Bruises on the nail cover, if it is a trauma, no special treatment is needed, most of them will be absorbed by themselves, or grow out gradually with the metabolism of the nail. If it is allergic purpura, you can take prednisone tablets, rutin tablets and other drugs. 1. Trauma: The rupture of subcutaneous capillaries caused by external force and extrusion will cause bruising of the nail cover. If the area is small, most of it will be absorbed by itself and no special treatment is needed; if the area is large, it will grow out gradually with the metabolism of the nails, and with the growth of the nails. 2. allergic purpura: is a vascular inflammatory reaction, can cause subcutaneous capillary rupture, resulting in skin hemorrhages, skin bruises may also be manifested as nail cover bruises, you can take prednisone tablets, dexamethasone tablets and other glucocorticosteroid medication, at the same time, with rutin tablets, vitamin C tablets, to improve the permeability of the blood vessels. If you need to use medication for nail bruising, you should consult a doctor, and the medication should be used under the guidance of a doctor.