mrcp part 1 MCQ (SBA): Dermatitis Herpetiformis

A 24-year-old woman presents with a intensely itchy rash consisting of small vesicles and papules predominantly on her elbows, knees, buttocks, and scalp. She also mentions experiencing intermittent diarrhoea and bloating for several years. A skin biopsy shows subepidermal blistering with neutrophilic infiltrate in the dermal papillae and granular IgA deposition on immunofluorescence. What is the most likely underlying diagnosis?