Sex, smell and vasculitis: Henoch-Schönlein purpura in Kallmann's syndrome.

Kallmann's syndrome (KS) is the most common cause of isolated hypogonadotropic hypogonadism. An increased prevalence of rheumatic and autoimmune diseases has been noted in patients with hypogonadism including Kallmann's syndrome. Both in vitro and in vivo studies indicate that testosterone deficiency may promote inflammatory response such as vasculitis by altering inmmunoglobulin and cytokines profiles. We report the novel occurrence of Henoch-Schönlein purpura in a patient with markedly low testosterone level due to Kallmann's syndrome. We discuss the potential mechanisms by which hypoandrogenism may lead to vasculitis.