Sparing phenomenon of cutaneous small-vessel vasculitis around solar lentigines and peripheral halo.

: SUKAKUL SPARING PHENOMENON OF CUTANEOUS SMALL-VESSEL VASCULITIS AROUND SOLAR LENTIGINES AND PERIPHERAL HALO. This is a case presented with biopsy-confirmed diagnosis of cutaneous small-vessel vasculitis sparing solar lentigines and peripheral normal skin called "halo effect". A 69-year-old healthy Thai male presented with asymptomatic, slowly progressed solar or senile lentigines for more than 10 years with new emerging rashes on legs which were diagnosed as cutaneous vasculitis by clinical and skin biopsy, appeared around halo area adjacent to solar lentigines. Recently, many types of sparing phenomena in dermatology have been reported, but there is no report of this unusual presentation of sparing phenomenon of cutaneous vasculitis in lentigines. However, the pathogenesis still remains unknown, probably related to immunological mechanisms between these 2 conditions which need further studies to identify the cause.