Puffiness with pain in the upper eyelid needs to be determined according to the actual situation, and then treated symptomatically. If unilateral upper eyelid swelling is accompanied by pain, it may be caused by allergies, inflammation or insect bites, or localized lesions in one eye, which can be seen from the appearance of the eye, such as granuloma, etc. Going to the dermatology department as well as the ophthalmology department for confirmation of the diagnosis will help to improve the treatment. If both eyes are swollen and painful, allergies and bilateral eye lesions are the most common causes. It is unlikely that a mosquito bite caused the swelling and pain in both eyes, but it is very unlikely to be caused by a systemic disease, as systemic diseases often cause swelling without pain.