Through the Lens: A Comparative Analysis of In Vivo Reflectance Confocal Microscopy and Dermoscopy in Diagnosing Fusarium and Trichophyton rubrum-Induced Onychomycosis
Bildiriler > Tam Metin Bildiri · 2023
Yazarlar: Ayris ÖZTÜRK, Nilay DUMAN, Banu YAMAN, Işıl TUNA
32nd Congress of the European Academy of Dermatology and Venereology, Almanya, Berlin, Uluslararası, Poster, Tam Metin Bildiri, 2023-2023, cilt -, ss ---
Özet
<p><strong>Introduction & Objectives:</strong></p><p>Onychomycosis (OM), a common fungal infection, poses diagnostic challenges due to the limitations of conventional methods. Early identification of the causative fungi is crucial to prevent nail dystrophy and loss. Dermoscopy and in vivo reflectance confocal microscopy (RCM) offer promising diagnostic tools to enhance mycological detection. This case series presents successful diagnoses of OM using RCM and discusses the distinctive features of Fusarium and Trichophyton rubrum, which were confirmed through potassium hydroxide (KOH) examination and fungal culture, while comparing the findings with literature.</p><p><strong>Materials & Methods:</strong></p><p>A 66-year-old woman presented with yellow-white discoloration and leukonychia in the proximal 4th finger of the left hand, while a 45-year-old male patient exhibited black, brown, and yellow discoloration, and subungual hyperkeratosis of both great toenails. Dermoscopy, RCM, direct microscopic examination with KOH culture, and histopathological evaluation (HP) of full-thickness nail clippings using Periodic Acid-Schiff and Grocott’s Methenamine Silver stains were performed.</p><p><strong>Results:</strong></p><p>KOH examination revealed fungal elements consisting of spores and mycelium, as well as only spores, respectively. HP confirmed OM in both cases, with the presence of mycotic hyphae and spores. Fusarium proliferatum and Trichophyton rubrum were identified as the fungal growth on culture, respectively.</p><p>In the first case, dermoscopy revealed characteristic features of proximal white subungual OM, including a white- yellow structureless opacity including the lunula, white transverse striate pattern, superficial white opaque clods, and yellow-brown discoloration. Second case exhibited fungal melanonychia with black-brown longitudinal bands, yellow-white longitudinal striae, an aurora borealis pattern, subungual hyperkeratosis with a ruins aspect, and a distal irregular termination, indicative of total dystrophic OM. RCM revealed bright hyper-reflective roundish structures in both cases, as well as aggregates of bright, refractile, linear branching filamentous structures in the second case. These findings were consistent with the culture results, indicating correlation between RCM and culture findings.</p><p><strong>Conclusion:</strong></p><p>Dermoscopy offers a cost-effective approach to identify microscopic features, while RCM provides high-resolution imaging for real-time evaluation, by penetrating nails at depths of 400–500 μm, allowing the identification of fungal colonies. Dermoscopy reveals yellow-white streaks corresponding to fungal colonies extending proximally, while the presence of multicolored streaks creates an aurora borealis pattern. In RCM, hyphae appear as bright, linear, prolonged, thready-like, branching, and filamentous structures, while spores exhibit a bright, roundish appearance with high reflection.</p><p>Further studies are needed to explore the diagnostic utility of RCM in larger patient populations. RCM offers a fast, non-invasive, and convenient approach to diagnosing onychomycosis, providing in vivo insights for treatment planning and valuable information about the specific fungal infection type.</p>