Atopic labial pigmentation: a new diagnostic feature in Asian patients with atopic dermatitis.

BACKGROUND: Pigmented lesions on the lips can be caused by physiological or pathological factors, along with exogenous or endogenous factors. Many patients with atopic dermatitis (AD) and labial pigmentation are seen in clinical practice. The aim of our study was to further explore the association of labial pigmentation and AD.

METHODS: We performed a retrospective chart review of patients who visited the Department of Dermatology at Kyung Hee Medical Center, Seoul, Korea, from January 1 to December 31, 2016. The study consisted of 178 patients with AD and a control group of 178 age- and sex-matched patients without AD.

RESULTS: The patients with AD had both a significantly higher prevalence of labial pigmented lesions and a significantly higher number of labial pigmented lesions than was observed in the control group. Moreover, the pigmented lesions were found mainly in the middle section of the upper lip and showed multifocal distribution. The patients with AD and labial pigmentation were significantly younger at the onset of AD, showed a greater association with allergic disorder, and had a higher immunoglobulin E (IgE) level than patients without labial pigmentation.

CONCLUSION: Our findings strongly suggest that labial pigmentation occurs in patients with AD. Although labial pigmentation was not present in all patients with AD, this might be a particularly helpful diagnostic feature of AD in Asian patients.