Atopic dermatitis (AD) is a chronic inflammatory skin disease characte
rized by intensely pruritic subacute and chronic eczematous plaques, t
he pathogenesis of which appears to involve a complex interplay of gen
etic, pharmacological, environmental and psychological factors. Here,
Markus Grewe and colleagues propose that the development of skin lesio
ns in AD patients results from sequential activation of T helper 2 (Th
2)- and Th1-type cells.