Etiology: Autosomal dominant. Clinical features: Yellowish-brown spots on the face or upper shoulder and other exposed areas, symmetrically distributed. Patients with pale skin tone, mostly before school age and gradually increase with age, the color deepens in summer and lightens in winter. Treatment methods: 1. Intense pulsed light (photorejuvenation): applicable to those with lighter or blurred spots, commonly used for 560~1200 nm wavelength or 530~1100 nm, 550~1100 nm wavelength, Q-regulated ruby laser 694 nm, Q-regulated emerald laser 755 nm wavelength treatment. 2.Laser: Suitable for those with heavy spot color and Chuqing, commonly used Q-modulated-Nd:YAG laser multiplier 532nm wavelength treatment. Treatment effect: Generally, there may be temporary pigmentation for several weeks after surgery, which can be cured by strong pulse light (photorejuvenation) treatment for 1 to 3 times; whereas, it can be cured by laser treatment for 1 time as long as the spots are scanned, and the treatment time is obviously longer than strong pulse light maintenance, and the recurrence degree is lighter than strong pulse light. However, freckles are easy to recur, and sun protection is needed after surgery.