The topical immunomodulator tacrolimus ['Protopic'] has been shown to be effective and well tolerated in its approved indication, the second-line treatment of moderate-to-severe atopic dermatitis, in a number of clinical studies. As atopic dermatitis is a chronic condition, the effects of long-term treatment with agents such as tacrolimus are of considerable interest. Results from two studies involving more than 8000 adult and paediatric patients with moderate-to-severe atopic dermatitis, presented at the 61st Annual Meeting of the American Academy of Dermatology (AAD)[San Francisco, US; March 2003], showed that long-term intermittent treatment with topical tacrolimus was effective and well tolerated. In these studies, tacrolimus 0.1% ointment continued to provide improvements in atopic dermatitis over treatment periods of up to 4 years. Furthermore, the long-term adverse events profile was equivalent to that observed in studies of shorter duration. Importantly, the incidence of skin infections was not significantly different from that generally observed in patients with atopic dermatitis, and none of the patients in either study experienced skin atrophy, an adverse event commonly associated with prolonged use of topical corticosteroids. Another study presented at the meeting indicated that topical tacrolimus is also effective and well tolerated in patients with less severe dermatitis.