Red spots on the calf do not hurt or itch, it may be allergic purpura, or it may be a blood clotting dysfunction caused by hematological system disorders, it is the local appearance of petechiae and ecchymosis.
1. Allergic purpura: antigen and antibody combine to form immune complexes deposited in the blood vessel wall, activating complement, leading to inflammation in and around the walls of capillaries and small blood vessels, and increasing the permeability of the blood vessel wall. Skin lesions manifested as pinhead to soybean-sized petechiae, ecchymosis, without pain and itching, pressure does not fade, that is, purpura.
2. Blood system diseases: If the patient suffers from blood system diseases, such as hemophilia, etc., the patient due to congenital lack of coagulation factors and lead to coagulation dysfunction, so that the bleeding spots in the calf area, usually painless and itchy.
In addition, the red spots on the calf which are painless and itchy may also be caused by other diseases. It is recommended that the patients go to the hospital in time, and give standardized treatment under the guidance of the doctor after a clear diagnosis, so as to avoid delaying the condition.