Swelling of the upper eyelid incision may likely represent a localized cyst, either from a trapped suture deep in the skin or trapped epithelium under the skin. More concerning causes for this swelling may be infection / abscess or early scarring. Redness and swelling may also occur from topical ointments, either as an allergic reaction or secondary fungal infection. Most expected swelling and redness after blepharoplasty usually only lasts a short period time. Redness and erythema resolves more quickly than swelling.
Treatment of redness and swelling following blepharoplasty is relatively minor which may include a stopping topical ointments, minor revision procedure, stab incision and drainage of fluid, antibiotics, steroid injection, warm compress, and massage. Watchful waiting is another option, depending on complete evaluation.
Speak to your plastic surgeon, and discuss these various options, to help prevent potential complications after blepharoplasty.