Gefitinib is a kind of anti-tumor drug, commonly used in the treatment of non-small cell lung cancer; the redness on the face after taking Gefitinib may be caused by skin allergy or febrile side effects, and it is necessary to adjust the dosage of the drug as well as the treatment method appropriately according to the cause of the disease, and discontinue the use of the drug if necessary, and then take general treatment or medication to alleviate the symptoms. 1. Skin allergy: long-term use of Gefitinib may cause allergic reactions, resulting in skin allergy, redness, red rash, and may be accompanied by itching, swelling and pain and other symptoms. If it is only a slight abnormality, no special treatment can be done; if the symptoms are serious, it is necessary to reduce the dosage appropriately or change to other anti-tumor drugs, such as paclitaxel. If the symptoms are serious, it is necessary to reduce the dosage or switch to other anti-tumor drugs, such as paclitaxel. 2. Side effect of fever: after using Gefitinib, some patients may just have simple body fever, resulting in redness of the skin. If the symptoms are not serious, no special treatment can be done first, and regular observation can be done; if the symptoms are serious, then switch to gemcitabine as prescribed by the doctor. When using Gefitinib, you should know that it is prohibited for those who are allergic to the drug components, children, and during pregnancy; it should be used with caution during breastfeeding or for those who have liver function impairment. Long-term use of Gefitinib, in addition to the face will become red, may cause abdominal pain, diarrhea, nausea, vomiting, loss of appetite, usually stop the drug after the symptoms will be relieved on their own. If you need to use Gefitinib, be sure to do it under the guidance of a professional physician to avoid causing adverse reactions.