Treatment of cafe au lait macules with lasers. A clinicopathologic correlation.

BACKGROUND: Cafe au lait macules (CALMs) respond variably to treatment with different lasers. This study was done to determine whether the type of laser and the individual histologic features of the CALMs could predict clinical response to treatment. Nine CALMs were treated with both the frequency-doubled Q-switched neodymium: YAG laser (wavelength, 532 nm; beam diameter, 2.0 mm) and the Q-switched ruby laser (wavelength, 694 nm; beam diameter, 5.0 mm). Both lasers were used at a fluence of 6.0 J/cm2. Biopsy specimens of the CALMs were obtained before and after treatment. Clinical follow-up was done at 1-, 3-, and 6-month intervals. OBSERVATIONS: Both lasers yielded variable responses to treatment. Two histologic subtypes of CALMs were identified, but these different subtypes did not predict clinical outcome after laser treatment. CONCLUSIONS: Cafe au lait macules respond variably to treatment with both the Q-switched ruby laser and the frequency-doubled Q-switched neodymium:YAG laser. Further research might address the effect of using multiple treatments. In view of these results, clinicians using lasers to treat CALMs should inform their patients of the potential for recurrence or darkening of CALMs.