Romina Muguruza, Unidad Académica de Dermatología Médico-Quirúrgica, Hospital de Clínicas, Montevideo, Uruguay
Lucía Farías, Unidad Académica de Dermatología Médico-Quirúrgica, Hospital de Clínicas, Montevideo, Uruguay
Gabriela Otero, Unidad Académica de Dermatología Médico-Quirúrgica, Hospital de Clínicas, Montevideo, Uruguay
Background: Chronic lower-extremity ulcers are frequently associated with microbial colonization and infection, making diagnosis challenging. Wood’s lamp examination has been proposed as a non-invasive method for detecting microorganisms through fluorescence patterns. Objective: To evaluate the diagnostic performance Wood’s lamp and their correlation with microbiological findings. Material and methods: A prospective observational analytical diagnostic-accuracy study was conducted at a chronic wound clinic in 2022. Patients with chronic lower-extremity ulcers, with or without clinical signs suggestive of infection according to EWMA criteria, were included. Ulcers were examined using a Wood’s lamp under standardized conditions, followed by exudate sampling using the Levine technique for microbiological analysis. Associations between variables were assessed using Fisher’s exact test. Results: Forty ulcers from 20 patients were analyzed (70% male, mean age 69 ± 7.6 years). Bacterial growth was detected in 75% of ulcers, predominantly as polymicrobial flora (57.5%). The most frequently isolated microorganisms were Staphylococcus aureus and Pseudomonas aeruginosa. Fluorescence patterns were mainly associated with tissue components, including fibrin, granulation/hypergranulation tissue, and keratin. Only one ulcer showed red fluorescence associated with S. aureus isolation. No yellow-green fluorescence was observed in ulcers yielding P. aeruginosa. No significant association was found between clinical signs suggestive of infection and microbiological growth (p = 0.16). Conclusions: Wood’s lamp examination showed poor correlation with microbiological findings and was not useful for identifying microorganisms or guiding microbiological sampling in chronic lower-extremity ulcers. Its findings should be interpreted in conjunction with clinical and microbiological assessment.
Keywords: ulcer. Wound infection. Microbiology. Exudates. Diagnostic techniques.