Iron deficiency: structural and microchemical changes in hair, nails, and skin

Deficiency of nutritional iron represents a public health problem recognized throughout much of the world. The overall prevalence rate of patients with iron deficiency (ID) who need supplementary iron therapy ranges markedly from less than 10% to as high as 70% among various ethnic and socioeconomic groups. Dermatologically, the iron-deficit state can be a secondary condition or trigger a wide range of mucocutaneous alterations. Early appreciation of adverse cutaneous manifestations of ID seems to have commensurate significance not only in predicting the presence of undiagnosed ID, but also for providing specified avenues for rational therapeutic approaches to patients with ID. Dermatopathic anemia has attracted the attention of clinicians because ID was found to be a metabolic consequence of skin diseases such as erythroderma, exfoliative dermatitis, psoriasis, eczema, and many others. Previous studies had suggested that iron may be lost in accelerated turnover of the keratinocyte from scaling; currently, malabsorption of iron is accepted implication accounting for dermatopathic anemia. However, mucocutaneous affections adversely manifested by ID have not been extensively reviewed and published in the current dermatologic literature because of the potentially benign course of the adverse conditions and the limited degree of clinical expression. Therefore, changes in hair, nails, mucosa and tongue, pruritus, chronically sustained inflammation, dermatitis herpetiformis, and photodermatitis are among the adverse cutaneous sequelae whose relation to ID are highlighted and discussed in the present review. Because of their clinical and diagnostic importance, other extracutaneous physical signs of ID, such as blue sclerae and pica, are also included in this review.(ABSTRACT TRUNCATED AT 250 WORDS)