Consultation of Ms. Shen, a Hebei reader: My father has rheumatism. Recently, the weather has turned cold, and his joints have begun to hurt again. The local doctor recommended a prescription for relieving pain: take an appropriate amount of white mustard seed, grind it into powder, mix it into a paste with warm water at about 50 ℃, spread it evenly on the cloth (the thickness of the ointment is about 1cm), paste it on the diseased joint, take it off one hour later, and wash the skin with warm water. Generally, the pain can be significantly alleviated after a few minutes of medication. Once every 3 days, three times continuously. Can I use this prescription?

Pu Zhaohe, associate researcher of the Information Research Department of Traditional Chinese Medicine of Chengdu University of Traditional Chinese Medicine, answered: Traditional Chinese medicine classifies rheumatism as "arthralgia syndrome", and believes that it is caused by the evil of wind, cold and dampness blocking the meridians and obstructing the flow of qi and blood.

External application of white mustard seed powder has a better effect on cold and wet joint pain, and the effective rate can reach 95%. It has the effects of dispelling wind and cold, removing dampness and dredging collaterals, diminishing swelling and relieving pain, and is mainly used to treat cold phlegm, asthma, cough, chest and flank pain, phlegm stagnation, meridians, joint numbness, pain and other diseases. The decoction of white mustard seed is mostly used to expel phlegm and drink, while for external use, it is better than dredging meridians and relieving swelling and pain. It is recorded in Rihuazi Materia Medica that white mustard seed "cures wind, toxic swelling and paralysis, and vinegar is used to grind and apply it". It is a commonly used drug in the "foaming therapy" of traditional Chinese medicine. After hydrolysis, the powder will stimulate the skin with fever, redness, and even blistering, thus achieving the effect of unblocking the meridians and regulating qi and blood. If the joint is blocked by blood stasis, redness, swelling and pain, it is better to add some vinegar to the paste to relieve pain and swelling. This method can also be used for pain caused by periarthritis of shoulder, tennis elbow, sciatica, lumbar muscle strain, etc.

It should be noted that the general application time should be controlled within half an hour to two hours. If there is strong burning or pain after sticking, it can be removed in advance; If only itching, fever and comfort are felt, the application time can be extended. After 1 day of medication, if there is local itching, it is a normal reaction and will disappear automatically after stopping the medication. However, it is not suitable for those with skin ulceration.