Localized redness, swelling and itching of the fingers may be related to insect bite dermatitis, but also may be caused by allergies, frostbite and other diseases, you should promptly go to the hospital dermatology department to identify the cause of the disease. 1. Insect bite dermatitis: after the patient’s fingers are bitten by insects, local skin allergies or inflammatory reactions can occur. The skin around the bitten finger may appear swollen, red, painful, accompanied by itching, and some serious patients may also have an allergic reaction, causing dizziness, dyspnea and other symptoms. 2. Allergy: If the patient’s fingers come into contact with certain allergic substances, such as topical medicines, plants, cosmetics, etc., an over-immune reaction may occur, resulting in itching, redness and clammy skin, and localized swelling may be caused. 3. Frostbite: due to long-term exposure of the fingers to cold, wet environment, skin vasospasm contraction, which leads to tissue hypoxia caused by cell damage, causing frostbite. Can occur in the fingers, toes and other limbs of the end or exposed parts of the finger itchy, local skin repeated erythema, swelling damage. In addition, hand eczema, tinea versicolor and other diseases can also lead to localized red, swollen and itchy fingers, but this symptom alone is not enough to diagnose the disease, and promptly consult a doctor for a clear diagnosis and targeted treatment.