Supplementary Material for: An unusual case of fibromatous fibrosis in a young hidradenitis suppurativa patient

Hidradenitis suppurativa (HS) is a chronic inflammatory condition of the hair follicles in apocrine gland-rich areas, characterized by painful nodules, abscesses, sinus tracts, and fibrosis. Treatment aims to reduce inflammation, control symptoms, and prevent progression, with TNF-α inhibitors like adalimumab being effective for moderate-to-severe cases. This report presents a 26-year-old female with recurrent HS lesions in the intermammary fold, treated with adalimumab and intralesional corticosteroids for a keloid-like lesion. While systemic therapy improved inflammatory lesions, the keloid-like lesion progressed, prompting biopsy to exclude malignancy. Histopathology revealed benign fibromatous fibrosis, highlighting the diagnostic challenges of HS-associated lesions. This case underscores the efficacy of TNF-α inhibitors, the complexity of managing concomitant keloids, and the need for vigilant monitoring and histological evaluation to differentiate benign from malignant conditions. A multidisciplinary approach is essential for optimal HS management, particularly in patients with atypical or treatment-resistant lesions.