How is Acanthosis nigricans managed?

Management of Acanthosis Nigricans

The management of acanthosis nigricans should focus primarily on treating the underlying cause, with weight reduction being the most effective strategy for obesity-associated acanthosis nigricans. 1

Understanding Acanthosis Nigricans

Acanthosis nigricans (AN) is characterized by symmetric, velvety, hyperpigmented plaques typically found in intertriginous areas such as:

• Neck 1
• Axillae 1
• Inframammary regions 2
• Groin 2

Types and Causes

• Obesity-associated (most common) 3
• Insulin resistance-related 4
• Syndromic 2
• Malignancy-associated 3
• Medication-induced 2
• Acral and unilateral forms 2

Diagnostic Approach

Clinical Examination

• Look for symmetric, hyperpigmented, velvety plaques with ill-defined borders 3
• Assess severity using quantitative scales such as Burke scale 4
• Examine for presence of acne, hirsutism, or clitoromegaly which may suggest PCOS 1

Laboratory Evaluation

• Assess for insulin resistance with fasting glucose or HOMA-IR (Homeostasis Model Assessment-Insulin Resistance) 2
• Screen for type 2 diabetes with fasting glucose followed by a two-hour glucose level after a 75-gram glucose load 1
• Consider thyroid function tests and lipid panel to evaluate for other metabolic disorders 1

Management Strategies

Primary Approach: Treating Underlying Causes

1. Weight Management

   • Weight reduction is the most scientific and practical management strategy 2, 1
   • Target a 7-10% decrease in excess weight for obese patients 1
   • Implement lifestyle modifications including diet and exercise 1

2. Management of Insulin Resistance

   • Consider metformin for patients with insulin resistance 5
   • Rosiglitazone may decrease serum insulin levels but shows inconsistent improvement in AN lesions 5
   • Octreotide has shown improvement in AN, body weight, and glucose/insulin response in some studies 5

3. Address Associated Conditions

   • Discontinue medications that may be causing AN 3
   • Treat underlying endocrinopathies such as PCOS 1
   • Evaluate for malignancy in cases with sudden onset, extensive involvement, or atypical presentation 3

Topical Treatments for Cosmetic Improvement

When underlying causes cannot be fully addressed or for cosmetic concerns:

• Topical retinoids (improve epidermal turnover) 3, 6
• Vitamin D analogs 5
• Keratolytic agents (salicylic acid, urea) 3
• Chemical peels (trichloroacetic acid) 2

Advanced Treatment Options

For severe or resistant cases:

• Oral retinoids for extensive or generalized AN 3
• Laser therapy (Long-pulsed alexandrite, fractional 1550-nm erbium fiber, and CO2 lasers) 2
• Dermabrasion for localized lesions 3

Special Considerations

Acanthosis Nigricans in Children and Adolescents

• AN is increasingly observed in obese children and adolescents 3
• Serves as an early marker for insulin resistance and risk for type 2 diabetes 1
• Distinguishing between type 1 and type 2 diabetes can be challenging in children with AN 1
• Diabetes-associated autoantibodies and ketosis may be present in pediatric patients with features of type 2 diabetes (including obesity and acanthosis nigricans) 1

Acanthosis Nigricans in Skeletal Dysplasia

• In achondroplasia, acanthosis nigricans prevalence is around 10% 1
• Unlike typical AN, in achondroplasia it may be related to FGFR3 variants rather than impaired glucose tolerance 1

Prognosis and Follow-up

• Complete cure and disappearance of lesions are difficult to achieve 2
• Regular follow-up is essential to monitor for metabolic complications 4
• Improvement in AN correlates with improvement in underlying metabolic parameters 5