There are a lot of red dots on the calves, which are considered to be caused by insect bite reaction, eczema, and anaphylactic purpura. 1. Insect bite reaction: the disease is mainly due to the patient’s calf area by mosquitoes, fleas, lice and other mosquito bites, mosquito secretions caused by skin allergic reaction. Patients are often in the bite site erythema, edema and other symptoms, and usually occur in batches, some patients will be manifested as a lot of red dots on the calf. 2. Eczema: the disease is a chronic, inflammatory, itchy skin disease, more common in the clinic, the specific cause is still unclear, most patients are due to immune abnormalities, endocrine level disorders and other factors. Patients often appear in the local skin erythema, followed by a small number of papular lesions, and the lesions will gradually spread to the surrounding area, some patients may appear to have a lot of red dots on the lower legs. 3. Henochromatosis purpura: this disease is a common clinical vascular allergic reaction disease, the specific cause is still unclear, clinical considerations and bacteria, viruses and other pathogens infection, genetic factors and other influences. The disease is prevalent in the patient’s limbs and buttocks, often leading to patients with localized purplish-red papules, and has a tendency to develop, the range of papules can be gradually spread, which led to the patient appeared in the calf a lot of red dots of the symptoms. It is recommended that patients with recent red dots on the calves should consult a doctor to determine the cause of the disease.