Equestrian perniosis associated with cold agglutinins: a novel finding.

Reports of equestrian perniosis are rare in the literature and in the cases previously described there have been no abnormal laboratory investigations. We describe two patients with equestrian perniosis who had persistently elevated titres of cold agglutinins. We discuss the relationship of these cold agglutinins to the pathogenesis of perniosis and other related skin disorders.