Clinical application of CLSM, dermoscope and Wood’s lamp in diagnosis and differential diagnosis of five hypopigmentation disorders

Objective: Noninvasive instruments including confocal laser scanning microscope (CLSM), dermoscope, and Wood’s lamp afford the advantage of obtaining skin microanatomical images quickly, in real-time, and dynamically. However, further understanding is needed regarding the differences between various techniques for diagnosis on hypopigmentation diseases. This study was aimed to observe the characteristics of hypopigmentation diseases by using CLSM, dermoscope, and Wood’s lamp, in order to provide evidence for clinician to choose appropriate instruments for assistant diagnosis. Methods: In total, data from 397 patients with vitiligo, nevus anemicus, achromic nevus, pityriasis alba, and senile leukoderma were collected from January 2019 to January 2021 in affiliated hospital of Xuzhou Medical University. CLSM, dermoscope, and Wood’s lamp were used to analyze the characteristics of lesions and the differences between the diseases. Enumeration data were presented as frequencies and percentages. Results: CLSM showed that the pigment ring of vitiligo was absent (126/126, 100.0%), senile leukoderma had hypopigmentation, skin atrophy and thinning, and flat epidermis mutation (79/79, 100.0%). In dermoscope, vitiligo showed a milky white hypopigmented area (113/126, 89.8%), nevus anemicus showed a clear but irregular (38/45, 84.4%) white hypopigmentation area (41/45, 91.1%), pityriasis alba showed a clear and light white hypopigmented area, with a grayish-white chaff-like scaly appearance (98/107, 91.6%), senile leukoderma showed a white radially hypopigmentation area with a small amount of pigmentation (79/79, 100.0%). Under Wood’s lamp, bright blue-white patches with clear boundaries can be observed in vitiligo, nevus anemicus, pityriasis alba (93/107, 86.9%) and senile leukoderma appeared clear bluish-white patches, achromic nevus appeared unclear bluish-white patches, respectively. Conclusion: Vitiligo, nevus anemicus, achromic nevus, pityriasis alba, and senile leukoderma all belong to hypopigmentation diseases, however, they have own imaging characteristics under CLSM, dermoscope, and Woods lamp techniques, which may be used to help the diagnosis and differential diagnosis of these diseases.