The itchy rash on the legs may be caused by mosquito bites, contact dermatitis or eczema. 1. Mosquito bites: mosquitoes are usually more in summer, if the legs are mosquito bites, it may lead to leg rashes and especially itchy symptoms. 2. Contact dermatitis: life in contact with some allergenic substances, such as animal fur, new pants, etc., can be accompanied by a rash on the calves, also accompanied by itching symptoms. 3. Eczema: Climate change and food allergies can lead to eczema. If eczema occurs on the legs, there are usually pimples and papules, accompanied by itching symptoms. If the above symptoms occur, it is recommended to go to the hospital in time for regular treatment.