Skin Discoloration: 8 Common Causes & Treatment Options

Skin discoloration can appear on the face, hands, arms, or other parts of the body and is often linked to sun exposure, hormonal changes, or skin irritation. Common causes include freckles, melasma, shaving irritation, and sun spots, which may darken over time without proper care.

Some types of skin discoloration, such as seborrheic keratosis or acanthosis nigricans, are related to aging or underlying health conditions like insulin resistance. In rarer cases, skin discoloration may be associated with melanoma, especially when spots have irregular borders, multiple colors, or continue to grow.

Treatment depends on the cause and may include sunscreen use, topical creams, exfoliation, or procedures like laser therapy and chemical peels. Medical evaluation is recommended when skin discoloration changes in size, shape, or texture, or is accompanied by itching, flaking, or other unusual symptoms.

Common causes of skin discoloration are:

1. Shaving

Shaving with a razor can irritate the skin and lead to dark spots, which may become more pronounced with repeated shaving. This type of discoloration is most common in the underarms and groin area.

What to do: To help lighten razor-induced spots, a dermatologist may recommend skin-lightening creams or specific aesthetic treatments.

2. Freckles

Freckles, also known as ephelides, are small, light to reddish-brown spots that commonly appear on sun-exposed areas of the skin, such as the face and arms. They result from an increased production of melanin, the pigment that gives skin its color.

Freckles are usually genetic, but they may become more noticeable or increase in number with excessive sun exposure.

What to do: Freckles are harmless and do not require treatment. However, some people choose to lighten or reduce their appearance for cosmetic reasons. In such cases, a dermatologist may recommend topical lightening creams, retinoids, daily use of sunscreen suited to the person’s skin type, or laser treatments.

3. Sun spots

Sun spots are the most common cause of skin discoloration on the face, arms, or legs. They develop after years of sun exposure and are especially common after age 45. Without daily sunscreen use, these spots may darken over time.

What to do: Exfoliating twice a week can help even out skin tone. For more noticeable results, treatments such as laser therapy or intense pulsed light (IPL) may be effective. It is also essential to use sunscreen every day to prevent existing spots from getting darker and to reduce the risk of new ones forming.

4. Melasma

Melasma is a type of facial skin discoloration that often develops after long periods of sun exposure. It can also appear following a sunburn or during pregnancy because of hormonal changes. When melasma occurs in pregnancy, it is called chloasma gravidarum.

What to do: Apply a broad-spectrum sunscreen with at least SPF 30 every day. According to the American Academy of Dermatology, sun protection is an essential part of melasma care because sunlight can darken existing patches and trigger new ones. Avoid staying in the sun for extended periods, especially during peak hours.

During pregnancy, you can use a moisturizer containing vitamin C to help care for the skin. If the dark spots do not fade after pregnancy, other melasma treatments such as laser therapy, diamond peeling, or acid peeling may be considered.

5. Seborrheic keratosis

Seborrheic keratosis is a type of raised, dark growth that develops on the skin as part of the natural aging process. It is generally harmless and not a threat to health.

What to do: Seborrheic keratosis is a benign condition that usually doesn’t require treatment. However, you should consult a dermatologist so they can examine the lesion and any changes in color or appearance to rule out skin cancer.

6. Acanthosis nigricans

Acanthosis nigricans is a common skin condition often seen in people with diabetes because it’s mainly linked to insulin resistance. It may also develop in association with conditions such as polycystic ovary syndrome (PCOS) or metabolic syndrome. The condition causes darkened, thickened patches of skin, typically due to hormonal imbalances.

What to do: It’s important to identify the underlying cause so that it can be treated appropriately. Your doctor may recommend adjusting your diet to help control blood sugar levels, getting regular physical activity, and taking medication if needed.

You can also gently exfoliate the affected skin once a week with a mixture of liquid soap and sugar to help reduce the discoloration.

7. Phytophotomelanosis

Phytophotomelanosis is a skin reaction that happens when citrus juice (such as lime or lemon) on the skin is exposed to sunlight. The citric acid and vitamin C in the lemon react with ultraviolet (UV) rays, triggering inflammation that can lead to dark patches on the affected area.

What to do: Wash the skin thoroughly with soap and water, apply a cold compress to reduce irritation, and protect the area with sunscreen. In some cases, a dermatologist may prescribe a healing or anti-inflammatory ointment to help the skin recover.

8. Melanoma

Melanoma is a type of skin cancer that begins in melanocytes, the skin cells responsible for producing melanin, the pigment that gives skin its color.

It is often linked to excessive exposure to ultraviolet (UV) radiation from the sun or artificial tanning devices and usually appears as a dark spot with irregular borders that tends to grow over time.

According to the National Cancer Institute, suspicious pigmented lesions are often assessed using the ABCDE signs, including asymmetry, border irregularity, color variation, diameter, and evolution or change over time. Learn more about what melanoma looks like and when to see a dermatologist.

What to do: Any irregular dark spot or new area of skin discoloration should be evaluated by a doctor so that appropriate treatment can be started as early as possible. Melanoma treatment may include cryotherapy, immunotherapy, radiation therapy, or chemotherapy, depending on the stage of the cancer.