A study of the efficacy of carbon dioxide and pigment-specific lasers in the treatment of medium-sized congenital melanocytic naevi.

Background: Treatment of medium-sized congenital melanocytic naevi (CMN) can be challenging.

Objective: To present the results of treatment of 55 CMN with the carbon dioxide (CO(2) ) and pigment-specific lasers.

Methods: CO(2) and Q-switched lasers (frequency-doubled Nd:YAG, Nd:YAG and alexandrite) were used to treat 55 CMN. Patients were treated at 3-month intervals until maximum clearance. Clinical response at 3-6 months after final treatment was graded as poor (< 50%), good (50-75%) or excellent (> 75%). Outcomes were evaluated on case note review and questionnaire.

Results: Thirty-six of the 55 CMN were macular and 19 were mammillated. Twenty-seven CMN were present on the head and neck. For macular CMN, outcomes were better for truncal CMN. Scarring and pallor were seen in three lower limb macular CMN treated with a CO(2) laser. Mammillated CMN on the head and neck showed most improvement. Pigment-specific lasers were of no additional benefit. Repigmentation occurred in 6% of macular and 21% of mammillated CMN. Partial or complete regimentation of CMN was reported by 46% of patients.

Conclusions: Compared with macular CMN, mammillated CMN show a marginally better response to laser treatment. CMN on the limbs respond poorly. Pigment-specific lasers do not lighten mammillated CMN. Adverse effects can occur with CO(2) laser treatment of macular CMN on lower limbs.