Clinical Question: Is tacrolimus (Protopic) an effective treatment for Pityriasis alba?

Setting: Outpatient (specialty)

Study Design: Randomized controlled trial (single-blinded)

Allocation: Unconcealed

Synopsis: P. alba is characterized by hypopigmented macules and is associated with atopic dermatitis. Because tacrolimus is an effective treatment for the latter condition, these researchers thought it also might be helpful for P. alba. In this study, 60 children and young adults (age range = six to 21 years) with phototypes III or IV were randomly assigned to tacrolimus 0.1% ointment twice daily plus moisturizers with sunscreen or moisturizers with sunscreen alone. No placebo cream was used, so patients and the researcher doing the randomization knew the group assignment. However, the authors state that outcomes were evaluated by an investigator blinded to group assignment.

The groups were balanced at the beginning of the study; four patients dropped out of the tacrolimus group and six dropped out of the control group. Analysis was limited to those who completed the study. The primary outcomes were 3-point scores (0 = none, 3 = severe) for hypopigmentation, pruritus, and scaling. The greatest benefit of tacrolimus occurred for hypopigmentation, less benefit was seen for pruritus, and no benefit was seen for scaling. A transient burning sensation was reported by three patients in the tacrolimus group.

Bottom Line: Tacrolimus is an option for the treatment of P. alba. Note that this drug has not been approved for use in children younger than two years, and in all patients should be used for as short a time as possible because long-term use has been associated with an increased risk of lymphoma and skin cancer. Because P. alba is a self-limiting condition, with patients in the control group improving throughout the study, this expensive and potentially harmful agent should only be used after a careful discussion of the risks and benefits with patients and their parents. Moisturizers, sun block, and low-dose corticosteroids are first-line treatments. (Level of evidence: 1b)