Ever wondered what is causing the darkening of the skin on your neck or armpits? There are many causes of hyperpigmentation on the neck and armpits including everything from dermatitis and psoriasis through to fungal infections and allergic reactions but there are other rare causes and one of these is on the rise in our community.

It is called Acanthosis Nigricans.

What is acanthosis nigricans?
Acanthosis nigricans is an increasingly common condition and we see and treat a lot of it at Chroma Dermatology. It causes hyperpigmentation (darkening of the skin) mainly on the neck and armpits though it can also occur on the face.

Acanthosis is a term that we use to describe thickening of the epidermis (top layer of the skin). The area is raised and velvety. It was first described in 1975, in a landmark study that showed it was an important skin sign of insulin resistance. It is also seen in obese individuals, patients that have polycystic ovarian syndrome and other hormonal conditions, such as acromegaly or Cushing’s disease.

Very rarely, acanthosis nigricans can be seen in an extensive form that can involve skin and even the tongue and oral cavity. But this is a very rare subtype, and it is seen in those patients that actually have malignancies.

What does acanthosis nigricans look like?
Acanthosis nigricans causes velvety darkened areas of skin. It is mainly seen in flexural areas like the neck and the armpits but it can also be seen in the groin and on the face. It is important to recognise it because it is often a sign that there is underlying glucose intolerance/diabetes or possibly hormonal problems.

It may be mistaken for conditions like melasma and post inflammatory hyperpigmentation.

What are the treatments for acanthosis nigricans?
For the common type of acanthosis nigricans, holistic care is important. The dermatologist and general practitioner should work together educate the patient about the importance of diet, exercise, nutrition planning. All these things are critical to improving insulin resistance overall.

Without lifestyle changes, other treatments will not be successful. Keratolytic ingredients (ingredients that exfoliate the skin surface) like salicylic acid and lightening agents like tretinoin and hydroquinone can be used to thin and lighten the affected areas. Picosecond, and in particular, PicoSure laser, can also be tried in treatment resistant cases.

But the key for good skin (and general health!) in this case is carefully selecting meals and exercise plans that will help glucose levels and insulin levels.

The information contained in this blog post is intended as a guide only and should not substitute seeking medical attention. Please see your healthcare provider for more information on suitability of products, treatments or procedures.