2-4

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2-4. PHYSICAL FINDINGS OF INSPECTION--COLOR

a. Normal Skin Pigments. Three elements are responsible for skin color: melanin, a pigment in the epidermis; carotene, a pigment mostly in the dermis; and blood in the capillaries found in the dermis. The amount of melanin causes the skin color to vary from pale yellow to black. Melanin is found primarily in the basale and spinosum layers of the skin and produced in cells called melanocytes. These cells are located either just beneath or between the cells of the stratum basale. The number of melanocytes is about the same in all races. Skin color differences in the races are due to the amount of pigment the melanocytes produce and disperse. An individual without pigment in the skin, hair, or pupils of the eyes is termed an albino. This person has inherited an inability to produce melanin. In other people, melanin has a tendency to form in patches called freckles. Carotene, a skin pigment found in Oriental people, when mixed with melanin accounts for the yellowish hue of Oriental skin. The pink color of Caucasian skin is due to blood in capillaries in the dermis without a heavy pigment in the skin to mask the color. Blood in the capillaries close to the surface of the skin is also responsible for the color of nailbeds, lining of the eyelids, oral mucose, and the underlying vascular bed.

b. Abnormal Skin Pigments. Abnormal skin pigments include hyperpigmentation, hypopigmentation, and erythema.

(1) Hyperpigmentation. Excessive pigmentation in the skin is termed hyperpigmentation. Chronic adrenal insufficiency causes hyperpigmentation. A patient may have increased pigmentation over his entire body, appearing to have a very good tan year round. Areas of the body that may become noticeably darker include points of pressure and friction such as elbows, knees, and scars; hair; and lines on the nails.

 

(2) Hypopigmentation. Not enough pigmentation in the skin is termed hypopigmentation. The striking contrast between skin with pigment and skin without pigment confused people in ancient times, who confused hypopigmentation with leprosy. In the case of vitiligo, there is a loss of pigment in the skin, mucous membranes, and hair bulbs.

 

(3) Erythema. This term refers to redness of the skin. An individual with a fever will have erythema. Also, sunburned people and those with superficial infections will have reddish-colored skin.

 

(4) Cyanosis. Cyanosis is a bluish discoloration of the skin, lips, and nail beds caused by insufficient oxygen in the blood. Cyanosis can be caused by congestive heart failure; pneumonia; or congenital heart disease with right-to-left shunts.

 

(5) Localized red or purple changes to the skin. Vascular neoplasms, birthmarks in Von Recklinghausen's disease, and hemorrhage into the skin can cause the skin to be red or

purple colored. Vascular neoplasms change the skin color. Sturge-Weber neoplasms are cherry red in color. A hemangioma (a benign tumor made up of blood vessels) may be port wine colored or bright red as in a senile hemangioma or bright red and raised as in a strawberry birthmark. Birthmarks in Von Recklinghausen's disease are light brown spots on the skin. These spots are sometimes called cafe au lait spots. Spontaneous bleeding in the subcutaneous tissues, another condition, causes the appearance of purple patches on the

skin. In petechiae, bleeding into the skin appears as purplish-red spots on the skin, nail

beds, and mucous membranes. In ecchymosis, blood from injured vessels escapes and black and blue spots appear on the skin.

 

(6) Decrease in hemoglobin content. Persons suffering from anemia or shock will have pale skin.

 

(7) Changes in skin color caused by pigment deposits. In jaundice, the yellow pigmentation of the skin and/or sclera of the eye is caused by the high levels of bilirubin (an orange-red pigment) in the blood. In carotenemia, increased carotene in the blood causes the skin to look yellowish.

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