The skin on the back of the foot turns black, which may be caused by post-inflammatory hyperpigmentation, ultraviolet radiation, and allergic purpura.
1. Post-inflammatory hyperpigmentation: If the patient’s dorsal skin suffers from eczema, dermatitis and other diseases, the inflammation will stimulate the local melanin synthesis is active, the melanocyte abnormal proliferation, thus causing the symptoms of hyperpigmentation, the dorsum of the foot skin blackened situation.
2. Ultraviolet irradiation: If you often wear slippers, the ultraviolet rays of the sun will stimulate the local skin, which will activate the melanin cells and secrete a large number of melanin particles to precipitate in the local area, resulting in the blackening of the dorsum of the foot.
3. Anaphylactic purpura: If the patient belongs to the allergic body, after contacting pollen, dust and other allergic substances, it will make the local capillaries dilate, thus causing skin inflammation and bleeding, and over time, there will be the symptom of the dorsum of the foot skin blackening.
When the dorsum of the foot skin darkening, it is recommended to go to the hospital in time, after clarifying the cause of the disease, under the guidance of the doctor, to give targeted treatment.