Classification of melasma by UV Light dermoscopy (Peak at 400nm) : a comparative study with dermoscopy and Wood's Lamp = Classification of melasma by UV Light dermoscopy (Peak at 400nm) : a comparative study with dermoscopy and Wood's Lamp

다국어 초록 (Multilingual Abstract)

Background: UV light can be used to measure the margin and depth of pigmented lesions. But, there have been no studies to classify the histologic type of melasma using UV light dermoscopy which has both features of dermoscopy and Wood's lamp. Objectives: The goal of this study is to compare the diagnostic accuracy of UV light dermoscopy with that of dermoscopy and Wood's lamp in determining the histologic type of melasma. Methods: Thirty patients with melasma on the face were evaluated by two expert examiners independently, using dermoscopy (IDS-1100ILLUCO^(R) 10x), Wood's light(Dermavision^(R) UVA 360nm) and UV light dermoscopy(IDS-2100 ILLUCO^(R) 10x). Later, the observed findings were compared with the histologic findings. Results: Compared with biopsy specimen, the diagnostic accuracy via Wood's light, dermoscopy and UV light dermoscopy in distinguishing histologic type of melasma were 23.3%, 40% and 80%, respectively. The increase in contrast at the 400nm region was interrelated with an increased amount of melanin in the basal layer(P=0.013). The increased contrast variation on UV light dermoscopy was correlated with increased dermal free melanin(P=0.001) and melanophage(P=0.004). In addition, globular pattern observed on UV light dermoscopy indicated the increased melanin pigment of stratum basalis(P=0.014). Conclusion: UV light dermoscopy can be considered an accurate diagnostic equipment in the estimating the depth and border of melasma.