Adverse effects following Q-switched ruby laser treatment of pigmented lesions.

A retrospective study was conducted to investigate the incidence of adverse effects following Q-switched ruby laser treatment of pigmented lesions at the Wessex Specialist Laser Centre. Sixty-one patients received a total of 151 treatments between January 2006 and January 2008. This is the largest series to date of patients on whom adverse effects have been reported following Q-switched ruby laser treatment of an assortment of pigmented lesions. Patients with traumatic or decorative tattoos were excluded from this study. Two of the treatments (1.3%) resulted in adverse effects. One patient developed hyperpigmentation and the other experienced scabbing and subsequent textural change following abrasion of the scab. No predisposing medical or other factors were observed in either patient. This low incidence of adverse effects is consistent with the highly selective absorption of ruby laser light by melanin. The presence of these adverse effects highlights the importance of test patch treatments, the necessity for patients to follow good post-treatment advice and the case for vigilance in monitoring the quality of the laser output.