Laser therapy of freckles and lentigines with quasi-continuous, frequency-doubled, Nd:YAG (532 nm) laser in Fitzpatrick skin type IV: A 24-month follow-up

BACKGROUND: Newly developed lasers produce excellent results with minimal complications compared with traditional treatments for freckles and lentigines. OBJECTIVES: To assess the efficacy and safety of the frequency-doubled Nd:YAG (532nm) laser in the treatment of freckles and lentigines in type IV skin. PATIENTS AND METHODS: Twenty adult patients (14 with freckles and six with lentigines) were subjected to a variable number of treatments with a minimum 4-week interval until no additional improvement occurred or >75% improvement was obvious. Patients manifesting >50% improvement were followed up once every 3 months for 24 months. The rest were regarded as treatment failures and not followed up. RESULTS: Sixteen (80%) of 20 patients (freckles, n=10; lentigines, n=6) manifested more than 50% improvement. They were irradiated between three and eight times with a 4-12-week interval. Complications included hypopigmentation (25%), mild textural changes (15%) and hyperpigmentation (10%). All these were mild and resolved within 2-6 months. Of 10 patients with freckles followed up for 24 months, four (40%) patients showed partial recurrence. However, all the patients maintained >50% improvement. None of the patients with lentigines showed recurrence. CONCLUSION: The quasi-continuous, frequency-doubled Nd:YAG (532nm) laser safely and effectively treats freckles and lentigines in Fitzpatrick skin type IV.