Itchy red bumps in summer can be caused by hives, eczema, prickly heat and so on. 1. Urticaria: It is a kind of edematous wind-balls confined to the surface of skin and mucous membranes, and the wind-balls can subside on their own. Accompanied by varying degrees of itching, resulting in small red bumps in the summer itchy. 2. Eczema: Eczema is a kind of skin disease with many triggers, which can be manifested as erythema, papule, papule herpes, accompanied by itching. It may also cause itchy red bumps in the summer. 3. Prickly heat: Prickly heat, also known as sweat rash or heat rash, is a superficial inflammatory skin disease commonly seen in summer or hot and humid environments, manifested as small blisters, pimples, etc., which can lead to small red bumps and itching in summer. There are many other causes of itchy red bumps in the summer, and it is recommended that patients seek timely medical attention to clarify the cause of the disease and then carry out regular treatment to avoid adverse consequences.