Can Untreated Under-eye Edema Lead to Permanent Skin Laxity?

Chronic eyelid swelling does lead to long term stretching of the eyelid skin. Trachoma is prevalent in Egypt which can be a cause of conjunctivitis and eyelid swelling. Please make sure you see an ophthalmologist who is testing you for trachoma and treating you appropriately. The damage that long term trachoma causes is much more significant that chronic eyelid swelling and the changes it causes to the eyelid skin.

The weight of excessive swelling on lower eyelid skin can affect the elasiticity of the skin. That would happen over a long period of time i.e., years but is possible. The more important issue is to find the reason behind it. You might have allergies or other ocular conditions. You should see ophthalmologists to find out the problem and the proper treatment.
Regards

It all depends on how much edema is present on the lower lids. If this is very severe edema of the lower lids, indeed it can create skin laxity by stretching the skin over several years if it is uncontrolled and untreated edema. It is important to find out why there is so much edema in that area. Make sure that you have an endocrine workup checking your thyroid levels as well as an allergy workup by your family physician. The recurrent conjunctivitis that occurs on the eyelids does create edema underneath the skin and if it is severe enough, it can create excess skin. Once the edema subsides there could be some mild excess skin present that can be addressed surgically once the medical condition is taken care of.

Yes, it is very possible to have the issue that concerns you. I would correct the allergies first than if the skin does not return to a more normal state than seek our help.
From MIAMI Dr. B

There is NO doubt that prolonged stretching of the lower lid skin by prolonged or recurrent lower lid swelling causes laxity and thining of the lower lid skin with a premature aged look.
I would recommend you see a good Allergist to see WHY you have persistent conjunctivitis. Such processes can be immune based or the result of bacterial or viral infection.

The simple answer is yes, conjunctivitis usually leads to edema around the eyes that can show up as bags. You should see an eye specialist to see why you have this problem. It is possible that you may not be closing your eyes completely when you are sleeping and this can lead to irritation to the cornea, gritty sensation and conjunctivitis.