What are the common locations for Acanthosis Nigricans?

Acanthosis nigricans is characterized by the appearance of dark, thickened patches of skin with a velvety texture. These patches commonly occur in body folds and creases. The most prominent areas where acanthosis nigricans appears include the neck, armpits, and groin area.

Main Locations of Acanthosis Nigricans

The most common areas for acanthosis nigricans to develop include:

• Armpits: The underarm area is a common site for these dark, thickened skin patches [4].
• Neck: Dark patches often appear on the back or sides of the neck [4].
• Groin: Acanthosis nigricans can develop in the groin area, where skin folds rub against each other [4].

These patches can appear anywhere on the body and are typically dry with a velvety feel [4]. Some individuals may also notice small skin tags (skin growths) on these patches [4].

Causes of Acanthosis Nigricans in These Areas

Acanthosis nigricans is often a sign of an underlying health condition and may be associated with obesity, prediabetes, or certain medications, though it can also appear in otherwise healthy individuals [5]. It can also be linked to conditions affecting hormone levels, such as type 2 diabetes, Cushing's syndrome, polycystic ovary syndrome (PCOS), or hypothyroidism [4]. In some cases, acanthosis nigricans may result from taking specific medications, such as steroids or hormonal treatments like birth control pills [4]. Rarely, acanthosis nigricans can be a sign of cancer, typically stomach cancer in those instances [4].

For more information on the link between acanthosis nigricans and insulin resistance, you can visit Acanthosis Nigricans: Neck and Insulin Resistance (Arabic).

When Should You See a Doctor?

If you notice new dark patches on your skin or any other skin changes that concern you, it is important to consult a general practitioner [4]. Although acanthosis nigricans is often harmless, it is best to have any skin changes examined. In rare cases, it can be a sign of something more serious, such as cancer [4]. A doctor can typically diagnose acanthosis nigricans just by looking at the skin and may recommend certain tests to identify the underlying cause of the patches [4].

Management Options for Acanthosis Nigricans

Treatment for acanthosis nigricans depends on addressing the underlying cause. Once the cause is treated, the patches should fade over time [4]. If the person is significantly overweight, the doctor may recommend weight loss [4]. Depending on the cause, the doctor may also recommend medications to balance hormones or insulin levels, or a change in any medications that may be causing the patches [4]. There is no specific treatment for the patches themselves, but a dermatologist may suggest treatments to improve their appearance, although identifying and treating the cause is usually the primary recommendation [4].

Medical references

• Acanthosis nigricans - NHS
• Abnormally dark or light skin
• Acanthosis nigricans: Who gets and causes