LAUSR

839 relapses were observed over a period of more than one year after CO2 laser treatment. In the present case, a CO2 surgical laser was used to irradiate both the HKPs and the surrounding area to a depth just under the basal layer, suggesting that the surgical laser may have depleted the sensory neurons that had invaded the epidermis. The nerve fibres that reach the epidermis are mainly C-fibres, not A-fibres [7]. Sensory C-fibres play an important role in the neuronal transmission of itch [8]. Therefore, in LA, the elongated fibres involved in the increased cutaneous sensory sensitivity and the induction of itching may be C-fibres. A previous report showed that the CO2 laser affects C-fibres [9]. Taken together, the depletion of the diseased epidermis by surgical laser treatment may improve the increased cutaneous sensory sensitivity and itch in LA patients. Interestingly, the CO2 surgical laser treatment also reduces the number of cutaneous mast cells [10]. The effect of the surgical laser on mast cells could also play a role in the improvement of itching. In summary, these results suggest that the treatment of refractory LA with a CO2 surgical laser mounted with a computerised scanner is useful for both improving HKPs as well as the associated itching, which is linked to increased cutaneous sensory sensitivity.