F. Milazzo S. Piconi D. Trabattoni C. Magni M. Coen A. Capetti M.L. Fusi C. Parravicini M. Clerici Authors' af®liations: F. Milazzo, S. Piconi, C. Magni, M. Coen, A. Capetti, Divisione di Malattie Infettive, Ospedale L. Sacco, Milan D. Trabattoni, M.L. Fusi, M. Clerici, Cattedra di Immunologia, Universita Á degli Studi di Milano, Padiglione L.I.T.A., Ospedale L. Sacco, Milan C. Parravicini, Cattedra di Anatomia Patologica, Ospedale L. Sacco, Milan, Italy Correspondence to: Mario Clerici, MD Cattedra di Immunologia Padiglione L.I.T.A. Ospedale L. Sacco Via G.B. Grassi 74 20157 Milan Italy Date: Accepted for publication 21 September 1998 To cite this article: Milazzo F., Piconi S., Trabattoni D., Magni C., Coen M., Capetti A., Fusi M.L., Parravicini C. & Clerici M. Intractable pruritus in HIV infection: immunologic characterization. Allergy 1999, 54, 266±272. Copyright # Munksgaard 1999 ISSN 0105-4538 Short communication Intractable pruritus in HIV infection: immunologic characterization Severe pruritus unresponsive to symptomatic treatment and appearing in nonatopic patients is a relatively common feature of advanced HIV infection. Alterations in the number of eosinophils can cause pruritus, and these two conditions are often associated (1±5) in this disease. Augmented serum concentrations of IgE may also be observed in HIV-infected patients (6) and hyper-IgE appear- Key words: cytokines; dermatology; HIV; IgE; immunology; pruritus. Background: Severe, intractable pruritus, often associated with erythematopapular skin lesions and hypereosinophilia, is a condition observed in some nonatopic, HIV-infected patients. We performed immunovirologic analyses of this condition. Methods: Immunologic (mitogen-stimulated production of cyto- kines, tumor necrosis factor-alpha [TNF-a], and soluble CD23; serum levels of soluble CD23, ICAM-1, TNF-a, IgG, IgE, and IgA) and virologic (HIV viral load) parameters were analyzed in six patients with therapy-resistant pruritus. Hypereosinophilia was present in all these patients. Results were compared to those of seven HIV-seropositive individuals similar to the ®rst one in terms of CD4 counts and clinical staging, but without pruritus. Results: Hypereosinophilia; hyper-IgE and hyper-IgA; augmented interleukin (IL)-4, IL-5, and sCD23; and reduced interferon- gamma production by mitogen-stimulated peripheral blood mononuclear cells (PBMC) were detected when patients with pruritus were compared to HIV controls. HIV viral load was also augmented in patients in whom pruritus was present. Conclusions: The results suggest that therapy-resistant, intract- able pruritus accompanied by hypereosinophilia may be used to de®ne a subset of HIV-seropositive individuals showing proto- typic hyperactivation of humoral immunity, and in whom augmented HIV viral load is present. 266