Topical tacrolimus significantly promotes repigmentation in idiopathic guttate hypomelanosis: a double-blind, randomized, placebo-controlled study.

BACKGROUND: Idiopathic guttate hypomelanosis (IGH) is an idiopathic disorder affecting a large number of people. Effective treatments are not yet available. Objectives To investigate the efficacy of topical 0.1% tacrolimus ointment compared with placebo in the treatment of IGH. MATERIALS AND METHODS: Twenty-six patients were included in the study. Lesions on one side of the body were selected to have a treatment with 0.1% tacrolimus ointment, whereas those on the other side served as a control with placebo ointment that had the same physical appearance. Colorimeter was used to assess skin colour at baseline and at 1, 2, 3, 4 and 6 months of treatment. RESULTS: Mean luminosity scale after adjusted for baseline from the treated side gradually decreased and reached statistical significance compared with the control group after 6 months of treatment (P = 0.019). Physicians' improvement grading score showed that 11% of the patients demonstrated improvement of their skin lesions on the treated side after 6 months' treatment. CONCLUSION: Topical 0.1% tacrolimus ointment appeared to be an effective and safe treatment for IGH. The improvements were best observed by colorimetry, yet, they were not statistically significant upon clinical assessments.

Up-regulation of Id1 in peripheral blood of psoriatic patients.

Although the precise causes of psoriasis are unclear, it is widely accepted that psoriasis is a disorder in which factors in the immune system, enzymes, and other biochemical substances that regulate skin cell division are impaired, leading to rapid proliferation of keratinocytes and incomplete keratinization. Expression of the helix-loop-helix transcription factor Id1 (inhibitor of differentiation/DNA binding), functioning as an inhibitor of differentiation, is known to increase in psoriatic skin. However, the molecular involvement of this particular biomarker in the psoriatic immune system remains to be elucidated. We measured Id1 mRNA expression in peripheral blood mononuclear cells (PBMCs) of psoriatic patients and healthy controls using semi-quantitative reverse transcriptase-PCR. The normalized level of Id1 transcripts in psoriatic patients was about 2-fold higher than that in controls (P < 0.05). When we examined the proliferation rate of PBMCs, the stimulation index obtained from the phytohemagglutinin stimulation assay was not significantly different in psoriatic patients. In patients with psoriasis, there was no correlation between the stimulation index and the psoriasis area severity index. We suggest that Id1 has a role in causing psoriatic immune cell symptoms.