Inspection of the Skin and Diagnosis of Diseases
The skin is the superficial covering of the human body, with hair, vellus and sweat glands attached to it. The skin is an external barrier of the human body with Weiqi (defensive energy) circulating through it; it is also connected with the lungs. The external pathogens first attack the skin when they invade the body; and the pathological changes of qi, blood and internal organs can also be shown on the skin through meridians.
Inspection of skin color:
Red skin: Fresh red skin may appear in patients with Dandu (erysipelas); the disease with red cloudy patches on the skin migrating all over the body is called Chiyou Dandu (wandering erysipelas), caused by excess of heart fire and attack of wind-heat pathogens or due to fetal poison in babies; and the local red and swollen skin on the lower limbs is called Liuhuo (erysipelas); it is due to accumulation of kidney fire and down-ward pouring of damp-heat pathogens.
Yellow skin: Yellow color of the skin of the body and face, eyes and nails, much deeper than the color of the skin of normal people, indicates jaundice. Bright yellow skin like orange peel in patients with yellow sweat, dark yellow urine, thirst and yellow greasy tongue coating is usually caused by damp-heat pathogens in the spleen and stomach or in the liver and gallbladder; and dark smoky yellow skin in patients with chills, tastelessness in the mouth and white greasy tongue coating is due to stagnation of cold dampness pathogens in the spleen and stomach.
Black skin: Blackish yellow skin may appear in patients with Heidan (blackish jaundice), derived from ordinary jaundice, and it is called Nulaodan (sexual intemperance jaundice) if caused by sexual intemperance. Dark black or blackish sallow skin of face or whole body at the late stage of edema is due to extreme exhaustion of kidney essence. Black or brown patches on the skin are caused by stagnation of liver qi and blood stasis, accumulation of damp-heat pathogens in the body, deficiency of Yin and excess of fire pathogens, or deficiency and dysfunction of the spleen.
Inspection of the moisture of the skin:
Moist skin and hair indicate sufficiency of Taiyin qi; dry skin and hair indicate deficiency of Taiyin qi; shrunken skin and loss of hair indicate lung damage; and dry haggard skin and broken hair indicate exhaustion of lung Yin. Inspection of the hair and vellus can determine the nature of a disease (deficient, excessive, cold or heat) and the location of pathogens (superficial or deep). Erect hair and vellus is due to attack of deficient pathogens in patients with chills. In general, dry and broken vellus indicates a bad prognosis; and moist and intact vellus indicates a good prognosis. Skin as dry as fish scales is known as Jifu Jiacuo (dry scaly skin), and the patients with this type of skin and dark eyelids may suffer from abscess or accumulation of dry blood in the body if they also suffer from acute pain in abdomen.
Lichenous skin like snake slough all over the body and ulcerated skin without pus are all signs of Lifeng Pibing (skin lesion of leprosy).
Inspection of swelling and distension of the skin:
Swelling of the skin (edema) may appear on the head, face, chest, abdomen, back, waist and limbs; and distension (ascites) appears only on the abdomen. Diseases in patients with swollen supraclavicular fossa, soles of the feet, back and umbilicus due to edema are difficult to cure.
In patients with thin and bright skin, local or general edema is often pitting in nature. Edema starting from the face and spreading to the limbs and rest of the body in patients with symptoms of common cold is called Fengshui (edema caused by wind pathogens) due to impairment of dispersion of lung qi and blockage of circulation of body fluid; edema starting from the limbs and slowly spreading to the rest of the body in patients with tiredness of limbs, poor appetite and diarrhea is due to accumulation of water and dampness in the spleen and dysfunction of the spleen; and edema starting from the waist and lower limbs and gradually spreading to the rest of the body, but more remarkable in the waist and lower limbs of patients with soreness and weakness of the waist and knee, coldness in the stomach, cold limbs and clear urine is due to deficiency of kidney Yang and impairment of the metabolism of the water in the body.
Dim, lusterless and swollen skin without pitting is due to stagnation of liver qi and poor circulation of qi; and local red swollen skin with intractable itching and pain is due to insect bite or caused by insect poison accumulated in the skin and
Inspection of poxes on skin:
Pealike poxes on skin are often accompanied with symptoms of exterior syndrome. The pox lesions of the skin can be divided into smallpox and chicken pox ones.
Smallpox: Round poxes of different sizes may appear simultaneously with red halo, deep root, depressed vesicle pit and turbid vesicular fluid like pus, and the pock marks may be retained on the face after the crusts have been peeled off.
Chicken pox: Oval poxes of different sizes may appear in succession with thin vesicle membrane easily ruptured, clear thin vesicular fluid but without vesicle pit, thick crust and pock marks left on the face.
Inspection of skin rashes:
Skin rashes contain macules and papules. The red, flat and smooth macules not detectable by palpation can be divided into Yin and Yang types; and the red miliary papules detectable by palpation may appear in measles, German measles and urticaria.