Darkening of the skin on the dorsum of the foot area may be related to trauma, or it may be related to allergic purpura, chronic eczema and so on.
1. Trauma may cause the blood vessels under the skin to rupture and bleed, and when the blood is not discharged from the body, bruising will be formed, and localized darkening and bruising of the skin will occur.
2. Henochromatosis purpura is a vascular metamorphosis disease caused by allergy, infection, etc., which can lead to an increase in capillary permeability and brittleness, and in the clinic, it will also show up as scattered patchy ecchymosis, and when the blood volume is large, it may lead to bruising and blackening of the skin.
3. Chronic eczema is a chronic inflammatory disease, due to the prolonged onset of the disease may lead to local skin melanin precipitation.
Due to the complexity of the etiology, a doctor’s consultation is required.