Subjective versus objective recognition of facial vitiligo lesions: detection of subclinical lesions by Wood’s light

Background Visual recognition of alteration in the skin color depends upon the contrast between altered areas and their surrounding background color. The maximum contrast in vitiligo exists in dark-complexioned patients between depigmented white patches and unaffected background dark skin. On the other hand, hypopigmented and even depigmented lesions may not be easily recognizable in fair skin due to less contrast. Wood’s light examination becomes essential in such cases for better recognition and definition of the lesions. Despite its established role, the exact added value of using Wood’s light in recognition of vitiligo lesions has not been previously studied. Objective To verify the differential perception of vitiligo lesions between the patient and the dermatologist compared with the gold-standard detection by Wood’s lamp. Patients and methods This multicenter cross-sectional study included 200 vitiligo patients. The distribution and surface area of their facial lesions were delineated and measured as perceived by the patient, and by the dermatologist in standardized regular light and using Wood’s lamp. Results Lesional surface area as perceived by the patient and the dermatologist in regular light did not differ significantly (P=0.137), while lesions delineated under Wood’s lamp were significantly larger than both (P<0.001 in both instances), due to the detection of new clinically invisible lesions and/or invisible extensions to clinically visible lesions. The presence of these subclinical lesions was not related to Fitzpatrick’s skin phototype, vitiligo clinical type, duration, or activity score. Conclusion Subclinical lesions represent a new addition to the current spectrum of vitiligo presentations. Their detection in the current study depended solely on Wood’s light examination; hence, its use should be integral to vitiligo patient assessment. Pointing out these lesions to the patient is essential for proper application of local medications.