Itching especially on the legs after every shower may be eczema, summer dermatitis, perifollicular keratosis, or ichthyosis, all of which may occur. In the case of summer dermatitis, itchy skin occurs because the local hair follicle sebaceous glands cannot effectively excrete sweat and sebum after entering summer, which accumulates on the skin surface. When stimulated by hot water or scalding during bathing, the surface skin expands, and the expansion will aggravate the skin irritation reaction by sweat and sebum, and the itching will increase. In case of keratosis pilaris or ichthyosis, due to the frequent blockage of hair follicle sebaceous glands or sweat glands, after bathing, sweat cannot be effectively discharged, which will also stimulate the itchy epidermis.