Skin is distributed over the surface of the body, connected with the lung with weiqi circulating inside. Skin is the defending barrier of the body and nourished by qi, blood and body fluid through meridians. So the disorders of the skin itself and the disorders of viscera can be reflected by the skin. Inspection of the skin is not only helpful for diagnosing skin disorders, but also helpful for under- standing the nature of the disease, the conditions of the viscera and the states of qi and blood.
The normal skin colour of the yellow race is similar to complexion and appears reddish and yellowish, moist and lustrous, elastic and smooth, which are signs of sufficiency of body fluid and essence.
Inspection of skin mainly concentrates on the colour,shape and pathological changes of the skin, such as macules, eruption, miliaria alba, abscess, carbuncle, boil and furuncle.
Inspection of colour
The diagnostic significance of inspection of skin is similar to that of inspection of complexion.
Inspection of shape
Dropsy of skin is due to spreading of dampness; dry skin is due to consumption of body fluid or depletion of essence and blood; dry and rough skin like scales is called squamous skin due to mixture of blood asthenia with blood stagnation and malnutrition of the muscles and skin.
Inspection of skin disorders
Many skin diseases and general diseases may bring about the changes of the colour and shape of the skin. The following are some of the commonly encountered ones.
Inspection of macules: Macules refer to reddish or purplish uneven patches on the skin and can be divided into yang macules and yin macules.
or purplish and silk texture or cloud like macules with fever, dysphoria and fast pulse is called yang macules, usually seen at the exuberant heat stage in exogenous febrile disease due to exuberant heat scorching blood and driving blood to extravasate. Bright red macules appearing on the chest and abdomen first and gradually extending to the four limbs with freshment of the spirit after abatement of fever is the sign of outgoing of pathogenic factors, suggesting favourable prognosis. Thick, deep red or purplish macules, or appearing first on the four limbs and gradually extending to the chest and abdomen with continuous high fever and even coma, is a sign of extreme exuberance of virulent heat and internal sinking of pathogenic factors, suggesting unfavourable prognosis.
Light colored or purplish thin macules with varied size, unfixed location, occasional appearance and disappearance, pale tongue and weak pulse are yin macules, usually seen in miscellaneous diseases of internal impairment resulting from failure of qi to control blood and extravasation of blood.
Inspect ion of erupt ions: Eruptions refer to reddish points like millet or petals that can be felt by hands and fade when pressed. Eruptions may appear in various diseases, such as measles, rubella and urticaria.
Measles is an acute epidemic eruptive disease in pediatrics, usually due to attack by exogenous morbillous toxin. Measles is characterized by pink pockmarks which appear first over the hairline and face, gradually extending to the trunk and four limbs and disappearing after full eruption. Pink-colored and evenly-distributed measles with orderly eruption, orderly disappearance, abatement of fever and desquamation after eruption is favourable, suggesting that healthy qi dominates over pathogenic factors and that the prognosis is favourable. Deep red or purplish and thick or evenly mixed or unevenly erupting or sudden vanishing measles accompanied by high fever and asthmatic breath is unfavourable, suggesting that pathogenic factors dominate over healthy qi and that the prognosis is un-favourable.
Rubella is a commonly encountered acute epidemic disease in pediatrics, usually caused by exogenous virulent heat. Rubella is characterized by light red colour, small size, sparse distribution, more distribution" on face and neck, less distribution on four limbs, itching skin and no desquamation after disappearance of eruption.
Urticaria is a cutaneous disease caused by internal accumulation of damp heat complicated by invasion of pathogenic wind which is stagnated in the skin. It may be caused by allergy. Its eruption is marked by various size of macules which are in the size of pockmarks or soybean,protruding on the skin, occasionally emerging and disappearing. It is quite itching and appears in patches after being scratched.
Miliaria alba. Miliaria alba refers to a kind of small whitish blisters on the skin characterized by brightness like millet, protrusion over the skin and unchanged colour over the root. There is serous fluid in miliaria alba which comes out when scatched. The blisters are distributed over the neck, chest and abdomen, occasionally over the four limbs and never on the head. There is desquamation after disappearance of miliaria alba. It is usually caused by retention of exogenous damp heat in the skin and inhibited sweating, often seen among patients with damp and febrile disease. Miliaria alba with bright colour and full serous fluid is called crystal miliaria alba, suggesting sufficiency of fluid, capability of healthy qi to dominate over pathogenic factors, outgoing of damp heat and favourable prognosis. Miliaria alba with white and dry colour and no serous fluid is called dry miliaria alba, suggesting insufficiency of fluid, failure of healthy qi to dominate over pathogenic factors and unfavourable prognosis.
Carbuncle, phlegmon, boil and furuncle. Carbuncle, phlegmon, boil and furuncle appear on the surface of the body and are usually treated in surgery.
Carbuncle- Carbuncle refers to local swelling with tense root and accompanied by hot sensation and pain. Carbuncle is of yang syndrome and is characterized by quick onset, susceptibility to ulceration and liability to healing. It is usually caused by internal accumulation of damp heat and virulent heat, stagnation of qi and blood as well as exuberance of heat and decaying of muscles.
Phlegmon. Phlegmon refers to extensive swelling without tip, changes of skin, fever and pain. It is of yin syndrome marked by gradual onset, longer duration, difficulty in dispersing, ulcerating and healing. It is usually caused by asthenia of qi and blood, stagnation of cold and phlegm, or internal accumulation of virulence of wind which migrates in the muscles, deepens into tendons and bones as well as stagnates qi and blood.
Boil: Boil appears like millet at first with hard deep root, numbness or itching, white top and pain, followed by bright redness, pyrexia, aggravation of swelling and sharp pain. It is usually caused by accumulation of heat in the viscera, complicated by virulence attacking the skin, resulting in stagnation of qi and blood.
Furuncle: Furuncle appears superficially on the skin with small and round size, red swelling, pyrexia, mild pain, susceptibility to suppurate and ulcerate and liability to healing after ulceration. It is usually caused by internal accumulation of virulent heat, or by stagnation of summerheat dampness in the skin which stagnates qi and blood.