Wu Long San: An External Powder for Reducing Swelling and Relieving Pain
“Wu Long San” (Five-Dragon Powder) comes from Waike Chuanxin Ji (A Record Handed Down of External Medicine). Its composition is: Tiannanxing (raw Arisaema) 30g, Sheng Banxia (raw Pinellia) 15g, Quan Danggui (whole Angelica) 15g, Sheng Dahuang (raw Rheum) 15g, and Chen Xiaofen (aged wheat flour; now toasted medical starch may be used instead) 620g. Grind all the above into a fine powder. When heat is exuberant, mix it with hibiscus juice (juice pressed from hibiscus flowers; if unavailable, fresh bamboo sap may be substituted); when cold is predominant, mix it with ginger juice, and apply to the affected area, changing the dressing once daily.
Wu Long San has the actions of invigorating blood and resolving toxins, and reducing swelling and relieving pain. It is indicated for early-stage welling-abscesses and flat abscesses (yong-ju), deep-rooted boils (ding-du), and scrofula (luoli). Raw Banxia and raw Tiannanxing are highly toxic Chinese medicines, dangerous when taken internally, but relatively safe for external application. Raw Banxia and raw Tiannanxing are very effective at reducing swelling and relieving pain, and modern pharmacological research shows they also have good anticancer effects. However, because of their great toxicity, both are controlled drugs that are not easy to buy; if unavailable, processed Banxia (Fabaxing) and prepared Arisaema (Dannanxing) may be substituted, though the effect is not as good as with the raw forms.
External application works through transdermal delivery to treat local benign and malignant tumors as well as boils. Generally, as long as the patient's affected area is not broken, side effects are controllable. However, some people with more sensitive skin are easily irritated during application, and blisters may form. If such patients experience adverse reactions after using Wu Long San, they should stop promptly. The ancients also attended to medication safety: welling-abscesses, boils, and scrofula in their early stage—that is, just as they begin—are not yet ulcerated, so external application at this time is relatively safe.
Wu Long San can be used generally for benign tumors, malignant tumors, and boils. In TCM external medicine, welling-abscesses include both benign and malignant tumors; deep-rooted boils belong to the boil-like diseases and are mostly infectious; scrofula includes lymphoma, as well as tuberculous lymphadenitis and ordinary lymph-node enlargement.