An Acanthosis Nigricans

Acanthosis nigricans is a disease that causes dark, thickareas on the skin. The areas affected are spread out, and the skin isvelvety. It is most common in the armpits and other body folds.

What is going on in the body?

There are four types of acanthosis nigricans.

Gougerot-Carteaud syndrome occurs in young females and is probablyinherited.

Malignant acanthosis nigricans is sometimes seen in adults withcancer of the genital, urinary, or gastrointestinal systems.

Miescher syndrome is an inherited disease that causes skin lesionsfor no apparent reason.

Pseudoacanthosis nigricans is caused by a hormone imbalance in thebody that may cause excess insulin in the blood.

What are the causes and risks of the disease?

There are many causes of acanthosis nigricans, including thefollowing:

Addison disease,which is caused by a deficiency of hormones from the adrenal gland

diabetes

disorders of the pituitary gland within the brain

genetic causes

growth hormone therapy

hypothyroidism,which means low levels of thyroid hormone that are caused by decreased activity of thethyroid gland

insulin resistance caused by obesity

oral contraceptives

some medicines, such as nicotinic acid, which are used to treathigh cholesterol

What are the signs and symptoms of the disease?

Acanthosis nigricans causes skin lesions that are darkerthan the skin around them. The lesions have a velvety feel. Thelesions often form in the folds along the neck, armpits, groin, knuckles,between the legs, at the elbow, under the breasts, and around the bellybutton.

How is the disease diagnosed?

A doctor can diagnose acanthosis nigricans by doing amedical history and physical exam.

What can be done to prevent the disease?

When acanthosis nigricans is caused byobesity,weight management is key. When it is caused bycancer,there may be little that can be done to prevent it until the cancer issuccessfully treated. Acanthosis nigricans caused by medicine maygo away once the medicine is stopped.

What are the long-term effects of the disease?

A person with acanthosis nigricans may have chafing of theskin. These areas do not become cancerous. The appearance ofthese chafed spots bothers some people.

What are the risks to others?

Acanthosis nigricans is not catching and poses norisk to others.

What are the treatments for the disease?

Treatments of acanthosis nigricans include the following:

antibiotic ointments or creams

retinoids, taken orally or used in a cream

topical corticosteroid creams

weight lossto lower insulin resistance

What are the side effects of the treatments?

Side effects of steroid creams and ointments include stretchmarks and thinning of the skin. Retinoids can cause birth defects if takenby a pregnant woman.

What happens after treatment for the disease?

The doctor may recommend treatment for an underlyingcondition or disease. For example, obesepeople may be advised to lose weight to lower their insulin resistance. Aperson who has diabeteswill need to keep blood glucose levels under good control.

How is the disease monitored?

The disease or condition that is causing acanthosis nigricanswill need to be monitored. Any new or worsening symptoms should bereported to the doctor.