The appearance of small red dots on the legs that become more itchy the more you scratch them requires careful observation of the appearance of the small red eyes. If the small red dots have red papule-like changes and are raised to the touch of the hand, and the texture does not show keratosis-like changes, consider insect bite dermatitis or papular dermatitis caused by going to the mosquito bite, or it may be a nodular inflammation in a restricted area. If the red dots are densely arranged, hard to the touch, amyloid change, consider the skin amyloidosis, and long-term skin friction, irritation caused by local skin tissue thickening related. If the red dots do not fade after pressure, it is considered to be allergic purpura, which is caused by allergic factors that increase the fragility of blood vessels, resulting in the accumulation of blood inside the blood vessels under the skin, and may also be eczema.