Dark Spots on Skin

About the Symptom

Dark spots on the skin, or hyperpigmentation, occur when some areas of the skin produce more melanin than usual. Melanin gives the eyes, skin, and hair their color.

When to See a Doctor

Seek professional care if you experience any of the following symptoms

• Facial edema
• Edema
• Infertility
• Abnormal menstruation
• Headache
• Unexplained weight loss of 5% or more in 1 month
• Recent weight loss
• Easy fatiguability

Possible Causes

Generally, Dark spots on skin can be related to:

• Friction Melanosis

  This condition occurs when repeated rubbing of the skin with towels causes discoloration over the clavicle and spine.

• Acanthosis Nigricans

  A skin condition characterized by dark patches on the skin with a thick, velvety texture, usually seen in the neck, armpits, or groin region. It's typically seen in people with high insulin levels, ovarian cysts, thyroid or adrenal gland problems, certain drugs like birth control pills or steroids, cancer, etc.

• Malignant Melanoma (Including Nails)

  Malignant melanoma is type of skin cancer that develops in the skin cells that produce melanin (melanocytes), which is the pigment that gives skin its color. Malignant melanoma is most commonly found on the skin but can also be found in eyes, on fingernails, and on skin that does not get sun exposure (eg heels). It is diagnosed by biopsy. It may spread to lymph nodes or to other organs in the body quickly or in a delayed fashion.

• Varicose Veins, Chronic Venous Insufficiency, Stasis Dermatitis
• Atopic Dermatitis
• Nevus (Sebaceous Nevus, Pigmented Cell Nevus, Nevus of Ota, Epidermal Nevus)

• Edematous Sclerosis

• Senile Lentigo / Seborrheic Keratosis
• Anosacral Cutaneous Amyloidosis

Related Serious Diseases

Sometimes, Dark spots on skin may be related to these serious diseases:

• Adrenal Insufficiency (e.g. Addison Disease)

  The adrenal gland is an organ that releases hormones to control blood pressure and metabolism. In this condition, there are low hormone levels, and the causes include damage to the adrenal glands themselves or parts of the brain that control the adrenal gland. It can present with darkened areas of skin, extreme loss of body water, also known as dehydration, fatigue, weight loss that doesn't happen on purpose, nausea, vomiting or belly pain, lightheadedness or fainting, salt cravings, muscle or joint pains.

Doctor's Diagnostic Questions

Your doctor may ask these questions to check for this symptom:

• Do you have darkened skin?
• How has the darkened areas of skin changed since it started?
• How long have you had darkened areas of skin?

Find Similar Symptoms

References

• Thawabteh AM, Jibreen A, Karaman D, Thawabteh A, Karaman R. Skin Pigmentation Types, Causes and Treatment-A Review. Molecules. 2023 Jun 18;28(12):4839. doi: 10.3390/molecules28124839. PMID: 37375394; PMCID: PMC10304091.