Epidermal cysts, insect bite dermatitis, boils and other diseases may be the cause of redness, swelling and hard lumps on the face. 1. Epidermoid cysts: skin damage, embryonic ectopic and other factors may lead to the appearance of epidermoid cysts, the disease is common in the face, upper trunk and other places, the patient will appear in the affected area of the skin swelling, hard and other symptoms. If bacterial infection occurs, local redness, swelling, pus symptoms. 2. Insect bite dermatitis: the onset of insect bite dermatitis is mostly related to insect bites, the patient’s skin will appear red, swollen, erythematous and blisters, firm papules and other symptoms, mostly in the exposed areas. 3. Boils: Boils are mostly related to Staphylococcus aureus infection, and may be triggered by high temperature environment and long-term alcohol consumption. Red, hemispherical nodules appear on the skin of the patient, accompanied by painful symptoms, mostly on the head, face, neck and buttocks. The causes of red, swollen and hard lumps on the face are different, so it is recommended that patients go to a regular hospital to clarify the cause of the disease and follow the doctor’s instructions for treatment.