Post-Stevens-Johnson Syndrome Bronchiolitis Obliterans: Report of a Complex Case and a Literature Review.

Bronchiolitis obliterans (BO) is a rare and severe respiratory complication of Stevens-Johnson syndrome (SJS), which primarily affects the small airways and causes progressive respiratory decline. We present the case of a young male with autism spectrum disorder who developed BO after an episode of SJS triggered by amoxicillin. Initially, the patient presented with an ulcerative rash and respiratory symptoms and received high-dose corticosteroids, leading to partial resolution of mucocutaneous lesions. However, his respiratory symptoms progressively worsened, and he was initially misdiagnosed with asthma, which delayed the appropriate treatment. Imaging and pulmonary function tests (PFTs) revealed findings consistent with BO, including mosaic attenuation, airway thickening, and severe obstruction without reversibility. After infectious and autoimmune causes were ruled out, management included high-dose corticosteroids and fluticasone, azithromycin, and montelukast (FAM) therapy, resulting in partial clinical improvement. Recognising the progressive nature of post-SJS BO, the patient was referred to a tertiary centre for lung transplantation. This case highlights the importance of early diagnosis and tailored management, including potential transplantation, in patients with severe post-SJS BO.