Delphi consensus: First-line use of biologics and small molecules in hidradenitis suppurativa.

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease associated with significant diagnostic delays and impact on quality of life. Current guidelines prioritize antibiotics as first-line therapy, but experts increasingly recognize the need for earlier targeted therapy intervention to prevent irreversible scarring and tunnel formation. To establish consensus on clinical scenarios during the 14th European Hidradenitis Suppurativa Foundation Conference in February 2025, 54 HS experts participated in a Delphi consensus, using a Likert scale (-5 to +5) to vote on 16 statements concerning first-line therapy criteria with biologics and/or small molecules for eligible patients. Seventy-eight HS experts were invited, and 54 participated via hybrid onsite and electronic voting. Experts rated 16 pre-defined statements regarding first-line use of biologics and/or small molecules for HS using a Likert scale (-5 to +5). Agreement metrics were stratified as majority agreement (≥70%, median 3.0-3.5), consensus (≥75%, median 3.5-4.5), and strong consensus (≥90%, median ≥4.5). Statements were subsequently ranked for clinical relevance. Strong consensus was reached for patients contraindicated for antibiotics, rapid disease progressors and those with severe disease. Consensus also supported upgrading patients with moderate disease (IHS4 ≥ 4), frequent flares (≥3 in 12 weeks), multiple affected areas and specific phenotypes including anogenital involvement. Strong consensus emerged for syndromic HS and for patients with inflammatory comorbidities such as inflammatory bowel disease and arthritis. Paediatric patients with a positive family history and moderate disease were also considered candidates for first-line biologics or small molecules. This consensus provides evidence-based criteria for upgrading HS patients to first-line biologic therapy, reflecting expert practices across Europe aimed at preventing irreversible disease progression. The results support a 'hit hard and early' approach to minimize scarring and tunnel formation, although prospective studies are still needed to validate these expert-driven recommendations.