What is the problem with detached and peeling baby nails? Is it gray nail? Recently, there are more patients with abnormal toenails in the clinic. They all have one thing in common: the nail plate peels off from the root of the nail and gradually falls off, as few as 1 or as many as 20 nail plates can be abnormal. Hand, foot and mouth disease after healing nail disease has the following characteristics 1, mostly in the hand, foot and mouth disease 2-6 weeks after the healing of the finger and toe nail abnormalities; 2, nail plate abnormalities are characterized by: most of the thumb, index finger, middle finger first, gradually spread to the other nail plates of the hands and feet. When shedding, cloudy patches usually appear first at the nail half-moon, gradually expanding to the edge of the nail, mostly starting from the nail root and gradually separating and shedding the entire nail. The new pink nail can be seen under the peeled nail, and there can be a cross groove in the center; 3) nail fungus microscopy and culture negative, excluding gray nail; 4) trace elements are commonly iron, zinc, calcium deficiency, but can also be normal trace elements. So why is the nail plate easy to fall off after the healing of hand, foot and mouth disease? The reason is not very clear at present, checked the literature, it is said that the following possible reasons, the proximal nail matrix in the growth of the virus or the body’s immune response to the influence of the nail matrix cells in the process of maturation and differentiation is inhibited, while the distal nail matrix cells normal maturation and differentiation, resulting in the dorsal and ventral parts of the nail to the upper and distal migration is not synchronized, and finally the formation of nail loss, so the culprit or cause hand, foot and mouth disease Therefore, the culprit is still the coxsackievirus that causes HFMD.