What could cause recurring red & swollen skin around the eyes in my 18-year old son?

More info needed: For this type of issue, you should see a doctor. It may be as simple as allergies.

Blepharitis-dandruff: This is caused by blepharitis or dandruff of the eyelids. It is typically caused by a staph infection that is almost always curable with antibiotic ointment or eyedrops. Prevention is best accomplished by using one of the over the counter lid scrub formulas such as sterilid foam or occusoft cleansing medicated pads. No tears baby shampoo is an older treatment in scrubbing the closed eyelids.

Eye lid allergy: The eyelid skin is the thinnest skin on humans, and is prone to becoming irritated by chemicals that will not cause problems on other areas of skin, like the face, or arms. A skin allergy, to hair sprays or nail polish, can cause itching, swelling and redness on eyelids. You need only to use the spray once or week to have the allergy. It could also be eyelid rosacea? You may a skin doctor

Maybe allergies: Could be allergies or contact dermatitis or multiple other possibilities - if it persists or becomes concerning then i recommend seeing your primary provider.