Skin nodules refer to masses that appear on the skin, either raised above the skin surface or embedded within it, with a hard texture and a round or round-like shape. Their size, depth, surface color, and whether they ulcerate vary depending on the disease cause. Pulse taking and palpation are more effective than inspection in distinguishing this condition.

In classical medical texts, there is no record of "skin nodules." The term "scrofula" mentioned in the Lingshu under the section on cold and heat is originally a disease name. However, based on the description "small ones are called scrofula, large ones are called scrofula, continuous like a string of beads," it seems to be the earliest record of this condition. "Subcutaneous node" appears as a disease name in the Qianjin Yaofang and as a symptom in the Jingyue Quanshu. The Waike Dacheng

describes: "Subcutaneous nodes grow between the skin and the membrane, like a kernel in a nut, hard but not painful." Additionally, there are references to "phlegm nodules." Terms like scrofula, subcutaneous node, and phlegm nodule encompass both disease names and symptoms. From the perspective of the latter meaning, they can be included in the scope of this condition. For ease of discussion, they are uniformly named "skin nodules."

Although skin tumors, scars, and warts share some similarities with this condition, their disease causes are fundamentally different, and their clinical manifestations also differ. Therefore, they are not within the scope of this discussion.

bubble_chart Pattern Analysis

1. Phlegm-fire Congelation︰Initially, one or several bean-sized nodules appear, unchanged in skin color, hard to the touch, movable upon pushing, painless, and without fever or chills. They gradually enlarge, accompanied by mild pain, and begin to adhere to each other, becoming immovable upon pushing, resembling a string of beads, clearly countable. Over time, the skin turns deep red, the texture softens, and upon rupture, thin pus discharges, with prolonged non-healing. In the early stages, symptoms are mild, but over time, symptoms such as afternoon tidal fever, loss of appetite, muscle wasting, dry skin, a red or deep red tongue with scant coating, and a deep, thin, rapid pulse may appear. This condition arises from lung-kidney yin deficiency, where deficient fire internally scorches and transforms into phlegm, leading to phlegm-fire congealing and forming nodules. As fire tends to flare upward, phlegm follows the fire’s path, so nodules often appear on the neck, armpits, and other areas. Visually, they resemble a string of beads, clearly countable, with unchanged skin color initially, turning deep red over time. Upon palpation, they are hard and movable initially, softening later, possibly rupturing and discharging thin pus, with prolonged non-healing. The pattern of yin deficiency and internal heat (such as afternoon flushing, muscle wasting, a red or deep red tongue with scant coating, and a deep, thin, rapid pulse) is evident. Treatment involves nourishing yin, reducing fire, and resolving phlegm, commonly using Yin-Nourishing and Fire-Reducing Decoction combined with Nodule-Resolving Powder.
2. Damp Phlegm︰The nodules initially appear scattered and sparse, the size of sesame seeds, and gradually enlarge to the size of soybeans, round or semicircular, densely clustered or isolated, light brown in color, firm in texture, with a rough surface and intense itching. They may also be accompanied by diarrhea, loose stools, anorexia, a pale tongue with a swollen body and teeth marks, and a wiry-slippery or deep-soggy pulse. The condition arises from spleen qi deficiency, impaired transportation and transformation, accumulation of water-dampness, and the congealing of phlegm-dampness, which overflows and gathers in the skin. Dampness is heavy and turbid, and when phlegm-dampness intermingles, it tends to sink downward, which is why the nodules most commonly appear on the lower limbs. The key diagnostic features of the nodules are: in the initial stage, they appear as scattered, sparse small granules, later becoming densely clustered or isolated, light brown in color, intensely painful and itchy, with a rough surface that feels obstructive to the touch, and they do not ulcerate. These two types of nodules have a prolonged course and develop slowly. However, they are accompanied by signs of spleen qi deficiency (diarrhea, loose stools, anorexia, a pale and swollen tongue with a greasy coating, and a deep-soggy pulse). Therefore, the treatment focuses on invigorating the spleen, drying dampness, and resolving phlegm, often using modified Two Old Ingredients Decoction and Sargassum Jade Flask Decoction.
3. Qi and Blood Stagnation︰The nodules are round or oval in shape, about the size of a broad bean or cherry. Initially, the surface complexion is bright red, gradually turning dark red or purplish-red, slightly raised above the skin, with spontaneous pain and severe tenderness upon touch. They generally do not suppurate or ulcerate but may be accompanied by local swelling, fever, sore throat, joint pain, a red tongue with scant coating, and a wiry-choppy or deep-wiry pulse. This condition commonly occurs on the lower legs due to internal dampness-heat descending into the blood Maijing vessels, leading to obstructed qi and blood circulation. Qi stagnation results in blood stasis, which stagnates in the Jingmai and forms nodules. The characteristics of these nodules vary depending on their location: (1) Those occurring on the extensor side of the lower leg appear red or bright red, are smaller and more superficial, more numerous, do not ulcerate, and tend to recur after subsiding; those on the flexor side appear dark red, are larger and deeper, fewer in number, may ulcerate, and are slow to heal. (2) Nodules on the extensor side often present acutely and are more common in spring, while those on the flexor side follow a chronic course, worsening in winter and improving in summer. The primary treatment principle is to unblock the collaterals and dispel stasis, regulating qi and resolving stasis. The commonly used formula is the Tongluo Huoxue Decoction. The extensor side of the lower leg is traversed by the three yang meridians of the foot, and the syndrome tends to be excess in nature. Thus, adjunct herbs such as Unprocessed Rehmannia Root, peony bark, Dyers Woad leaf, and Lonicera can be added to cool the blood and clear heat. The flexor side is traversed by the three yin meridians of the foot, and the syndrome tends to be deficient, especially after ulceration of the nodules. In such cases, Tangshen, roasted astragalus, and Prepared Rehmannia Root should be added to tonify qi and blood.
4. Cold-dampness Obstructing Collaterals︰The nodules initially appear without redness or swelling, gradually enlarging and turning red over time. They commonly occur on the limbs, distributed in a band-like pattern, with their numbers increasing progressively. Over time, they may ulcerate, discharging thin, pale yellow pus, and cord-like indurations may form between the nodules. Generally, there are no systemic symptoms. Associated manifestations include cold hands and feet, dull skin complexion, a pale tongue with a white and greasy coating, and a deep-tight or wiry-slippery pulse. This condition is often caused by skin trauma, allowing cold-dampness pathogenic qi to invade and stagnate in the Jingmai, leading to the formation of nodules. Hence, the nodules frequently appear on exposed areas such as the hands, feet, and lower legs. Due to the stagnation of {|104|}cold-dampness{|105|} in the {|106|}Jingmai{|107|}, cord-like indurations may be observed between the nodules. Initially, the nodules are neither red nor swollen, but as they enlarge, they turn purplish-dark without pain. Upon ulceration, they discharge thin, greasy fluid and are slow to heal, often distributed in a band-like pattern along the limbs. Treatment should focus on dissipating cold and eliminating dampness, as well as tonifying and replenishing qi and blood. A commonly used formula is Zirong Sanjian Tang.
5. Epidemic Qi Infiltration︰The newly formed nodules are light red, yellow, or normal skin color, while the old nodules are dark red or reddish-brown. In the advanced stage, the face is covered with nodules of varying sizes, uneven and often accompanied by cold, heat, pain, itching, reduced sensation, or partial loss. The tongue is red with scant coating, and the pulse is thin and rapid. This is due to inherent weakness and occasional exposure to epidemic qi, which invades the blood vessels, with nodules mostly appearing on the face. These two types of nodules have distinct characteristics: the newly formed ones are light red or reddish-yellow, while the old ones are dark red or reddish-brown. In the late stage [third stage], the face often becomes uneven and is frequently accompanied by numbness and coldness in the hands and feet. Treatment should focus on tonifying qi, dispelling wind, activating blood circulation, and killing worms. Commonly used internal remedies include the Wind-Dispersing Powder and Mafeng Pills, while externally, Sophora decoction is applied for washing.