LNSLNS We thank Vent and Hüttenbrink for their comments from an otorhinolaryngological perspective. Their letter underlines the interdisciplinary challenge posed by treating patients with this type of systemic vasculitis. The questions asked by Barz provide us with an opportunity to point out again that HUVS is -undoubtedly an independent disease entity. The hypocomplementemia is not specific. Leukocytoclastic vasculitis—not identical with immunovasculitis—is always accompanied by complement deficiency and often by hypocomplementemia. The main symptom that is typical for this systemic vasculitis of the small vasculature is chronic urticarial vasculitis characterized by the immunological marker of the C1q antibody and accompanying complement deficiency. According to the classification criteria for HUVS as set out by Schartz (2), Lupus erythematodes and cryoglobulinemia have to be excluded because for both disorders, similar clinical and immunological constellations have been observed.

Whether hypocomplementemia may exist before onset of HUVS is not known, but is not to be expected either, because in patients in remission, the measured complement concentrations are normal (authors’ own observations). Of course, a multitude of medications may trigger vasculitis (3). Whether medications can trigger HUVS could not be confirmed on the basis of our case patient. As we mentioned in our case report, therapeutic attempts using topical triamcinolone or oral prednisolone remained unsuccessful, as was stopping the ACE inhibitor that the patient had taken for many years. Only immunosuppressive treatment with mycophenolate led to long term remission.
DOI: 10.3238/arztebl.2010.0349c

Dr. med. Martin W. Baumgärtel
Medizinische Klinik, St. Franziskus Hospital
Hohenzollernring 72, 48145 Münster, Germany
Martin.Baumgaertel@sfh-muenster.de

Prof. Dr. med. Wolfgang Grotz
Klinik für Innere Medizin II/Nephrologie, Alfried Krupp Krankenhaus
Alfried-Krupp-Str. 21, 45131 Essen, Germany

Conflict of interest statement
The authors of all letters declare that no conflict of interest exists according to the guidelines of the International Committee of Medical Journal Editors.
1.
Grotz W, Baba HA, Becker JU, Baumgärtel MW: Hypocomplementemic urticarial vasculitis syndrome—an interdisciplinary challenge. [Hypokomplementämisches Urtikaria-Vaskulitis-Syndrom – Eine interdisziplinäre Herausforderung]. Dtsch Arztebl Int 2009; 106: 756–63. VOLLTEXT
2.
Schwartz HR, Mc Duffie FC, Black LF, Schroeter AL, Conn DL: Hypocomplementemic urticarial vasculitis: association with chronic obstructive pulmonary disease. Mayo Clin Proc 1982; 57: 231–38.
3.
Wiik A: Drug-induced vasculitis. Curr Opin Rheumatol 2008; 20(1): 35–9. MEDLINE
1. Grotz W, Baba HA, Becker JU, Baumgärtel MW: Hypocomplementemic urticarial vasculitis syndrome—an interdisciplinary challenge. [Hypokomplementämisches Urtikaria-Vaskulitis-Syndrom – Eine interdisziplinäre Herausforderung]. Dtsch Arztebl Int 2009; 106: 756–63. VOLLTEXT
2. Schwartz HR, Mc Duffie FC, Black LF, Schroeter AL, Conn DL: Hypocomplementemic urticarial vasculitis: association with chronic obstructive pulmonary disease. Mayo Clin Proc 1982; 57: 231–38.
3. Wiik A: Drug-induced vasculitis. Curr Opin Rheumatol 2008; 20(1): 35–9. MEDLINE