Adult-onset atopic dermatitis

Abstract

Atopic dermatitis(AD)is an inflammatory skin disease closely related to impairment of skin barrier function. Hereditary factors, life style and exposure to the environment all contribute to the occurrence of AD. Even though AD occurs mostly in infants, sometimes it may initially occur in adults, which is called adult-onset AD(AOAD). There are evident differences in types, immunological mechanisms and association with other diseases between childhood AD and AOAD. The lesional distribution of AOAD is similar to that of childhood AD, while AOAD is characterized by subacute and chronic dermatitis, and mainly manifests as dry hypertrophic lesions rarely complicated with exudation. Th1/Th2 imbalance and hyperfunction of antigen-presenting cells are immunological basis of AD occurrence. Moreover, FLG gene mutations are associated with the occurrence of AD. Acquired expression defect in the FLG gene induced by elevated levels of interleukin-13(IL-13)only occurs in adults, suggesting that AOAD is different from AD that initially occurs during infancy and continues into adulthood. Infection, changes of bacterial flora in the skin and intestinal tract, and smoking are all important causative factors of AOAD, thus enquiries about histories of related diseases and smoking are helpful for the diagnosis of AOAD. Key words: Dermatitis, atopic; Adult-onset atopic dermatitis