Medical Health Encyclopedia

Skin - abnormally dark or light

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Vitiligo, drug induced Vitiligo on the face Incontinentia pigmenti on the leg Incontinentia pigmenti on the leg Hyperpigmentation 2 Post-inflammatory hyperpigmentation - calf Hyperpigmentation w/malignancy Post-inflammatory hyperpigmentation 2

Overview Treatment

Skin - abnormally dark or light

Definition:

Skin that has turned darker or lighter than normal does not usually indicate a serious medical condition. See also skin color, patchy.

Alternative Names:
Hyperpigmentation; Hypopigmentation

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Considerations:

Normal skin contains cells called melanocytes that produce the brown skin-coloring pigment melanin. There are several conditions in which melanocytes are either abnormal or abnormally distributed. Most skin conditions that cause discoloration are harmless.

A pale area of the skin is the result of fewer or less active melanocytes than usual, whereas a darker area (or area that tans more easily) indicates more numerous or more active melanocytes.

Sometimes mistaken for a suntan, bronzing of the skin often develops gradually starting at pressure points such as the elbows, knuckles, and knees and spreading from there. It is also seen in the creases of the soles of the feet and the palms of the hands. The bronze color can range from light to dark (in fair-skinned people) with the degree of darkness due to the underlying cause.

There are several types of benign hyperpigmentation that occur normally. However, any persistent hyperpigmentation that has not been medically explained should be examined by a dermatologist.

Common Causes:

• Exposure to the sun
• Medications
• Endocrine diseases such as Addison's syndrome
• Vitiligo

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