Iron toxicity: new conditions continue to emerge.

During the past half century, excessive/misplaced iron has been observed to be a risk factor for an increasing number and diversity of disease conditions. An extensive list of conditions and of the types of iron association were published in early 2008. Within the subsequent year, four additional disorders have been recognized to be enhanced by iron: aging muscle atrophy, viral replication, rosacea and pulmonary alveolar proteinosis. This paper adds new data and emphasis on these disorders as entities associated with increased iron load and toxicity.