Treatment of Acanthosis Nigricans
The primary treatment for acanthosis nigricans should focus on addressing the underlying cause, particularly insulin resistance and obesity, while topical retinoids and keratolytics can be used for cosmetic improvement of skin lesions.
Understanding Acanthosis Nigricans (AN)
- Acanthosis nigricans presents as symmetric, hyperpigmented, velvety plaques with ill-defined borders, typically involving intertriginous areas such as the neck, axillae, groin, and other skin folds 1
- Early recognition is important as AN can be a cutaneous manifestation of various systemic disorders including obesity, insulin resistance, metabolic syndrome, type 2 diabetes, and rarely, internal malignancy 1, 2
Treatment Approach
Address Underlying Causes
- Weight reduction is the most effective and practical management strategy for obesity-associated AN 2
- Treatment of underlying endocrinopathies (such as insulin resistance, diabetes) should be prioritized 1
- Discontinuation of causative medications if drug-induced AN is suspected 1
- Evaluation and treatment of any underlying malignancy in cases of malignant AN 1
Topical Treatments for Cosmetic Improvement
- Topical retinoids (0.05% tretinoin cream) are first-line agents that help reduce hyperkeratosis and hyperpigmentation 1, 2
- Vitamin D analogs can improve skin appearance by normalizing keratinocyte differentiation 2
- Keratolytic agents such as salicylic acid, urea, or ammonium lactate (12%) help remove hyperkeratotic skin 2, 3
- Combination therapy with 12% ammonium lactate cream and 0.05% tretinoin cream has shown success in treating obesity-associated AN 3
Other Treatment Options
- Chemical peels (particularly trichloroacetic acid) may be considered for resistant cases 2
- Laser therapy options include long-pulsed alexandrite laser, fractional 1550-nm erbium fiber laser, and CO2 laser for severe or resistant cases 2
- Oral retinoids may be considered for extensive or generalized AN that is unresponsive to topical therapy 1
- Insulin sensitizers (like metformin) may help improve both the underlying insulin resistance and the cutaneous manifestations 2
Special Considerations
- For insulin-induced AN at injection sites, rotating injection sites and avoiding affected areas is recommended 4
- Improvement in AN lesions may take several months even with appropriate treatment 4
- Complete cure of AN is difficult to achieve, and patients should be counseled about realistic expectations 1, 2
- For periocular AN, careful application of topical agents is necessary to avoid eye irritation 5
- For AN on the hands and forearms, longer courses of topical therapy may be needed due to thicker skin 5
Treatment Monitoring
- Regular follow-up to assess improvement in skin lesions 1
- Monitor for improvement in underlying metabolic parameters (insulin resistance, glycemic control) 2
- Assess for side effects of topical treatments, which may include skin irritation, erythema, and dryness 2
- Consider alternative or additional treatments if no improvement is seen after 2-3 months of therapy 6