Yes, it could cause that. You need to keep your eyelash extensions clean otherwise you will risk the chance of developing Blepharitis. It is an eye condition that causes inflammation and possible infection of the eyelid because a blocked eyelash follicle. The blockage normally occurs from sebum, dead skin cells and bacteria on the natural lash follicle. And blepharitis could occur when you have poor eye hygiene. It could make your eyes red, itching, swollen, crusting, burning sensation as well. Hence, you have to clean your lashes for at least 2 to 3 times weekly if you do not makeup, and for nightly if you do makeup.