Approximately 10-20% of infants in industrialized countries experience
atopic dermatitis. In recent decades topical
corticosteroids have been the first-choice
therapy for treatment of flares. However, this form of
therapy may induce skin
atrophy, especially after application to facial lesions or with long-term use. Thus, development of new anti-inflammatory topical agents for the treatment of childhood
atopic dermatitis was needed. The topical
calcineurin inhibitors tacrolimus and
pimecrolimus have an effect on various cells of the cutaneous immune system, specifically on T cells, by inhibiting the
phosphatase calcineurin and preventing the transcription of proinflammatory
cytokines. In several clinical studies of children and adults with
atopic dermatitis, topical
calcineurin inhibitors were found to be effective both on the face and the trunk and extremities, in both short- and long-term treatment regimens. Tachyphylaxis or rebound were not observed. In most patients an improvement of their
eczema occurred during the first week of treatment, as measured by subjective and objective clinical signs of
atopic dermatitis. Treatment significantly reduced the incidence of flares and the need for
corticosteroids in children and adults. Treatment success, commonly defined as 'excellent improvement' or 'clearing of all lesions', was observed in more than one-third of all children treated with 0.03% or 0.1%
tacrolimus or 1%
pimecrolimus. Topical application of
pimecrolimus and
tacrolimus does not lead to significant blood concentrations of these agents in the majority of children with
atopic dermatitis, and any increase in blood concentrations decreases after a few days of
therapy. No changes in laboratory parameters were observed in short- and long-term studies in patients with
atopic dermatitis. The most common adverse effect following the application of topical
calcineurin inhibitors is mild to moderate symptoms of irritation such as burning,
erythema and
pruritus, which occurred in up to 20% of all children treated with
tacrolimus and 10% of children treated with
pimecrolimus, and usually faded after a few days. In contrast to topical
corticosteroids,
calcineurin inhibitors do not induce skin
atrophy, even after long-term use. Topical
calcineurin inhibitors have been proven to be effective and have a good safety profile during short-term and long-term use for up to 1 year with
pimecrolimus and up to 4 years with
tacrolimus. Given the lack of extensive experience with use of topical
calcineurin inhibitors over longer periods, regular use of these agents, particularly in children, should be undertaken only after careful consideration of individual cases. Sun protection should also be advised.