There are many reasons why red bumps on legs are itchy, such as urticaria, contact dermatitis, eczema, insect bite dermatitis, nodular itchy rash and other causes. 1. Urticaria: a variety of factors stimulate the skin mucosa caused by a temporary increase in vascular permeability, skin limited edema occurs, resulting in itching of the skin wind, may lead to red bumps on the legs itchy symptoms. 2. Contact dermatitis: the skin on the legs in contact with sensitizing substances can cause a local inflammatory reaction, resulting in red bumps on the legs itchy symptoms. 3. Eczema: Inflammatory skin reactions caused by internal and external stimuli may also lead to itchy red bumps on the legs. 4. insect bite dermatitis: mosquito bites caused by skin allergies, may also lead to itchy red bumps on the legs. 5. nodular itchy rash: the cause is unknown, may be related to hypersensitivity reactions, mental factors, genetic factors, food and drugs, may cause red skin papules nodules, itching, can also lead to itchy red bumps on the legs. Red bumps itchy on the legs, there may be other reasons, you need to go to the hospital in time to check, follow the doctor’s instructions for treatment.