Scaly skin refers to localized or widespread dryness and roughness of the human skin, which feels prickly to the touch and resembles the skin of a toad or fish scales.

Ancient medical texts have numerous records of this condition. The *Jingui Yaolue* names it "scaly skin"; the *Zhubing Yuanhou Lun* refers to it as "snake body," "snake skin," "snake scales," and later generations, based on its symptoms, have given it various names such as "snake fetus," "toad skin disease," and "forest frog oviduct skin."

Conditions involving skin scabs, desquamation, thickening, rhagades, or foxtail millet-like papules leading to roughness are discussed separately under specific entries.

bubble_chart Pattern Analysis

1. Blood Deficiencywind-dryness︰The skin gradually turns gray, becoming dry and rough, resembling snake or lizard skin, or even crocodile skin. The scales adhere tightly to the skin, appearing as dirty or grayish-white patches with edges curling upward. Between the scales, there are white grooves forming a网状 pattern, and the texture feels prickly to the touch. This condition is most pronounced on the extensor surfaces of the limbs but can also spread across the entire body, though the face is rarely affected. Symptoms may temporarily alleviate in summer but worsen in winter, occasionally accompanied by itching. Skin near the joints may crack, causing pain. It is often accompanied by dry mouth and throat, reduced sweating, a pale tongue with scant moisture, thin white coating, and a deep, thin, weak pulse. This syndrome falls under the categories of "snake body," "snake fetus," "snake skin," "snake scales," or "snake physique." It typically manifests from childhood, primarily due to congenital insufficiency and postnatal deficiency of spleen qi, leading to inadequate nourishment of the skin and resulting in scaly skin. The skin exhibits small brownish scales resembling snake or fish scales, dry and rough, predominantly on the extensor surfaces of the limbs. Symptoms are milder in hot summers but aggravated in cold winters. Treatment should focus on {|###|}nourishing blood and moistening the skin{|###|}, as well as {|###|}enriching yin and promoting fluid production{|###|}. The recommended formula is Nourishing Blood and Moistening Skin Decoction.
2. Blood-heat Wind-dryness︰The skin lesions initially appear as dry, hard papules the size of foxtail millet grains, with vellus hairs passing through them, feeling prickly to the touch. Later, they merge into patches with a reddish base, commonly occurring on the extensor surfaces of the elbows and knees, and in severe cases, spreading over the entire body. The skin becomes dry and scaly, accompanied by metatarsal keratosis and rhagades, thickened nails, grade I itching, and a relatively slow disease progression. The tongue texture is red, and the pulse is thin and rapid. This condition often occurs in young individuals with an innate constitution of blood heat, caused by emotional disturbances leading to the five minds transforming into fire, resulting in blood heat transforming into dryness and generating wind. The characteristic features include erythema, itching, and skin as hard as a file. Treatment should focus on clearing heat and cooling blood, dispelling wind, and moistening dryness. The recommended formula is the Cooling Blood and Moistening Dryness Decoction.
3. Dampness-heat︰The skin lesions are symmetrically distributed on the neck, behind the ears, face, around the nose, and may even extend to the limbs and the midline of the chest and back, but can also be distinctly unilateral. They worsen in summer and alleviate in winter, accompanied by subjective itching. Initially, they present as hard follicular papules that feel rough to the touch, with normal skin color. Later, the surface becomes covered with greasy, grayish-brown crusts, which darken over the years and coalesce into verrucous plaques, often accompanied by a foul odor. The tongue texture is red with ecchymosis and a yellow, greasy coating; the pulse manifestation is slippery and rapid. This condition often arises from excessive consumption of spicy, fried, or rich and fatty foods, leading to internal accumulation of dampness-heat, obstruction of the collaterals, and malnutrition of the skin, resulting in skin roughness. The skin is not red but appears rough, covered with dirty-looking scales, and exhibits verrucous hyperplasia as its characteristic feature. Treatment should focus on {|###|}clearing heat and dispelling dampness{|###|}, {|###|}invigorating the blood to unblock collaterals{|###|}. The recommended formula is Dampness-Expelling Stomach Poria Decoction, taken with Rhubarb and Ground Beetle Pill.
4. Failure of Body Fluid Distribution︰The skin is extensively rough. Dense follicular keratotic papules resembling toad skin are present on the nape, trunk, elbows, and knees, feeling hard and prickly with a rasp-like texture. This is often accompanied by dry, irritated eyes and blurred vision. Additionally, there are small brown, keratotic lesions on the abdominal wall, waist, and buttocks, aligned with hair follicles, with a fixed center and slightly raised edges, resembling buckwheat-sized scales. The condition progresses slowly, worsening in winter and improving in summer. The tongue is pale with scant moisture, and the pulse is deep, thin, and weak. This syndrome falls under the categories of "toad skin disease," "snake scales," or "forest frog oviduct skin." It is often caused by irregular eating habits, overwork, excessive mental strain, or flavor predilection, which damage the spleen-earth. Impaired spleen function disrupts the distribution of body fluids, preventing them from reaching the skin, leading to rough skin or dense follicular keratotic papules that feel hard like a rasp and resemble toad skin in appearance. Treatment should focus on supporting the spleen and nourishing the stomach, as well as nourishing blood to moisten dryness. The recommended formula is Modified Atractylodes Rhizome Paste.

bubble_chart Documentation

1. Jingui Yaolue．Blood Impediment Deficiency Fatigue Abnormal Pulse Syndrome and Treatment: "Five kinds of strain, extreme deficiency, emaciation, abdominal distension and fullness, inability to eat, injury from food, injury from worry, injury from drinking, injury from sexual activity, injury from hunger, injury from overwork, injury to the nutrient-defense qi of the meridians, internal dry blood, scaly skin, dark circles under the eyes. To tonify deficiency and moderate the middle, Rhubarb and Ground Beetle Pill is the main treatment."