Cutaneous manifestations of pediatric granulomatosis with polyangiitis: a clinicopathologic and immunopathologic analysis.

BACKGROUND: Granulomatosis with polyangiitis (GPA) is a rare systemic vasculitis associated with variable cutaneous manifestations and histopathologic findings. It is less frequent in children than adults and is often positive for cytoplasmic antineutrophil cytoplasmic antibody (ANCA) or proteinase 3-ANCA.

OBJECTIVE: We sought to better define and correlate the clinical, histopathologic, and immunopathologic characteristics of cutaneous GPA in pediatric patients.

METHODS: We retrospectively reviewed clinical records and cutaneous histopathologic specimens of patients 17 years or younger with cutaneous manifestations of GPA who were seen at our institution from 1990 to 2013.

RESULTS: Of the 52 patients identified with GPA, cutaneous involvement occurred in 36.5% and was the initial manifestation of disease in 7.7%. Of the 19 patients with cutaneous involvement, 26.3% developed acneiform and folliculitis-like papules; 84.2% were cytoplasmic ANCA positive; and 78.9% were proteinase 3-ANCA positive. Histopathologic features included leukocytoclastic vasculitis, granulomatous inflammation, acneiform and perifollicular inflammation, granulomatous vasculitis, and palisading granulomas.

LIMITATIONS: Our study was limited because of its retrospective design.

CONCLUSION: Pediatric patients with cutaneous GPA most commonly have palpable purpura, leukocytoclastic vasculitis, and positive cytoplasmic ANCA or proteinase 3-ANCA serologic results. Cutaneous manifestations and histopathologic findings vary, but acneiform lesions may be a cutaneous manifestation of the disease unique to this age group.