be problem. Most patients will not notice a difference in the recovery period. Blepharoplasty eyelid incisions heal relatively quickly. Speak with your plastic surgeon performing the surgery and your allergist to best manage your specific allergies in the perioperative period. Best of luck.