AB0992 UTILITY OF SKIN BIOPSY IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS
Authors: C. G. Hobayan, A. Korman, J. Lin
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> The histological findings of systemic lupus erythematosus (SLE) include perivascular lymphocytic infiltration, epidermal atrophy, and hydropic degeneration of the basal layer, also known as interface dermatitis.<sup>[1]</sup> These findings are nonspecific, thus requiring clinicopathologic correlation. This may prove challenging in cases of clinically ambiguous skin rash presentations. <h3>Objectives:</h3> The objective of this study was to determine the utility of skin biopsy in patients presenting with a rash concerning for SLE to see if biopsy results are different from clinical diagnoses made by rheumatologists or dermatologists and changed management. The results of this study would help determine whether skin biopsy should be integrated into the workflow of patients undergoing workup for new presentation of SLE or in cases with known SLE but unclear if the rash is related. <h3>Methods:</h3> Patients with connective tissue diseases seen by rheumatology and dermatology who had a skin biopsy for a rash between 2015-2022 at a single institution were identified. Of these, 48 patients were assigned a clinical diagnosis of SLE and therefore selected for retrospective chart review. Collected data include skin biopsy results and changes in medical treatments. <h3>Results:</h3> In 27.1% of all cases in this study, biopsy results were discordant from clinical diagnosis; out of these cases, 69.7% of patients' medication regimens were changed following receipt of skin biopsy results (Table 1). For instance, biopsy results showing psoriasiform findings led to addition of methotrexate or apremilast. Biopsy results were concordant with clinical diagnosis in 72.9% of all cases in this study; out of these cases, only 34.3% of patients' medication regimens were changed following skin biopsy (Table 1). These changes involved increasing the number or dosage of immunosuppressive medications such as hydroxychloroquine and dapsone. <h3>Conclusion:</h3> Most patients presenting with a rash concerning for SLE are diagnosed clinically, and data on skin biopsy is limited. Of patients who underwent skin biopsy, biopsy results often supported the clinical diagnosis, but a different diagnosis was suggested histopathologically in 27% of cases, thus impacting management. Skin biopsy should be integrated in cases of clinical ambiguity. <h3>REFERENCES:</h3> [1] Teh YC, et al. Clinicohistological and immunopathological features of patients with cutaneous lupus erythematosus at tertiary dermatology centre in Malaysia. Clin Exp Dermatol 2022;47(8):1490-1501. <h3>Acknowledgements:</h3> This study was approved by the Institutional Review Board of the Ohio State University (#2023E0927) and supported by Award #UL1TR002733 from the National Center for Advancing Translational Sciences (NCATS). The content is solely the responsibility of the authors and does not necessarily represent the official views of NCATS or the National Institutes of Health. <h3>Disclosure of Interests:</h3> <b>None declared.</b>