Vascularization and fibrosis are important ultrasonographic tools for assessing response to adalimumab in hidradenitis suppurativa: Prospective study of 32 patients

Hidradenitis suppurativa (HS) is a debilitating skin disease presenting with nodules, abscesses, and fistulae preferentially in the main folds. Adalimumab is the only licensed biologic for moderate-to-severe HS. Ultrasound demonstrated good sensitivity to provide anatomic and functional information in HS; in particular assessing vascularization, related to inflammation, and fibrosis in HS lesions before and after adalimumab treatment with ultrasound and Color Doppler may integrate clinical evaluation with imaging. Patients with moderate-to-severe HS were enrolled in this observational prospective study. Clinical evaluation (according to Hurley classification and International Hidradenitis Suppurativa Severity Score System score) and ultrasound (according to US HS-PGA)/Color Doppler were performed at baseline and after 12 weeks of adalimumab. Ultrasound was used for assessing fibrosis and Color Doppler for vascularization. For each patient, the three most severe lesions among abscesses and fistulae were chosen for total 96 lesions. Thirty-two patients were included, 18 men (56%) and 14 women (44%) with mean age 41.2. Mean IHS4 was 22.4 at baseline and dropped to 14.7 at week 12. Based on US HS-PGA, 14 out of 32 patients fell down by one or more classes of severity. Interestingly, adalimumab led to overall decrease in vascularization, particularly in lesions with intense vascular flow, which were 78 (81.3%) at baseline and became only 25 (26.04%). Finally, marked increase in fibrosis was seen after adalimumab, notably in lesions without fibrosis, which were 81 (84.4%) at baseline and became 15 (15.6%). This study confirms the efficacy of adalimumab in HS and provides value for vascularization and fibrosis as important ultrasonographic tools integrating clinical scores.