Conflict of interest: none declared.
Clinical dermatology •Concise report
Cutaneous vasculitis and glomerulonephritis associated with C4 deficiency
Article first published online: 18 JUN 2013
© 2013 British Association of Dermatologists
Clinical and Experimental Dermatology
Volume 38, Issue 5, pages 492–495, July 2013
How to Cite
Kosaka, S., Osada, S., Kaneko, T., Nishimura, S. and Kawana, S. (2013), Cutaneous vasculitis and glomerulonephritis associated with C4 deficiency. Clinical and Experimental Dermatology, 38: 492–495. doi: 10.1111/j.1365-2230.2012.04423.x
- Issue published online: 18 JUN 2013
- Article first published online: 18 JUN 2013
- Accepted for publication 11 March 2012
Complete deficiency of the fourth component of complement (C4) is an extremely rare condition. However, it has been reported that partial C4 deficiency can occur in normal subjects, and is associated with several immune diseases. We report a 44-year-old woman who developed slight oedema and punctate purpura on her lower legs after a common cold. She was noted to have persistent microscopic haematuria and proteinuria, and her C4 level was undetectable. On histological examination of a skin biopsy specimen, leucocytoclastic vasculitis was seen, with granular deposition of IgG, IgM, C3 and C1q on the vessel walls in the upper dermis. A renal biopsy showed mild mesangial proliferative glomerulonephritis with slight damage to the capillary loops, and granular deposits of IgM and C4 mainly in the mesangium. The patient was systemically well and needed no medication. The C4 level remained low during the observation period, but neither genotyping nor allotyping analysis identified a C4 deficiency.