Background  Tacrolimus ointment is effective for treatment of moderate to severe atopic dermatitis (AD) in children aged ≥2 years (Br J Dermatol, 2004; 150: 554). Here, efficacy and tolerability of tacrolimus 0.03% ointment were evaluated in 50 infants aged <2 years at start of treatment.

Methods  Infants with AD previously enrolled in a tacrolimus ointment pharmacokinetics trial were eligible for a 24‐month open‐label phase II study. Tacrolimus 0.03% ointment was applied to affected areas until clearance. In cases of exacerbation or clinical worsening, patients restarted treatment.

Results  Mean ± SD Eczema Area and Severity Index (EASI) score improved, from 11.2 ± 10.5 baseline to 2.6 ± 4.1 at endpoint (24 months); mean affected body surface area decreased from 25.2 ± 21.1% to 5.1 ± 9.0%, with improvement on all items of the Physicians’ Assessment of Individual Signs. The Physicians’ Global Evaluation of Clinical Response showed a result of “cleared”/“excellent” for 63.3% of patients; 85.7% of parents/guardians assessed symptoms as “much better.” Treatment was well tolerated, with common, nonserious respiratory infections and gastroenteritis the most frequently reported adverse events. The most common application‐site events were infections and pruritus. Over 98% of blood samples showed tacrolimus concentrations <1.0 ng/ml; >40% showed concentrations below the lower limit of quantification (0.0250 ng/ml).

Conclusions  Over a period of two years, tacrolimus 0.03% ointment was associated with substantial clinical improvement of AD in infants aged <2 years. Treatment tolerability was similar to that seen in older children.