Library

Itching in external sores is most common in skin diseases, such as scabies and tinea (Ji Xuan), urticaria (You Feng), dampness sinking (Shi Zhu), eczema (Shi Chuang), impetigo (Huang Shui Chuang), and blood-wind sores (Xue Feng Chuang). Among the most prominent cases, tracing back to their causes, they are nothing more than wind-dryness and damp-heat. The nature of wind is agile and migratory; once it invades the skin and muscles, it scatters in all directions, thus often causing generalized itching, with a sensation like insects crawling on the surface of the skin. However, if wind is excessive, it leads to dryness; even if scratched until bleeding occurs, the wounds tend to close up quickly. Regarding measles or rashes triggered by wind exposure leading to "Sha Chuang" (local dialect refers to leprosy-like scabies; "Sha Chuang" is a common term in the Wu region), which persist for years without healing, dampness generates heat, and accumulated heat breeds parasites, causing particularly severe itching. The lesions spread invasively, with frequent discharge of yellow fluid, easily causing erosion and decay, and are highly contagious. This represents disease caused by the excess of dampness. For conditions such as urticaria, eczema, and sores with yellow pus crusts, both itching and ulceration occur; the more they ulcerate, the more they itch. This constitutes another category of itching belonging to damp-heat.

In the case of tumorous sores (Zhong Yang - un-ulcerated swellings), there is usually no instance of itching. If it does occur occasionally, those located in the upper part must involve transformation into wind, while those in the lower part must involve transformation into dampness. Only during the stage when Ding Chuang (carbuncle) presents with massive swelling, where the pathogenic toxin has not yet reached its peak and pus has not yet formed, is there sometimes itching within the muscle tissue that spreads diffusely. This indicates the dispersion of Ding toxin and is the most critical prognosis. Unless the root perimeter is consolidated and the pus toxin is vented, there is fear that the toxin will sink inward and attack internally, causing rapid disaster. This is the most contraindicated situation for itching. Similarly, for Nao Bei Ju (abscess on the back of the head/neck) presenting with boundless diffuse swelling and inadequate pus drainage, occasional itching poses similar harm. In contrast, for ulcers (Kui Yang - ulcerated sores) where pus discharge is smooth but residual swelling around the periphery remains, slight itching may occasionally occur. This signifies the gradual resolution of swelling and the flow of Qi and Blood, representing a favorable sign. There are also instances where after necrotic tissue has detached and new granulation tissue is abundant, slight itching occurs between the skin and flesh due to the elimination of the old and establishment of the new, and the infusion of Qi and Blood. However, this must be mild, faint, distant, and subtly distributed to indicate gradual improvement. Alternatively, after ulceration, if the condition was initially stable but suddenly becomes intolerably itchy, this is neither due to external wind invasion nor damp-heat stagnation, and the swelling will inevitably worsen. In such cases, one must respond flexibly according to the specific manifestations. One must not rigidly adhere to the view that itching in ulcers invariably indicates impending recovery.