Red dots on the feet, if red dots appear on the back of the foot, do not fade when pressed, and have no self-conscious symptoms, consider it may be purpura. Purpura that does not protrude from the skin on the back of the foot may be related to tight shoes and socks, squeezing, and does not require excessive treatment and can usually recover on its own. If the rash is large and palpable and accompanied by other symptoms, such as joint discomfort, rash on both lower extremities and fever, the possibility of allergic purpura is considered high. It is recommended to seek medical attention in time, and you need to improve blood routine, coagulation function, C-reactive protein, urine routine and other tests. Allergic purpura can sometimes involve the kidneys, it is recommended to continuously monitor the urine routine and pay attention to the urine protein and occult blood. At the same time, you need to give antihistamine loratadine and cetirizine orally, together with vitamin C and rutin tablets, and you must pay attention to rest and avoid straining.