Dermatology: Practical and Conceptual Image Letter | Dermatol Pract Concept. 2025;15(1):4975 1 PASS Syndrome: Clinical Observation Olga Valentinovna Grabovskaya1, Natalia Pavlovna Teplyuk1, Anna Evgenievna Bobkova1, Vera Nikolaevna Busol1 1 The N.V. Sklifosovsky Institute of Clinical Medicine of the Federal State Autonomous, Educational Institution of Higher Education I.M. Sechenov First Moscow State Medical University of the Ministry of Health of Russia, Sechenov University Citation: Grabovskaya OV, Teplyuk NP, Bobkova AE, Busol VN. PASS syndrome: clinical observation. Dermatol Pract Concept. 2025;15(1):4975. DOI: https://doi.org/10.5826/dpc.1501a4975 Accepted: October 18, 2024; Published: January 2025 Copyright: © Grabovskaya 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. Ethics Statement: This study was conducted in accordance with the Declaration of Helsinki (approval number: 201710826). The collection and evaluation of all protected patient health information was performed in a Health Insurance Portability and Accountability Act (HIPAA)-compliant manner. Corresponding Author: Anna E. Bobkova, The N.V. Sklifosovsky Institute of Clinical Medicine of the Federal State Autonomous, Educational Institution of Higher Education I.M. Sechenov First Moscow State Medical University of the Ministry of Health of Russia, Sechenov University. E-mail: anya_bobkova98@mail.ru Case Presentation A 37-year-old man presented with long-term non-healing cu- taneous ulcerations. According to medical records, in 2014 he was treated with systemic retinoids due to acne vulgaris and Hoffmann undermining folliculitis. In 2020 he noted pain in large joints and rash in the axillary, abdomen, and groin regions and shins. He was diagnosed with Crohn disease and axial spondyloarthritis (sacroileitis) and started infliximab; however, the prescription was canceled because of the dete- riorating cutaneous process. He received 3 netakimab injec- tions with no positive dynamics. In 2023 he was diagnosed with seronegative rheumatoid arthritis and started anakinra. In 2024 cutaneous ulcerations resistant to topical treatment appeared on the right shin and lower abdomen. Physical examination revealed cutaneous ulcerations located on the right shin (Figure 1A) and lower abdomen (Figure 1B), with undermined, reddish-violet edges, intensively painful, sur- rounded by erythema, and partially covered with necrotic debris. Pinkish nodules were noted on the scalp, back, and gluteal regions (Figure 1C). Cribriform scars were seen on the left arm and shin. In the axillary regions fistulas and cord- like scars were observed (Figure 1D); cord-like scars were also seen in the right ear area. Prednisolone (30 mg/day), doxycycline (200 mg/day) and corrective therapy in combi- nation with local treatment were prescribed, and the regres- sion of the cutaneous process was observed. Teaching Point PASS syndrome (pyoderma gangrenosum, acne vulgaris [A], hidradenitis suppurativa [SH/S], and axial spondyloarthritis [AS/S]) is a rare auto-inflammatory condition characterized by a chronic relapsing course [1,2]. Owing to the rarity of the con- dition, there are no treatment guidelines for PASS-syndrome, but immunosuppressive agents (in particular systemic cortico- steroids) are successfully used, providing a positive response and eventual healing of cutaneous defects [1]. 2 Image Letter | Dermatol Pract Concept. 2025;15(1):4975 References 1. Saternus R, Schwingel J, Müller CSL, Vogt T, Reichrath J. Ancient friends, revisited: Systematic review and case report of pyo- derma gangrenosum-associated autoinflammatory syndromes. J Transl Autoimmun. 2020 Nov 20;3:100071. DOI: 10.1016/j. jtauto.2020.100071. PMID: 33305249. PMCID: PMC7718158. 2. Olisova OY, Teplyuk NP. Illustrated guide to dermatology. Moscow: GEOTAR-Media; 2022: 254-257 (Russian). Figure 1. PASS syndrome in a 37-year-old man. (A) Typical of pyoderma gangrenosum cutaneous ulcerations with undermined, reddish-violet edges, intensively painful, surrounded by erythema, and partially covered with necrotic debris, located on the right shin. (B) Characteristic of pyoderma gangrenosum cutaneous ulcerations with undermined, reddish-violet edges, surrounded by pink erythema, located on the lower ab- domen. (C) Suggestive of acne multiple, pinkish nodules located on the skin of the back and gluteal region. (D) Typical of hidradenitis suppurativa fistulas and cord-like scars located in the right axillary region.