Swelling of the fingers after itching and scratching may be related to mosquito bites, angioedema, frostbite and other causes. 1. Mosquito bites: mosquito bites at the finger, mosquitoes release toxins can cause local inflammatory reaction, resulting in itching, red and swollen fingers. 2. Angioedema: also known as “giant urticaria”, hereditary or drug, food, dust allergies and other triggers, due to the expansion of small blood vessels in the subcutaneous loose tissues and increased permeability caused by limited edema. 3. Frostbite: low-temperature stimulation of finger vasoconstriction, resulting in tissue cell ischemia, hypoxia, local edema, itching can occur. It is recommended to go to the hospital in time after scratching the itchy fingers swelling, clear cause, under the guidance of the doctor for standardized treatment.