Treatment of Lichen Amyloidosis (LA) and Disseminated Superficial Porokeratosis (DSP) with Frequency-Doubled Q-Switched Nd:YAG Laser

BACKGROUND: Under normal practice, the full thickness of the epidermis is peeled off when treating pigmented lesions with a frequency-doubled Nd:YAG laser. Based on this observation, it is postulated that this laser may be effective for treating lichen amyloidosis (LA) and disseminated superficial porokeratosis (DSP) for which the pathologic changes are limited to the epidermis and papillary dermis. OBJECTIVE: To investigate the clinical effect of frequency-doubled Nd:YAG laser treatment for one patient with LA and for one patient with DSP. METHODS: Frequency-doubled 532 nm Nd:YAG laser pulses were delivered to the lesions on the limbs of a patient with LA and the face and forearms of a patient with DSP. Lesions of LA were treated two or three times, and those of DSP were treated four times, treatment sessions being 1 month apart. For this investigation, biopsies were taken from untreated lesions prior to treatment, lesions immediately after laser treatment, and lesions present at a 9-month follow-up investigation. RESULTS: Both the patient with LA and the patient with DSP responded well to treatment, the results of which remained unchanged at a follow-up conducted 9 months after the final treatment session. CONCLUSION: Frequency-doubled Nd:YAG laser treatment provided excellent results for the patient with LA as for the patient with DSP. The effectiveness of this method deserves further study in a larger group of test patients.