Cutaneous Leukocytoclastic Vasculitis: The Yield of Direct Immunofluorescence Study
Kanokvalai Kulthanan MD*, Sumruay Pinkaew MSc*, Sukhum Jiamton MD, MSc, PhD, Punkae Mahaisavariya MD*, Puan Suthipinittharm MD*
Affiliation : * Department of Dermatology, Faculty of Medicine, Siriraj Hospital, Mahidol University
Background : Leukocytoclastic vasculitis (LCV) is a clinico-pathological entity. Previous direct immuno-
fluorescence study (DIF) studies of vasculitis showed positive findings mainly in the early stage of the
disease.
Objective : To study the positive yield and patterns of DIF in patients with various stages of LCV.
Design : One hundred patients with LCV who attended the Department of Dermatology, Siriraj Hospital from
1997 to 2000 were enrolled in the study.
Results : The study showed immunoreactive deposits in blood vessel walls in 76 cases(76%). Forty seven per
cent of patients showed immunoreactant deposit only in superficial blood vessel walls, 3% had deposits only
in deep blood vessel walls. Superficial and deep blood vessel wall deposits were seen in 26%. Dermo-
epidermal deposit in addition to blood vessel wall deposit was found in 39%. The most common immunoreactive
deposit was C3 (71%), followed by IgM (35%), IgA (12%) and IgG (8%) respectively. The age of the skin
lesions at the time of biopsy ranged from 1 to 7 days. 82% of patients with one day old lesions showed
immunoreactive deposits in the blood vessel walls and 74% of the group with lesions aged 2-7 days at the
time of biopsy showed immunoreactive deposits in the blood vessel walls.
Conclusion : The present study showed a 76% positive yield for DIF study in patients with LCV when biopsies
were performed within one week of onset. There was a tendency for the percentage of positive DIF results to
decline when the biopsy was performed on lesions that were more than 1 day old.
Keywords : Vasculitis, Immunofluorescence
