An overview of zinc and its importance in dermatology-Part II: The association of zinc with some dermatologic disorders

In a study on humans and mice with Zn deficiency, Kawamura et al. revealed that allergic contact dermatitis was diminished, whereas irritant contact dermatitis was more severe and prolonged than that in controls.They also proved that epidermal Langerhans cells, which play a protective role against the ATP-mediated inflammatory signals, were decreased in number in humans and mice with the AE under the Zn-deficient diet [3]. Seborrheic dermatitisSeborrheic dermatitis (SD) is a chronic dermatosis affecting sebum-rich areas [6].Its manifestations include flaking and pruritus with underlying inflammation and hyperproliferation [7].In an in vitro study, Guillard et al. showed that a Zn compound named Zn L-cysteat had a significant anti-seborrheic effect [8].In addition, Zn in the form of Zn pyrithione shampoo is effective in treatment of this disease [6].Zn pyrithione can decrease the cell turnover rate in hyperproliferative dermatoses.It also has fungistatic and antimicrobial activities [9].In a comparative study, Shin et al. showed that although the response to betamethasone lotion and tacrolimus ointment was more rapid than zinc pyrithione shampoo, patients treated by Zn pyrithione improved continuously even after cessation of the treatment [6].In a randomized, prospective, parallel-group, investigator-blinded trial conducted by Quadri et al., the efficacy of thermophobic foam Acrodermatitis entropathicaAE is rare congenital form of Zn deficiency [3].The clinical manifestations of this disease usually start following weaning from breast feeding, when the protective effect of the Zn binding ligand from the mother's milk is no longer present [4].They include growth retardation, diarrhea, alopecia, and characteristic cutaneous lesions involving acral, periorificial, and anogenital areas [3][4][5].It appears that the cutaneous lesions in this disorder are caused by apoptosis of keratinocytes, which are easily controlled by Zn supplementations [5].