Salicylic acid has the ability to soften and dissolve the stratum corneum, and overuse can cause damage to the stratum corneum or even poisoning hazards. Due to the acidic effect of salicylic acid, it has a certain therapeutic effect on diseases caused by hyperkeratosis of the skin, such as perifollicular keratosis syndrome, sweat pore keratosis, follicular keratosis and other diseases. However, if the dosage is not appropriate, salicylic acid also has the effect of destroying the normal stratum corneum. After the destruction of the normal stratum corneum, redness, swelling, ulcers and other symptoms will occur. Salicylic acid absorbed into the blood vessels of the human body can cause salicylic acid poisoning, such as dizziness, shortness of breath, severe headache, tingling, and so on, and irritation or contact dermatitis can also occur. It is forbidden for those who are allergic to this product, and should be used with caution for those with allergies; pay attention to avoid contact with eyes and other mucous membranes, such as the mouth, nose, etc.; if the site of the medication has a burning sensation, redness, swelling, etc., the medication should be discontinued and the local medicine should be washed off, and if necessary, consult a doctor; it should not be used in broken skin; it is not suitable for long term and extensive use; it should be placed in a place where it is inaccessible to children, and children must be under the supervision of an adult to use it. Salicylic acid need to be standardized under the guidance of a doctor, do not self-medication.