What is the treatment for nigricans acanthosis?

Treatment for Acanthosis Nigricans

The most effective treatment for acanthosis nigricans is addressing the underlying cause, with weight reduction being the primary approach for obesity-associated acanthosis nigricans, which is the most common form.

Understanding Acanthosis Nigricans

Acanthosis nigricans (AN) is characterized by symmetric, velvety, hyperpigmented plaques typically found in intertriginous areas such as the neck, axilla, groin, and inframammary regions. It is most commonly associated with insulin resistance and obesity, but can also be related to other conditions.

Types of Acanthosis Nigricans:

• Obesity-associated (most common)
• Insulin resistance-associated
• Syndromic
• Malignant
• Medication-induced
• Acral
• Unilateral
• Mixed-type

Diagnostic Evaluation

Before initiating treatment, proper evaluation is essential:

1. Screening tests for patients with acanthosis nigricans 1:

   • Fasting plasma glucose
   • 2-hour glucose tolerance test
   • Hemoglobin A1C
   • Fasting lipid panel
   • Insulin levels

2. Additional testing for specific populations:

   • For females with menstrual irregularities: Total testosterone or bioavailable/free testosterone and sex hormone binding globulin
   • Thyroid-stimulating hormone (TSH)

3. Follow-up testing:

   • If initial screening is normal, repeat testing at minimum 3-year intervals or more frequently if BMI is increasing 1

Treatment Algorithm

First-Line Approach:

1. Address the underlying cause:

   • Weight reduction for obesity-associated AN 2, 3
   • Discontinuation of causative medications
   • Treatment of underlying endocrinopathies
   • Treatment of malignancy (if present)

2. Topical treatments for cosmetic improvement:

   • Topical retinoids (first-line therapy) 4
   • Vitamin D analogs (calcipotriol) 3
   • Keratolytics (salicylic acid, urea)
   • Combination therapies to reduce irritation 4

Second-Line Approaches:

1. Systemic medications:

   • Metformin for insulin resistance 3
   • Oral retinoids for extensive or resistant cases 5
   • Octreotide in selected cases 3

2. Procedural treatments:

   • Chemical peels (trichloroacetic acid) 6, 5
   • Laser therapy (Long pulsed alexandrite, fractional 1550-nm erbium fiber, CO2) 6
   • Dermabrasion for resistant cases 5

Special Considerations

For Obesity-Associated AN:

• Focus on lifestyle modifications including diet and exercise
• Target 7-10% decrease in excess weight 2
• Monitor for metabolic abnormalities, as acanthosis nigricans can be a marker for insulin resistance

For Diabetes-Associated AN:

• Optimize glycemic control
• Consider metformin as it addresses both diabetes and may improve AN 3

For Adolescents:

• Screen for prediabetes or diabetes using appropriate tests 2
• Implement lifestyle interventions based on a chronic care model 2
• Provide comprehensive diabetes self-management education if diabetes is present

Treatment Challenges

• Complete resolution of AN is difficult to achieve 6, 5
• Treatment response may be slow and partial
• Recurrence is common if the underlying cause persists
• Topical treatments may cause skin irritation, requiring careful management

Monitoring and Follow-up

• Regular follow-up to assess treatment response
• Monitor for metabolic abnormalities even if initial screening is normal
• If initial screening is normal, repeat testing at minimum 3-year intervals or more frequently if BMI increases 1

Remember that while cosmetic improvement is important for quality of life, addressing the underlying metabolic abnormalities is crucial for reducing morbidity and mortality associated with conditions linked to acanthosis nigricans.