Dermatology: Practical and Conceptual Research Letter | Dermatol Pract Concept. 2025;15(2):5231 1 Ultraviolet Enhanced Trichoscopy – a New Tool to Assess Pili Annulati Katarzyna Korecka1, Anna Słomiak – Wąsik2, Magdalena Jałowska2, Honorata Kubisiak-Rzepczyk1, Adriana Polańska1, Aleksandra Dańczak-Pazdrowska2 1 Department of Dermatology and Venereology, Poznań University of Medical Sciences, Poznań, Poland 2 Department of Dermatology, Poznań University of Medical Sciences, Poznań, Poland Key words: pili annulati, trichoscopy, ultraviolet enhanced trichoscopy, hair shaft disorders Citation: Korecka K, Słomiak – Wąsik A, Jałowska M, Kubisiak-Rzepczyk H, Polańska A, Dańczak-Pazdrowska A. Ultraviolet Enhanced Trichoscopy – a New Tool to Assess Pili Annulati. Dermatol Pract Concept. 2025;15(2):5231. DOI: https://doi.org/10.5826/dpc.1502a5231 Accepted: February 5, 2025; Published: April 2025 Copyright: ©2025 Korecka et al. This is an open-access article distributed under the terms of the Creative Commons Attribution- NonCommercial License (BY-NC-4.0), https://creativecommons.org/licenses/by-nc/4.0/, which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original authors and source are credited. Funding: None. Competing Interests: None. Authorship: KK – conceptualization, visualization, data collection, data analysis, writing – original draft, ASW – visualization, data collection, writing- original draft, MJ- supervision, conceptualization, data analysis, writing- original draft, HKR- visualization, writing- original draft, AP - writing- original draft, supervision, ADP- supervision, conceptualization, writing-original draft. Corresponding Author: Katarzyna Korecka. Department of Dermatology and Venereology, Poznań University of Medical Sciences, Przybyszewskiego 49, 60-356 Poznan, Poland. ORCID ID: 0000-0002-9473-1239. E-mail: kasia.korecka@gmail.com Introduction Pili annulati is a hair shaft disorder which is frequently un- derdiagnosed. Its typical features consist of air-filled cavities located within the hair cortex that create the so-called “band- ing pattern.” [1]. They reflect the light and therefore can be seen as a dark band in transmitted light microscopy [2]. Pili annulati is considered an autosomal dominant disease; how- ever, there have been reports of its appearance along other conditions such as alopecia areata or trichorrhexis nodosa [1, 2]. Clinically, the hair shafts are usually shiny and bright. On trichoscopy, hair shafts reveal white and dark bands in both dark and blonde hair, and 20%-80% of hair are usually affected [3]. This condition rarely causes any complications; nevertheless, hair fragility and brittleness have been reported [1]. Most patients have no concomitant abnormalities, and they are often unaware of the condition [4]. UV-enhanced dermatoscopy has been explored as a novel technique with many different, new indications for its use in general der- matology, trichoscopy, onychoscopy, and dermato-oncology [5]. Herein, we present a case of a 22-year-old patient with pili annulati diagnosed with handheld trichoscopy and the application of UV-enhanced trichoscopy. Case Presentation A 22-year-old female patient presented to a dermatology out- patient clinic asking for a hair examination. She complained of a partial hair loss two months prior to her visit. She re- ported no concomitant disease. According to the patient, she had developed several hairless patches; however, they had regrown. Trichoscopy was performed with a handheld der- moscope (DermLite DL5 device), which allows performing dermoscopy with polarized and 365nm UV light. On regular trichoscopy (×10 magnification), dark and light bands were seen. UV-enhanced trichoscopy revealed blue bands, possibly 2 Research Letter | Dermatol Pract Concept. 2025;15(2):5231 Conclusion Although 20x magnification trichoscopy may be considered a standard device for hair shaft abnormality assessment, applying a handheld device with a UV-enhanced trichos- copy mode may help facilitate the correct diagnosis in case of videodermatoscope unavailability. The air-filled cavities that were at first not clearly visible in polarized light were enhanced by UV-enhanced trichoscopy, which, in our opin- ion, may be a valuable additional tool to make the correct diagnosis in a clinical setting. We assume that the patient experienced an episode of alopecia areata, whereas the con- currence of these two entities remains unclear since only a few cases have been reported in the literature [6]. Pili an- nulati is usually a benign, isolated condition which is often underdiagnosed due to its rarity. The treatment is usually not indicated, as in most hair shaft abnormalities. We believe that UV-enhanced trichoscopy to be a new, easily available, additional tool to establish the correct diagnoses in clinically difficult cases. References 1. Gonzalez AM, Borda LJ, Tosti A. Pili Annulati with Severe Trichorrhexis Nodosa: A Case Report and Review of the Litera- ture. Skin Appendage Disord. 2019;5(2):114-116. DOI:10.1159 /000491910 2. Castelli E, Fiorella S, Caputo V. Pili Annulati Coincident with Alopecia Areata, Autoimmune Thyroid Disease, and Primary IgA Deficiency: Case Report and Considerations on the Liter- ature. Case Rep Dermatol. 2012;4(3):250-255. DOI:10.1159 /000345469 3. Rudnicka L, Olszewska M, Waśkiel A, Rakowska A. Trichoscopy in Hair Shaft Disorders. Dermatol Clin. 2018;36(4):421-430. DOI:10.1016/j.det.2018.05.009 4. Giehl KA, Rogers MA, Radivojkov M, et al. Pili annulati: refine- ment of the locus on chromosome 12q24.33 to a 2.9-Mb inter- val and candidate gene analysis. British Journal of Dermatology. 2009;160(3):527-533. DOI:10.1111/j.1365-2133.2008.08948.x 5. Rudnicka L, Olszewska M, Rakowska A, Slowinska M. Trichos- copy update 2011. J Dermatol Case Rep. 2011;5(4). DOI:10.3315 /jdcr.2011.1083 6. Giehl K, Schmuth M, Tosti A, et al. Concomitant Manifestation of Pili Annulati and Alopecia Areata: Coincidental Rather than True Association. Acta DermatoVenereologica. 2011;91(4): 459-462. DOI:10.2340/00015555-1088 Figure 1. (A) Clinical presentation of the hairs. (B) Light microscopy reveals a hair shaft with dark bands within the hair cortex. Dimethyl sulfoxide (DMSO) medium artifacts are visible around the hair shaft (×40). (C, E) Pili annulati in trichoscopy and (D, F) UV-enhanced trichoscopy (DermLite DL5, ×10 magnification): dark and light bands within the hair shafts. UV-enhanced trichoscopy revealed blue bands, possibly due to the UV light penetrating through the air-filled cavities. due to the UV light penetrating through the air-filled cavi- ties (Figure 1). The bands were more visible in UV-enhanced trichoscopy than in the regular polarized mode. On light mi- croscopy (×40), a hair shaft with dark bands was detected. A diagnosis of pili annulati was established.