Persons suffering from of acanthosis nigricans may have a number of underlying causes or diseases. The initial step in the evaluation of acanthosis nigricans must be the identification of the underlying causes.  It is medically recommended that patients undergo certain tests particularly in overweight or obese adults and children who have no previous history of insulin resistance. An adult is deemed overweight when his or her body mass index is 25 kg/m² or more (BMI=weight in kilograms divided by height in meters squared). Children and adolescents are considered overweight when they are at least in the 85th percentile on the gender and age growth chart. They are obese when they exceed the 95th percentile. The tests should focus on blood pressure (BP), fasting glucose as well as fasting lipoprotein profile, hemoglobin A1C, fasting insulin, and ALT (alamine amino transferase). Any unusual findings or abnormalities must be immediately communicated with the health care provider or referred to an endocrinologist.

Obesity is long considered as a major health problem in the United States. Statistics have shown that the prevalence of obesity among Americans have significantly increased over the last three (3) decades. In 2007-2008 alone, the percentage of adults (20 or over) who are obese stands at 34%  while the overweight of the same age group is at 34%. While not a requirement for obesity screening, educating patients about the nature of acanthosis nigricans is a good starting point to introduce treatment for the obese or overweight.

Non-pharmacologic therapy includes basic lifestyle changes which includes a healthier diet and exercise. Pharmacologic management may be needed for patients suffering from the following conditions: hypertension, hypercholesterolemia, hypertriglyceridemia, low levels of high density lipoprotein (HDL), or elevated fasting glucose.

Obviously because acanthosis nigricans also manifests in malignant form, there are certain red flags that should cause a much careful diagnosis. These warning signs can include unexplained weight loss and the rapid progression of an extensive acanthosis nigricans. Patients with malignant complications commonly show signs of mucosal manifestations as well as tripe palms, florid cutaneous papillomatosis, and the sign of Leser-Trélat. Acanthosis nigricans that becomes apparent after the administration of a causative medication should prompt immediate discontinuation, if possible, or changed with an alternative medication.

Acanthosis Nigricans Treatment

According to medical experts, improvement of the skin appearance is primarily the patient’s utmost concern. However, no randomized as well as controlled trials currently exist for any treatment of AN. Nevertheless, medical experts all agree that treating the underlying cause or causes can greatly improve or reverse acanthosis nigricans.

In a medical study, experts compared the effectivity of metformin and rosiglitazone, both insulin sensitizers, in at least 30 overweight Mexicans. In 12 weeks, both medications only demonstrated minimal effects and improvement in their acanthosis nigricans lesions. Still questions remain if the therapy duration was sufficient enough to make the trial conclusive. But a more focused and smaller 6-month trial of metformin in a number of obese patients resulted in a marked improvement of AN in 3 of 5 patients.

Retinoids have also been documented and successfully proven to treat this skin disorder. In at least two (2) cases, the use of topical 0.1 percent tretinoin have been shown to improve the appearance of the skin. An 18-year old woman with AN, the study claims, had her neck cleared of acanthosis nigricans in 10 days and had the appearance and texture of her armpits improved within 2 weeks. In another patient, her left armpit was also cleared of AN in 2 weeks with her daily use of tretinoin 0.1 percent. The right armpit which was used as a control remained affected with the lesion.

Accordingly, in a separate study, experts claimed that it is not only the topical retinoids that can be used to improve AN lesions. Oral retinoids such as isotretinoin and acitretin were also been proven to be beneficial as well. However, to achieve the desired improvement, large doses and extended courses of the oral retinoids are needed. Relapse was also noted once the intake has been discontinued. In the case of one obese woman, her AN improved with isotretinoin taken 3 mg/kg/day but a relapse occured when the medication was stopped. An 18-year old man, who was diagnosed with an idiopathic acanthosis nigricans, had a complete recovery after 45 days of acitretin therapy taken at 0.8 mg/kg (50 mg) divided into two (2) daily doses. Thereafter, he started a 2-month maintenance therapy of 25 mg each day but the lesions came back which subsequently improved with a 0.1 percent topical retinoid intervention. An obese man also saw a 90 percent improvement in his palms and armpit lesions within 2 months of taking 80 mg/day of isotretinoin. He, however, experienced an exacerbation of his skin lesions after tapering his dose over a 1 year period but which improved afterwards with 1000 mg of metformin taken twice daily. Medical experts have warned that for all the benefits it bring, the systemic use of oral retinoids for acanthosis nigricans may be improper considering their side effects and toxic potential.

Published reports also referred to calcipotriol, fish oil, and laser therapy as being useful in improving the skin lesions of patients.

From the numerous anecdotal accounts, it can then be inferred that it is possible to reverse acanthosis nigricans. Nonetheless, given their ease of use, safety, and availability, topical retinoids are thought to be a reasonable choice as a preferred first-line treatment. It remains to be seen, however, if another therapy is equally or more effective than those already mentioned.

Source: http://dermatology.cdlib.org

Filed under: acanthosis nigricans

The eight (8) known types of acanthosis nigricans:

 1. Acral AN (acral acanthotic anomaly) : this type of AN mainly manifest in persons that are otherwise healthy individuals. Accordingly, it is fairly common among individuals of African American descent. Its most prominent characteristic is the hyperkeratotic velvety lesions over the dorsal aspects of the hands and feet.

2. Drug-induced AN, : this type of acanthosis nigricans is the result of certain medications, including nicotinic acid, insulin, pituitary extract, systemic corticosteroids, and diethylstilbestrol. And, though rare, can also be induced by triazinate, oral contraceptives, fusidic acid, and methyltestosterone. The symptoms of drug-induced AN may be reversed once the offending medication is stopped.

3. Familial AN: this is the type of AN that is genetically transmitted. It is a rare genodermatosis and is inherited as an autosomal dominant trait. The lesions typically manifest during early childhood but can begin at any age and the condition may progress until puberty but regresses over time.

4. Malignant AN: this is the type of acanthosis nigricans that is alarming and needs immediate medical attention because the underlying problem is associated with a cancer. The underlying cause here is an internal malignancy.

5. Mixed-type AN: this AN often involves one of the types of acanthosis nigricans where the patient develops a new lesion or symptoms that is of a different cause, like one who has obesity-induced AN who subsequently develops malignant AN.

6. Obesity-associated AN: this AN was once called pseudo-AN and is the most common type of acanthosis nigricans. The lesions for this type can begin to appear at any age but are more prevalent in adulthood. This type is weight dependent, thus the name. Weight can completely reverse the symptoms and the lesions for this type of AN. Insulin resistance is sometimes exhibited by patients falling under this type.

7. Syndromic AN: this type of acanthosis nigricans, as the name suggests, is associated with a syndrome. Aside from insulin resistance which is one of the underlying causes generally associated with acanthosis nigricans, AN has also been linked with other syndromes. Two (2) special examples of these are, the type A and type B syndromes.

• The type A syndrome is also known as the HAIR-AN syndrome which consists of hyperandrogenemia, insulin resistance, and AN syndrome. This syndrome is often hereditary, which affects mainly young women (especially those of African-American descent). It is linked to PCOS (polycystic ovary syndrome) or to signs of virilization (eg, hirsutism, clitoral hypertrophy). Unusually high-levels of plasma testosterone are typical. The lesions of acanthosis nigricans may manifest even in infancy and progresses quickly during puberty.

• On the other hand, the type B syndrome usually develops in women who suffer from an out-of-control diabetes mellitus, ovarian hyperandrogenism, or other autoimmune diseases such as systemic lupus erythematosus, scleroderma, Sjögren syndrome, or Hashimoto thyroiditis. Circulating antibodies to the insulin receptor may be present. Sufferers of this syndrome will usually manifest varying degrees of lesions of AN.

8. The last type of acanthosis nigricans is the Unilateral AN, also occasionally referenced to as nevoid AN. It is medically considered to be genetically transmitted as an autosomal dominant trait. The lesions of this type are unilateral in distribution and becomes visible at the time of infancy, childhood, or adulthood. There is a gradual expansion of the lesions just before it stabilizes or regresses on its own.

Filed under: acanthosis nigricans

Let me start off by saying, Welcome to my humble blog!. I’m not much of a web designer so bear with the “basic” design of my website lol! (props to my equally un-artistic friend who help me get this website finally up and running).

If you happened to find this website you’re probably looking for information about acanthosis nigricans (AN) and if my guess is right, you or one of your loved ones is suffering from this skin condition known as acanthosis nigricans. As you probably know by now, this condition, as defined by medical health authorities, is a skin disorder in which a dark, thick and often velvety skin appears in body folds and creases. These visible skin markings usually manifests in the back of the neck or neck folds, groin, armpits and knuckles.

Known causes, incidence, and risk factors of acanthosis nigricans

Acanthosis nigricans can affect anyone including otherwise healthy people, or it may be associated with certain medical problems. Certain cases are genetically inherited or transmitted. The problem is most generally seen among people of African descent, simply because it is simpler to determine in more dark skin.

Weight problems, often obesity, and some endocrine disorders can result in acanthosis nigricans. It’s more prevalent in individuals with obesity-related diabetes.

In some cases, certain types of drugs specially hormones like the human growth hormone or birth control pills can also cause AN.

Likewise, persons afflicted with lymphona or gastrointestinal or genitourinary tracts cancers are also prone and more like to develop severe cases of this skin disorder.

Symptoms

This skin disorder usually manifests gradually and does not involve any symptoms other than skin changes.

At some point, the visible markings with the dark and velvety skin will start to appear. Folds and creases within the armpits, groin as well as the back of the neck will also appear and in some cases, over the knuckles of the fingers and toes.

In some cases, though less common, the affected areas can also include the lips, palms of the hands, soles of the feet, or some other areas of the body. These affected areas are commonly seen in people with certain types of cancer.

Medical conditions linked with benign AN

According to studies, the most common source or cause of the benign-type of acanthosis nigricans is insulin resistance, a medical condition in which the body does not properly use the insulin that it produces. Insulin resistance is usually a precursor to type-2 diabetes and also one of the known causes of polycystic ovarian syndrome (PCOS) in women.

Acanthosis nigricans can also be found and associated with Hashimoto’s Thyroiditis, Addison’s disease, and hemochromatosis (iron overload, or “bronze” diabetes).

In other cases, AN is trasmitted through heredity (passed on from parent to child). Another known form of AN is the malignant or cancerous AN. Malignant AN though clinically manifests like the the benign-type should be more carefully examined especially if the lesions develop more rapidly, affecting a large area of the body, symptomatic, or are in unnatural locations.

Signs and Tests

Your doctor or health care provider, usually an endocrinologist, can make a diagnosis of acanthosis nigricans simply by looking at your skin. To be sure, a skin biopsy may be ordered especially if unusual symptoms are manifested.

If no clear cause of AN is found, additional tests may be needed. Your doctor may order for blood tests, an endoscopy, or an x-ray in order to eliminate diabetes or cancer as the source of AN.

Prognosis

This skin disorder usually fades if the underlying cause can be found and treated.

Filed under: acanthosis nigricans