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.
Darkened skin can be the consequence of several so-called “patterns of disharmony” in Chinese Medicine.
Chinese Medicine sees the body as a system, not a sum of isolated parts. A "pattern" is when the system's harmony is disrupted, leading to symptoms or signs that something is wrong (like darkened skin here). It is similar to the concept of disease in Western Medicine but not quite: a Western disease can often be explained by several Chinese patterns and vice-versa.
A pattern often manifests itself in a combination of symptoms that, at first glance, do not seem necessarily related to each others. For instance here darkened skin is often associated with numbness in the limbs, numbness of the muscles and stifling sensation in the chest in the pattern “Phlegm in the Channels, joints and muscles”.
Once identified, patterns are treated using medicinal herbs, acupuncture, and other therapies. In the case of darkened skin we’ve identified that a herbal formula called Shen Tong Zhu Yu Tang can help treat the patterns behind the symptom.
In Chinese Medicine darkened skin is a symptom for the pattern "Phlegm in the Channels, joints and muscles". Below is a small explanation for it with links for more details.
Pulse type(s): Choppy (Se), Wiry (Xian)
The bone deformities that occur in chronic rheumatoid arthritis are seen as a form of Phlegm.
Phlegm in the Channels, joints and muscles is often treated with Shen Tong Zhu Yu Tang, a herbal formula made of 12 herbs (including Peach Kernels - Tao Ren - as a key herb). Shen Tong Zhu Yu Tang belongs to the category of "formulas that regulate blood", which might be why it is often recommended for this pattern. Its main action as a formula is: "Invigorates Blood".
Source date: 1830
Number of ingredients: 12 herbs
Key actions: Invigorates Blood. Unblocks painful obstruction. Relieves pain. Invigorate Qi. Dispels Blood Stagnation. Unblock Channels.
Because it is a formula often recommended to treat the pattern 'Phlegm in the Channels, joints and muscles' of which darkened skin is a symptom.
Its main actions are: Moves Stagnant Blood and regulates menses. Relieves pain caused by Blood Stasis.
Its main actions are: Moves Blood and breaks up Stasis. Moistens the Intestines. Relieves coughing.
Its main actions are: Regulates and moves the Blood. Relieves Wind-Cold and pain. Circulates the Qi in the Upper Burner, relieving headaches.