We are grateful to Sais et al for their interest in and comments on our article. They raise 3 points: (1) the differential diagnosis should include Sweet syndrome; (2) the association of antineutrophil cytoplasmic autoantibodies (ANCAs) with isolated cutaneous leukocytoclastic vasculitis is not unique; and (3) they report work that concludes that perinuclear ANCA (pANCA) is not a marker of systemic vasculitis.
We do not consider Sweet syndrome a valid differential diagnosis in this patient. The clinical appearance of the lesions is far from characteristic, and the histological features have never shown the degree of neutrophilic infiltration seen in Sweet syndrome. The initial report in 1991 of Sweet syndrome occurring with elevated ANCAs1 is in itself controversial2 and has not been noted by any other groups. The histological features in our case are entirely consistent with leukocytoclastic vasculitis as defined at the Chapel Hill Consensus Conference.3 We do not see a role for angiography in the absence of a specific clinical indication in patients with otherwise no evidence of extracutaneous disease. While we agree that the role of ANCA in the pathogenesis of cutaneous and extracutaneous vasculitis merits further investigation, indeed this was the prime reason for reporting this observation, we do believe that our case is quite unique in the literature to date. The only study that has looked at long-term follow-up of similar cases4 showed elevated levels of antimyeloperoxidase autoantibodies to have a strong predictive value for systemic involvement in patients with cutaneous leukocytoclastic vasculitis. The classification of vasculitis remains challenging, but we contend that observation of unusual cases such as ours does offer helpful insights.
Irvine AD, Bruce IN, Walsh MY, Bingham EA. Antineutrophil Cytoplasmic Antibodies in Leukocytoclastic Vasculitis—Reply. Arch Dermatol. 1998;134(2):239-240. doi: