Taiyang disease presenting with body itching, and Yangming disease presenting with a sensation of insects crawling on the skin, both result from deficiency of Ying and Wei Qi (Nutritive and Defensive Qi), where slight pathogenic factors remain in the exterior without an outlet. Thus, symptoms resembling insect crawling or itching occur. In all such cases, Guizhi Mahuang Ge Ban Tang (Cinnamon Twig and Ephedra Half-Combined Decoction) is appropriate.

When Taiyang disease persists for eight to nine days, resembling malaria with alternating fever and chills, where heat predominates over cold, the patient does not vomit, and bowel/bladder functions are relatively normal, occurring two or three times a day: if the pulse is slightly slow and relaxed (Huan), recovery is imminent; if the pulse is faint and aversion to cold worsens, this indicates simultaneous deficiency of Yin and Yang, and methods such as sweating, purging, or vomiting must not be used. If the face appears flushed, the disease has not yet resolved because slight sweating has not occurred to expel pathogens, leading to body itching; Guizhi Mahuang Ge Ban Tang (Cinnamon Twig and Ephedra Half-Combined Decoction) is indicated.

Yangming disease typically involves profuse sweating; if there is no sweating and the sensation of insects crawling under the skin occurs, it is due to chronic deficiency (Guizhi Mahuang Ge Ban Tang [Cinnamon Twig and Ephedra Half-Combined Decoction] is indicated; *Ren Shu* suggests Baizhu Fuzi Tang [Atractylodes Macrocephala and Aconite Decoction] or Huangqi Jianzhong Tang [Astragalus Middle-Jianzhong Decoction]).

Zhao states: The sensation of insects crawling under the skin is what the classics refer to as body itching. "Chronic deficiency" here refers to insufficiency of Exterior Qi and lack of Jin Ye (Body Fluids) nourishing the skin, causing dryness of Cou Li (Skin Pores) and difficulty in sweating. If one argues that deficiency requires tonification, since Yangming is affected by pathogenic factors, can pathogens be eliminated by tonification? Using herbs like Baizhu (Atractylodis Macrocephalae Rhizoma), Fuzi (Aconiti Lateralis Radix Praeparata), and Huangqi (Astragali Radix), which are astringent/sweat-retaining, would cause Ying and Wei stagnation, preventing pathogen expulsion and generating internal heat. Moreover, there are no signs of Stomach deficiency such as vomiting or diarrhea; the pathology is not in the interior but involves deficiency of Exterior Qi at the skin level. The principle should be harmonization. It is advisable to borrow Ge Ban Tang (Half-Combined Decoction); if heat is present, Chaihu Guizhi Tang (Bupleurum and Cinnamon Twig Decoction) may be used. Such sweet-acrid formulas can harmonize Ying and Wei, circulate Jin Ye, and resolve the exterior. Whether this is correct remains open to discussion.

Cheng states: Chu Zhong (Elimination of the Center) refers to a condition where internal Cold should prevent eating, yet the patient suddenly desires food. There are two presentations, both belonging to Jueyin disease with Zang Cold. One results from the erroneous administration of cooling medicines like Huangqin Tang (Scutellaria Decoction) and carries a fatal prognosis. The other presents with less heat and more cold limbs; if Stomach Qi remains, recovery is certain. However, one must fear sudden, transient appetite followed by death (a sign of impending Yang collapse); if heat persists, survival is likely. This is not caused by medication error.

In Shanghan (Cold Damage), if the pulse is Chi (Slow) and after six or seven days, Huangqin Tang (Scutellaria Decoction) is erroneously given to clear heat: since a Slow pulse indicates Cold, using Huangqin Tang further removes warmth, causing abdominal coldness and inability to eat. If the patient suddenly eats, this is Chu Zhong (Elimination of the Center), indicating certain death. Symptoms include blurred vision, inability to speak, yet increased grain intake. Although the mouth wishes to speak, the tongue cannot move. Whenever cold limbs and diarrhea are present, and the patient eats despite indications not to, suspect Chu Zhong. Offer Suobing (noodles/dough strips); if fever ensues after eating, it is Chu Zhong; if no fever occurs, it is not. (See detailed discussion in the Jueyin chapter).