Blepharochalasis is a rare inflammatory syndrome consisting of episodic, painless bouts of eyelid edema and erythema lasting a few days at a time. Quiescence can last as long as a couple of years between active phases, but patients usually experience a couple of active "attacks" per year. Long-term changes include increased eyelid folds, eyelid atrophy, pigmentary changes, and thinning. Blepharochalasis usually presents in adolescence and typically affects both upper eyelids, but unilateral and lower eyelid cases have been reported. Reports suggest a female predominance.

The exact pathogenesis of blepharochalasis is unknown, but there have been hereditary and immunologic links. Hormonal changes occurring during puberty may be a factor in the development of blepharochalasis. Motegi et al reported histological examination revealing perivascular and interstitial infiltration of lymphocytes in the dermis with a marked decrease of elastic fibers. Immunofluorescence analyses suggested that MMP-3 and MMP-9 might play a role in the development of blepharochalasis as well. Others have shown increased immunoglobulin A (IgA) activity.

While blepharochalasis is usually idiopathic and sporadic, a link has been suggested to the rare Ascher syndrome (swollen upper eyelids and lips, occasionally in conjunction with a euthyroid goiter).

No specific causative triggers or exposures have been reported, but patients may report preceding allergy symptoms, crying, fevers, bee stings, stress, or physical activity.