Necrotizing herpes zoster mimicking relapse of vasculitis in angioimmunoblastic lymphadenopathy with dysproteinaemia.

An 81-year-old man presented with a generalized maculopapular rash, lymphadenopathy, conjunctivitis and arthritis. Vasculitis was confirmed by skin biopsy and by direct immunofluorescence, which showed perivascular C3 and granular IgM accumulation. Histology of an inguinal lymph node was diagnostic for angioimmunoblastic lymphadenopathy with dysproteinaemia (AILD), and this was confirmed by the finding of hypergammaglobulinaemia and elevated IgE levels. Immunohistology on a lymph node biopsy showed a T-helper cell (CD4) infiltrate expressing the interleukin (IL)-2 receptor alpha and beta chains. While receiving prednisone 100 mg/day, the patient developed new lesions, mimicking a relapse of vasculitis, which were subsequently shown to be necrotizing herpes zoster. Serum IL-2 and IL-6 levels were elevated. To our knowledge, this is the first report of simultaneous elevation of IL-2 and IL-6 in AILD: IL-2 may be involved in proliferation of the malignant cell clone, and IL-6 in the pathogenesis of both the vasculitis (via endothelial cell activation) and the hypergammaglobulinaemia.