Adult-Onset Henoch–Schönlein Purpura Triggered by Isotretinoin with Persistent Polyarthritis and Isolated Cutaneous-Gastrointestinal Involvement: A Case Report

Hussam Aldeen Mansour,1 Abdullah Alfandi,2 Aiman Abo Al Shamat,3 Abdalrhman Alras,4 Mohamad Nour Qanbar,5 Sameer Eshrifeh,5 Reham Almukbel,2 Hosin Alhaj Omar Khalil,2 Ali Jumaa,1 Mohammad Adi,1 Ahmad Anwar Alkheder11Faculty of Medicine, Damascus University, Damascus, Syria; 2Faculty of Medicine, Al-Sham Private University, Damascus, Syria; 3Faculty of Medicine, Al Andalus University for Medical Sciences, Tartus, Syria; 4Faculty of Medicine, Hama University, Hama, Syria; 5Faculty of Medicine, Syrian Private University, Damascus, SyriaCorrespondence: Abdalrhman Alras, Email [email protected]: IgA vasculitis (Henoch–Schönlein purpura, HSP) is a small-vessel vasculitis predominantly affecting children, while adult-onset disease is less common and often more severe, particularly with renal involvement. Drug-induced cases are rare, with only isolated reports linking isotretinoin to IgAV.Case Presentation: A 30-year-old woman developed palpable purpura, abdominal pain, and symmetric polyarthritis three weeks after starting isotretinoin. Laboratory evaluation showed mild inflammation with negative autoimmune workup and normal renal function; repeated urinalysis remained normal. Isotretinoin was discontinued, and corticosteroid therapy led to resolution of cutaneous and gastrointestinal symptoms. However, persistent inflammatory polyarthritis beyond six weeks required initiation of methotrexate, with subsequent improvement. No renal involvement developed during follow-up.Conclusion: This case highlights isotretinoin as a rare trigger of adult-onset IgAV and expands its clinical spectrum to include persistent, treatment-resistant arthritis without renal disease. Early recognition, drug withdrawal, and appropriate immunosuppression are key, with close renal monitoring recommended.Keywords: IgA vasculitis, henoch–schönlein purpura, isotretinoin, drug-induced vasculitis, polyarthritis