II. Epidemiology
- Onset over age 30-40 years
- Most common in Caucasian skin (also seen in asians)
III. Pathophysiology
- Proliferation of basal Melanocytes, increasing melanization in response to Sun Exposure
- Contrast with Freckles which are a result of increased Melanin production
IV. Signs
V. Differential Diagnosis
- Hyperkeratotic lesions (distinguish from the smooth flat surface of Lentigo)- Flat Seborrheic Keratosis
- Pigmented Actinic Keratosis
 
- Lentigo maligna (biopsy if suspected)
- Ephelides (Freckles)
- Cafe Au Lait Macules
- Syndrome with multiple Lentigines- Peutz-Jeghers Syndrome
- LEOPARD Syndrome
- LAMB Syndrome
 
VI. Red Flags (suggesting biopsy)
- Rapid growth
- Lesions suspicious for Melanoma
- Symptomatic lesions- Pain
- Recurrent bleeding
- Poor healing
 
VII. Management
- Light Cryotherapy (<5 seconds) with Liquid Nitrogen- Risk of Hyperpigmentation
- Lesion will disappear for 1 to 3 years
 
- Combination Therapy (effective)- Tri-luma (Hydroquinone 2%, Tretinoin 0.05%, Flucinolone 0.01%)
- Consider combining with light Cryotherapy
 
- 
                          Chemical Peel (recurrence is common)- Trichloroacetic acid (Trichlor) 30-35%
 
- Laser therapy (ND:YAG Laser)
- Bleaching with Hydroquinone (Eldoquin Forte) 3-4%- May result in blotchy Hyperpigmentation (ochronosis) and may take months to see result
- Also risk of acne-type eruption and Hypersensitivity Reaction
 
- Mequinol 2%/Tretinoin 0.01% (Solage) topical solution
- Keratolytics (less evidence than with other methods)
