Cold sores according to Chinese Medicine
The information provided here is not a replacement for a doctor. You shouldn't use it for the purpose of self-diagnosing or self-medicating but rather so you can have a more informed discussion with a professional TCM practitioner.
Catechu might help with cold sores
Why might Catechu (Er Cha) help with cold sores?
Because it is a herb specifically indicated to treat cold sores as can be seen on Catechu's page.
Catechu is a Neutral herb that tastes Bitter and Pungent. It targets the Heart and the Lung.
Its main actions are: Clear Phlegm. Clears Heat and drains Dampness. Applied externally for stopping bleeding.
Other symptoms often associated with cold sores
Cough with hot phlegm Excessive thirst Bleeding Eczema Bleeding hemorrhoids