Redness, swelling and itching on the outside of the lower eyelid may be related to infection, granuloma, allergy and other factors, usually using medication, keep away from allergic substances, with life care. 1. Infection: The redness, swelling and itching on the outside of the lower eyelid may be infected with bacteria such as Streptococcus pneumoniae or Escherichia coli, which can be treated with ofloxacin or ciprofloxacin eye drops; the redness, swelling and itching on the outside of the lower eyelid may be caused by infection with cytomegalovirus or herpes simplex virus, which can be treated with acyclovir or ribavirin eye drops, and local personal hygiene can be done well. 2. Wheat swelling: the outer part of the lower eyelid is red, swollen and itchy, may be suffering from wheat swelling, mainly caused by staphylococcus infection, you can apply local hot compresses, the use of levofloxacin ophthalmic solution or ofloxacin eye ointment and other antibiotics. 3. Allergy: the lower eyelid outer red swelling and itching may be allergic, contact with allergic substances or ate allergic food caused by allergies, you can stay away from allergens, topical topical tobramycin dexamethasone ophthalmic ointment. The symptoms of redness, swelling and itching on the outside of the lower eyelid can be found in time to go to the regular hospital, the use of drugs need to be guided by the doctor.