Acral Acanthosis Nigricans (AAN) is a rare form of acanthosis nigricans, primarily affecting the dorsal surfaces of the hands, feet, fingers, and toes. It is typically benign and not associated with internal malignancy or insulin resistance, unlike some other types.
Causes of Acral Acanthosis Nigricans
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Genetic factors (especially in darker-skinned individuals)
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Benign condition often without underlying disease
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Sometimes associated with endocrine disorders (less commonly than other forms)
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Rarely, can be a sign of malignancy in elderly patients, but this is very uncommon for acral type
Treatment Options
Treatment is focused on cosmetic improvement and underlying cause (if any).
1. Topical Treatments
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Keratolytics: Help exfoliate the skin
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Examples: Salicylic acid, urea cream (10–20%), lactic acid
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Retinoids: Promote cell turnover and lighten pigmentation
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Examples: Tretinoin cream
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Topical corticosteroids (if inflammation is present)
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Skin-lightening agents:
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Hydroquinone (used cautiously and short-term)
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2. Oral Treatments (only in severe or resistant cases)
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Oral retinoids (e.g., isotretinoin): May help reduce thickening, but with side effects
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Metformin: Sometimes used if there’s insulin resistance (though rare in AAN)
3. Procedures
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Laser therapy (e.g., fractional CO₂ or Nd:YAG laser): May reduce thickened skin
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Dermabrasion or chemical peels: Occasionally used by dermatologists
Investigations (if necessary)
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Usually no extensive investigation is needed unless other symptoms suggest:
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Diabetes
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Thyroid disease
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Polycystic ovarian syndrome (PCOS)
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Internal malignancy (in older patients or sudden onset)
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Lifestyle and Supportive Measures
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Regular moisturizing to reduce dryness and improve skin texture
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Avoidance of irritants
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Sun protection (helps with pigmentation issues)
When to See a Doctor
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If the condition appears suddenly
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If associated with rapid progression, weight loss, or other systemic symptoms
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If there’s significant cosmetic concern