Skin Health More Skin Conditions Options for Treating Acanthosis Nigricans By Nicole Galan, RN Updated on November 18, 2022 Medically reviewed by Susan Bard, MD Print Acanthosis nigricans is a skin condition that causes patches of dark, thickened, velvety skin to develop on the neck, underarms, thighs, or groin. It isn't harmful or contagious, although you may not like its appearance. Acanthosis nigricans can be a sign of other medical conditions, so it's important to bring it up with your healthcare provider. Rawpixel / Getty Images Acanthosis Nigricans Symptoms With acanthosis nigricans, dark, thickened, velvety skin slowly develops in areas of the body where there are skin folds, typically the armpits, underarms, groin, and the fold of the neck. The pigmentation may also appear over the joints in the fingers and toes. The affected skin stays soft and doesn't toughen. Some people call the line on the neck the sugar line or sugar necklace (due to its association with diabetes). Less often, the pigmentation appears on the lips, palms, or soles of the feet, which is associated with cancer. Causes Acanthosis nigricans can affect otherwise healthy people, and it is not always related to a medical condition. However, it is associated with these conditions: Obesity: This is the most common association. Losing weight can reverse it Genetic disorders: Down syndrome can cause it. Cancers of the digestive tract, liver, kidney, bladder, or lymphoma: This is rare. Polycystic ovary syndrome (PCOS) and ovarian cysts; PCOS is associated with insulin resistance and diabetes. Medications: This includes birth control pills, human growth hormone, high-dose niacin, prednisone, and some other medications. Type 2 diabetes: One 2016 study noted that more than half of children with type 2 diabetes have acanthosis nigricans. Adults with diabetes often develop it as well. Insulin Resistance and Acanthosis Nigricans Insulin resistance is a condition in which the body is resistant to the effects of insulin. Insulin causes glucose to be taken into the body cells to be used for energy. Someone with insulin resistance will require larger amounts of insulin for glucose to be taken into the body tissues. Diagnosis Discuss your skin changes with your healthcare provider, who will examine your skin and can usually diagnose it based on its appearance. Your practitioner may order blood sugar levels or insulin levels. In some cases, endoscopy or X-rays are needed to check for cancer and other causes. Treatment Primary treatment of acanthosis nigricans aims to correct the underlying cause. It is reversible and will disappear as the cause is treated. Weight loss and reversing insulin resistance are the most effective ways to eliminate the skin changes. Topical retinoids increase the shedding of normal skin cells, which can reduce the appearance of the lesions. There are also cosmetic treatment options if acanthosis nigricans is severe or does not improve with weight loss. Treatments include laser therapy, topical retinoids, and dermabrasion. These procedures should only be performed by a certified dermatologist. Frequently Asked Questions What is acanthosis nigricans and what causes it? Acanthosis nigricans are dark patches of thickened, velvety skin. It commonly appears on the neck, thighs, or groin and is often confused at first with dirt-crusted skin. Its exact cause is unknown, but it is associated with obesity, polycystic ovary syndrome, type 2 diabetes, genetic disorders, and certain cancers. You can also have acanthosis nigricans without any other medical conditions. Can you have acanthosis nigricans and not have diabetes? Yes, acanthosis nigricans is more common among people with diabetes than in the general population. However, you can have acanthosis nigricans even if you don't have diabetes. Will acanthosis nigricans go away on its own? If acanthosis nigricans is due to a medical condition, such as diabetes, treating the underlying disease can help clear up dark patches of skin. Weight loss and exercise to reverse insulin resistance can often fade acanthosis nigricans. Should I see a dermatologist for acanthosis nigricans? Yes, a dermatologist can offer specialized treatments for acanthosis nigricans. Treatments include topical retinoids, dermabrasion, or laser therapy. 6 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Kapoor S. Diagnosis and treatment of acanthosis nigricans. Skinmed. 2010;8(3):161-4. American Academy of Dermatology. Acanthosis nigricans: Signs and symptoms. Kota SK, Tripathy PR, Kota SK, Jammula S. Type 2 diabetes mellitus: An unusual association with Down's syndrome. Indian J Hum Genet. 2013;19(3):358-9. doi:10.4103/0971-6866.120818 American Academy of Dermatology. Acanthosis nigricans: Who gets and causes. Bahadursingh S, Mungalsingh C, Seemungal T, Teelucksingh S. Acanthosis nigricans in type 2 diabetes: prevalence, correlates and potential as a simple clinical screening tool - a cross-sectional study in the Caribbean. Diabetol Metab Syndr. 2014;6:77. doi:10.1186/1758-5996-6-77 National Institute of Diabetes and Digestive and Kidney Disease. Insulin resistance and prediabetes. Additional Reading Ng HY. Acanthosis nigricans in obese adolescents: prevalence, impact, and management challenges. Adolesc Health Med Ther. 2017;8:1-10. doi:10.2147/AHMT.S103396 By Nicole Galan, RN Nicole Galan, RN, is a registered nurse and the author of "The Everything Fertility Book." See Our Editorial Process Meet Our Medical Expert Board Share Feedback Was this page helpful? 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