A rare teratogenic disorder due to acitretin or etretinate exposure during the first trimester of pregnancy, carrying a risk of fetal malformations of approximately 20%, including central nervous system, craniofacial, ear, thymic, cardiac and limb anomalies.

A fold of skin starting above the medial aspect of the upper eyelid and arching downward to cover, pass in front of and lateral to the medial canthus.