C3 and vasculitis: Regarding the positivity pattern, the present findings are in line with the current literature where C3 is the most common immunoreaction in almost all of the studies.6, 17, 22, 25,26 Although the exact reason for this finding is not known, we can assume that it may be related to the timing of the skin biopsy as immunoglobulins tend to be disappearing faster compared to the complement, and C3 is known to be deposited in relatively later lesions of vasculitis.9, 27