Histopathologic differences between cutaneous vasculitis associated with severe bacterial infection and cutaneous vasculitis secondary to other causes: study of 52 patients.

OBJECTIVES: To determine if cutaneous vasculitis (CV) associated with severe infection has some histopathologic findings that may help us to differentiate patients with this condition from other patients with CV.

METHODS: We reviewed the skin biopsy specimens of patients with leukocytoclastic CV associated with a severe bacterial infection. Histopathologic findings of these patients were compared with those observed in leukocytoclastic CV secondary to other causes. Biopsy-proven leukocytoclastic CV were stratified as follows: group a): CV associated with severe underlying bacterial infection; group b): CV without severe bacterial infection but with systemic involvement; group c): CV without systemic involvement. Slides were reviewed by expert pathologists that were blind to the clinical information. The severity of vascular lesions was measured according to a semiquantitative scale (Hodge index). A comparative study between group a) and the other groups was conducted.

RESULTS: group a) included 12 patients (2 women/10 men), mean age± SD 56±15 years; group b) 21 patients (10 women/11 men), 52±18 years; and group c) 19 patients (12 women/7 men), 59±24 years. Presence of neutrophilia was significantly increased in biopsies from group a) when compared with the other two groups. Also, a trend to higher frequency of pustular dermatosis was found in patients from group a). Hodge index, degree of inflammatory infiltrate and deep arterioles involvement were similar in all groups.

CONCLUSIONS: Neutrophilia is common in skin biopsies of patients with CV associated with severe bacterial infection. No other histopathological findings help us to establish the presence of a severe underlying infection.