Treatment of benign pigmented epidermal lesions by Q-switched ruby laser

Disorders of cutaneous pigmentation are a common problem, which can cause substantial cosmetic morbidity. Traditional treatments are often ineffective and sometimes associated with further hyperpigmentation, hypopigmentation, or scarring. Because the Q-switched ruby laser has proven useful for the treatment of tattoos and, in a small number of cases, benign disorders of the epidermal melanin, we decided to apply this modality systematically to additional benign pigmented lesions.

Thirty-four benign pigmented epidermal lesions including lentigines, café-au-lait macules, and nevi spili in nine white patients were exposed to single pulses of a Q-switched ruby laser (694 nm, 40 ns pulse duration) at 4.5 and/or 7.5 J/cm2.

After one treatment, substantial clearing occurred at each fluence in all lentigines and café-au-lait macules. Initial improvement was achieved in a small nevus spilus after two treatments at 4.5 J/cm2 and a larger nevus spilus after one treatment at 7.5 J/cm2 with complete removal of the junctional or compound nevi portion but no improvement in the café-au-lait portion. Complete return of the background pigment was observed by 1 year. There was no scarring. Immediately after treatment, histology revealed vacuolization of keratinocytes and melanocytes, and occasional subepidermal blisters.

These findings show that while the Q-switched ruby laser may not be entirely useful for treating nevi spili, it does provide an effective treatment for lentigines and café-au-lait macules.