外疡发痒，其最普通者，皮肤病为独多，如疥癣、游风、湿注、湿 、黄水疮、血风疮
等。其最着者，而溯其原因，则不外乎风燥与湿热二者而已。风性善行。袭入肌肤，则走窜
四注，故恒遍体痒搔，淫淫然如虫虱之游行于肌表。惟风胜则燥，虽搔破血溢，而随破
随收
龄痧疹冒风，恒发痧疮（兰 土语，谓之麻风疥。痧疮二字，乃吾吴俗之通称），频年累月
，不
湿生热，蕴热生虫，其痒尤烈，而浸淫四窜，黄水频流，最易蚀腐，且多传染，此湿淫为病
。凡游风、 疮、黄水脓窠诸疮，且痒且腐，愈腐而愈痒。此痒之属于湿热者，又其一也。
若肿疡则恒无发痒之例。即偶有之，在上部者，必兼风化；在下部者，必兼湿化。帷疔疮大
肿之时毒势未达，脓犹未成，颇有肌里作痒，淫溢四散者。此则疔毒之走散，最为危候。苟
非收束其根围，透达其脓毒，惟恐毒陷内攻，为祸甚速，是发痒之最忌者。而脑背疽之漫肿
无垠，脓不畅达，有时发痒者，为害亦同也。若溃疡流脓已畅，而四围余肿未消，亦有时
微微作痒。此肿势渐化、气血流通之朕兆，是为佳象。亦有腐肉已脱，新肌盎然，皮肉间
时作微痒，亦是除旧布新，气血贯注之故。但必以轻微淡远隐隐流布，方是渐入佳境。抑
或既溃之余，始尚相安，而忽尔奇痒难忍，则非外风之侵袭，即是湿热之郁蒸，肿势必随
之而更盛。是又当见景生情，随机应变。必不可固执一见，谓溃疡之发痒，定当作欲愈观也。
外科疮疡出现瘙痒症状，最常见于皮肤病，例如疥癣、游风（荨麻疹）、湿注（湿气下注）、湿疮、黄水疮、血风疮等。其中最为显著的情况，追溯其病因，不外乎风燥与湿热两类。风的特性是善于游走，侵入肌肤后，会流窜至四处，因此常常导致全身瘙痒，感觉像虫虱在皮肤表面爬行一样。然而，若风邪偏盛则会导致干燥，即使抓破出血，伤口也会随即收敛。至于痧疹因受风而引发的痧疮（吴地土语称为麻风疥，“痧疮”二字是吴地的通用称呼），常年累月不愈，湿气生热，蕴积的热气滋生虫邪，瘙痒尤为剧烈，且病变浸淫扩散，黄水频繁流出，最容易腐蚀腐烂，且具有传染性，这是湿邪泛滥致病。凡是游风、湿疮、黄水脓窠等各类疮疡，既痒又腐，越腐烂越瘙痒。这是属于湿热引起的瘙痒，是其中的另一种情况。
如果是肿疡（未溃破的疮疡），通常没有发痒的例子。即使偶尔有，位于上部的，必定兼有风邪化生；位于下部的，必定兼有湿邪化生。只有疔疮在大肿胀、时毒之势尚未透达、脓液尚未形成时，肌肉内部有时会出现瘙痒，并向四周扩散。这则是疔毒走散的表现，是最为危险的征候。如果不收束疮根周围，透出脓毒，恐怕毒邪内陷攻里，祸害发生得非常迅速，这是发痒中最忌讳的情况。而脑背疽漫肿无边、脓液排出不畅时，有时也会发痒，危害也是一样的。如果是溃疡（已溃破的疮疡）脓液排出通畅，但四周残余肿胀未消，有时也会微微发痒。这是肿势逐渐消散、气血流通的征兆，属于佳象。也有腐肉已经脱落，新肌生长旺盛，皮肉之间时常感到轻微瘙痒，这也是除旧布新、气血灌注的缘故。但必须是轻微、清淡、遥远、隐隐约约地分布，才是病情逐渐好转的迹象。或者在溃破之后，起初尚且平安，却突然奇痒难忍，这就不是外风侵袭，就是湿热郁蒸，肿胀之势必然随之更加严重。这时应当根据具体情况灵活应对，随机应变。绝不可固执己见，认为溃疡发痒就一定当作将要痊愈来看待。
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.