Urticaria and hyposideremia: a case report

The authors report the case of an 86-year-old man with a six-month history of chronic idiopathic urticaria, refractory to standard treatments. The patient did not report concomitant diseases and all clinical tests performed were normal. Laboratory tests showed only mild anemia and low serum iron (31 mcg/dl, normal value 59-158). After oral iron supplementation (105 mg/day of elemental iron, taken as ferrous sulphate) for two months, normal serum iron levels and complete remission of urticaria were observed. No further episodes of urticaria were reported at follow-up visits, six and twelve months later. The possible link between hyposideremia and urticaria is also discussed. In vitro experimental data suggest that transferrin inhibits histamine release from mast cells, and a direct correlation exists between the level of transferrin saturation and the degree of inhibition of histamine release. Reduced transferrin saturation due to hyposideremia could lower the threshold of stimulation required for mast cell degranulation, thus increasing the risk of urticaria in response to endogenous and/or exogenous pathogenic stimuli, even minimal. Further studies are necessary to better understand frequency and pathogenic mechanism(s) of “sideropenic urticaria” (chronic urticaria associated with hyposideremia and favourably responding to iron supplementation). From a clinical point of view, evaluation of serum iron levels in selected patients appears advisable, in the light of the relatively low cost and possible significant benefits.