Swollen lips and cheek

Hi, welcome to the ehealth forum and I am glad to help you.
You seem concerned by the probable allergic reaction to some unknown antigen with swollen left side cheek, swollen lips.
Slight reactions with mild symptoms usually respond to nonprescription allergy medications. An oral antihistamine, such as diphenhydramine (Benadryl) may be used along with steroids. These medications should be taken for only a few days. The pathophysiology of allergic responses can be divided into two phases. The first is an acute response that occurs immediately after exposure to an allergen. This phase can either subside or progress into a "late phase reaction" which can substantially prolong the symptoms of a response, and result in tissue damage. After the chemical mediators of the acute response subside, late phase responses can often occur. This is due to the migration of other leukocytes such as neutrophils, lymphocytes, eosinophils and macrophages to the initial site. The reaction is usually seen 2–24 hours after the original reaction. Cytokines from mast cells may also play a role in the persistence of long-term effects.
You must keep consultation with your personal physician as the diagnosis cannot be made online.
Hope this helps. Take care.
Note: This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.