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.