Skin discoloration is a change in the natural color of the skin. It may appear as an area that is darker than the surrounding skin (hyperpigmentation), lighter than the surrounding skin (hypopigmentation), or completely without pigment (depigmentation). Discoloration can affect a small spot, a larger patch, or multiple areas of the body. While many pigment changes are harmless, new, persistent, or changing discoloration should be evaluated to identify the underlying cause.
Skin Darkening
Textural Change
Skin Lightening
What Causes Skin Discoloration?
Skin color is largely determined by melanin, a natural pigment produced by cells called melanocytes. Discoloration can occur when the skin produces too much or too little melanin, when melanocytes are damaged or destroyed, or when another condition changes the color of the skin.
Common causes of skin discoloration include:
- Sun exposure, which can increase melanin production and contribute to freckles, sunspots, uneven skin tone, and melasma
- Inflammation or skin injury from acne, eczema, psoriasis, burns, cuts, rashes, or cosmetic procedures, which may leave darker or lighter areas as the skin heals
- Hormonal changes related to pregnancy, hormonal birth control, or other hormone therapies, particularly in people with melasma
- Autoimmune conditions such as vitiligo, in which the immune system attacks melanocytes and causes sharply defined white patches
- Genetic factors or inherited pigmentary conditions
- Fungal or other skin infections that can alter pigmentation
- Certain medications or chemical exposures
- Underlying health conditions, including some thyroid, metabolic, nutritional, or circulatory disorders
- Benign growths, birthmarks, or moles
- Precancerous or cancerous skin changes
Some discoloration develops without a clearly identifiable cause. Because many pigment conditions can look alike, a dermatologist can determine whether a color change is harmless or needs further testing.
What Are the Symptoms of Skin Discoloration?
The primary symptom is a visible change in skin color. Depending on the cause, discoloration may appear suddenly or develop gradually. It may remain stable, fade, spread, or become more noticeable with sun exposure.
Signs and symptoms can include:
- Brown, tan, gray, blue, red, purple, or white spots and patches
- Areas that are lighter or darker than the surrounding skin
- Symmetrical discoloration on both sides of the face or body
- Irregular or sharply defined borders
- Small spots that enlarge or merge into larger patches
- Uneven skin tone after a rash, acne breakout, burn, injury, or procedure
- White or gray hair within an area of pigment loss
- Itching, scaling, tenderness, redness, or changes in texture when an inflammatory or infectious condition is present
Many pigment disorders, including melasma and vitiligo, may not cause pain or itching. A lack of discomfort does not always mean the discoloration should be ignored, especially when it is new, spreading, or changing.
How Is Skin Discoloration Diagnosed?
Diagnosis usually begins with a review of your medical history and a careful examination of the affected skin. Your dermatologist may ask when the discoloration began, whether it has changed or spread, whether a rash or injury came first, and whether you have experienced recent sun exposure, hormonal changes, new medications, or chemical exposure. Your personal and family history of pigment disorders, autoimmune disease, and other health conditions may also help identify the cause.
Depending on the appearance and suspected cause, the evaluation may include:
- A visual and physical examination of the color, pattern, borders, texture, location, and distribution of the affected skin
- A Wood’s lamp examination, which uses ultraviolet light to make certain pigment changes more visible and help distinguish between conditions
- Dermoscopy, a magnified examination that allows the dermatologist to evaluate pigment and structures beneath the skin’s surface
- A skin scraping or other testing when a fungal infection is suspected
- Blood tests when an autoimmune, thyroid, nutritional, or other systemic condition may be contributing
- A skin biopsy, in which a small tissue sample is examined under a microscope, when the diagnosis remains uncertain or the area has concerning features
Not every patient needs laboratory testing or a biopsy. The recommended evaluation depends on the pattern of discoloration, accompanying symptoms, and your medical history.