Dermatology: Practical and Conceptual Image Letter | Dermatol Pract Concept. 2024;14(4):e2024272 1 Eosinophilic Polymorphous Pruritic Eruption Associated With Radiotherapy: Clinical, Dermoscopic, and Histological Aspects Lorenzo D’Alì1, Laura Fagotto2, Giuseppe Stinco3, Alessandro Pileri4, Corrado Zengarini4, Alba Guglielmo2,4 1 Institute of Pathology, Academic Hospital of Udine, Department of Medicine, University of Udine, Udine, Italy 2 Institute of Dermatology, Azienda Sanitaria Universitaria Friuli Centrale (ASUFC), Udine, Italy 3 Department of Medicine (DAME), University of Udine, Udine, Italy 4 Dermatology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Policlinico S. Orsola-Malpighi, Bologna, Italy Citation: D’Alì L, Fagotto L, Stinco G, Pileri A, Zengarini C, Guglielmo A. Eosinophilic Polymorphous Pruritic Eruption Associated With Radiotherapy: Clinical, Dermoscopic, and Histological Aspects. Dermatol Pract Concept. 2024;14(4):e2024272. DOI: https:// doi.org/10.5826/dpc.1404a272 Accepted: July 2, 2024; Published: October 2024 Copyright: ©2024 D’Alì 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: All authors have contributed significantly to this publication. Corresponding Author: Alba Guglielmo, Institute of Dermatology, Azienda Sanitaria Universitaria Friuli Centrale (ASUFC), Udine, Italy. Telephone +39 0432559820 E-mail: albaguglielmo@gmail.com Case Presentation A 67-year-old woman with an HPV-positive squamous cell carcinoma of the uterine cervix received cisplatin as- sociated with radiotherapy (95 Gy). One week before the radiotherapy completion, she developed a diffuse polymor- phous pruritic rash characterized by erythematous crusted papules and rare vesicles, mainly affecting upper and lower limbs (Figure 1A). She denied insect bites or taking any new medications. Laboratory investigations, including anti-BP180/230 and anti-desmoglein 1/3 antibodies, were negative. Dermoscopy showed a pinkish papule with dilated polymorphic vessels surrounded by a whitish desquamative collarette (Figure 1B). A punch biopsy revealed a vesicular subepidermal bullous dermatosis associated with a superficial and deep infiltrate with perineural and perieccrine disposition (Figure 1C). The diagnosis of eosinophilic, polymorphous, pruritic eruption associated with radiotherapy (EPPER) was made [1-2]. Teaching Point Eosinophilic Polymorphous Pruritic Eruption Associated with Radiotherapy (EPPER) is characterized by a diffuse pruritic skin eruption and is generally observed in female cancer patients during radiotherapy or after its completion. The differential diagnosis with other dermatoses character- ized by eosinophils, including eczema, bullous pemphigoid, exaggerated insect bites-like reactions, or drug adverse reac- tion, might be difficult, and a careful evaluation of the clin- ical history, skin examination, and histology are mandatory for achieving the correct diagnosis. Dermatoscopic exam- ination of further cases could add new clues to guide the differential diagnosis. 2 Image Letter | Dermatol Pract Concept. 2024;14(4):e2024272 References 1. Rueda RA, Valencia IC, Covelli C, Escobar C, Alzate A, Saldarriaga B, et al. Eosinophilic, polymorphic, and pru- ritic eruption associated with radiotherapy. Arch Dermatol. 1999;135:804‐810. DOI:10.1001/archderm.135.7.804 2. Löbelenz L, Schliep S, Wörl P, Uslu U. Eosinophilic polymorphic and pruritic eruption associated with radiotherapy: case report and overview of disease characteristics. Clin Exp Dermatol. 2019;44:567-569. DOI:10.1111/ced.13821 Figure 1. (A) Diffuse polymorphous pruritic rash characterized by erythematous crusted papules and rare vesicles. (B) Dermoscopy showed a pinkish papule with dilated polymorphic vessels surrounded by a whitish desquamative collarette. (C) Vesicular subepidermal bullous der- matosis associated with a superficial and deep infiltrate, perineural and perieccrine disposition.