Summer skin itchy when sweating, may be due to physiological factors, eczema, cholinergic urticaria and other reasons, generally need to be treated according to the cause of the symptoms. 1. Physiological factors: If the weather is too dry and hot, sweating will lead to a faster loss of water in the body, resulting in dehydration of the skin, which may lead to itchy skin. 2. Eczema: Eczema is an inflammation of the superficial dermis and epidermis caused by internal and external factors. Clinical acute lesions to herpes mound, there is a tendency to ooze, the chronic phase to moss-like changes, easy to recur, often conscious itching, summer temperature rise, skin sweating can be conscious itching aggravated. 3. cholinergic urticaria: mostly in young patients, mainly due to exercise, heat, emotional stress, eating hot drinks or ethanol drinks, the deep body temperature rises, prompting cholinergic nerve impulses and the release of acetylcholine, which acts on mast cells and the onset of the disease. May appear in the heat sweating after the wind, self-conscious itching, sometimes only itching without skin lesions. Summer sweating itchy skin, there may be other reasons, you need to see a doctor as soon as possible, do not self-medication, so as not to cause aggravation of the condition.