S2k guideline for the treatment of hidradenitis suppurativa/acne inversa (ICD-10 code L73.2)

The aim of the S2k guideline on the therapy of hidradenitis suppurativa/acne inversa (HS/AI) is to provide an accepted decision-making aid for the selection and implementation of a suitable/sufficient therapy for patients with HS/AI. HS/AI is a chronic, relapsing, inflammatory, potentially mutilating skin disease of the terminal pilosebaceous glands that manifests with painful, inflammatory lesions in the apocrine glandular regions of the body, particularly the axillary, inguinal, and anogenital regions. Intensive clinical and experimental research and the review of new therapeutic approaches have almost completely renewed knowledge in the field of HS/AI since the publication of the old guideline in 2012. In Germany, a point prevalence of active disease of 0.3 % was observed, rising to 3.0 % when also taking into account patients with only scars typical of HS/AI. Pillars of HS/AI pathogenesis are abnormal differentiation of the keratinocytes of the pilosebaceous gland and massive accompanying inflammation. The primary lesions of HS/AI are inflammatory nodules, abscesses, and draining tunnels predominantly at predilection sites (axillary, submammary, inguinal, genital, and perineal). Recurrences in the last 6 months with at least 2 lesions at the sites of predilection indicate HS/AI. Although these criteria can be used to make a clinical diagnosis with a high accuracy of 97 %, the disease is still little known, as the delay in diagnosis in Germany of 10.0 +/- 9.6 years proves. Patients with HS/AI suffer from a significant reduction in quality of life, especially when there is a high degree of morbidity. In daily practice, HS/AI should be classified and its activity assessed using a validated instrument, primarily using the International Hidradenitis Suppurativa Severity Scoring System (IHS4), in order to be able to make correct treatment decisions. HS/AI is divided into two forms related to the severity of the always detectable inflammation, namely the active, inflammatory and the inactive, predominantly non-inflammatory forms. While the intensity of the inflammatory form is divided into mild, moderate and severe HS/AI using the IHS4 classification and treated accordingly with medications, the predominantly non-inflammatory form is treated surgically according to the Hurley grade of the affected location, namely Hurley-Grade I, II and III. Oral tetracyclines or 5-day intravenous clindamycin therapy are equivalent to the effectiveness of the oral systemic combination of clindamycin and rifampicin. The subcutaneously administered monoclonal antibodies adalimumab and secukinumab are approved for the treatment of HS/AI. Various surgical procedures are available for the predominantly non-inflammatory form of the disease. The combination of drug therapy to reduce inflammation with a surgical procedure to eliminate irreversible tissue damage is currently considered a holistic therapy procedure for HS/AI. Regular monitoring and, if necessary, adjustment of the therapy with regard to a changing degree of disease severity is recommended.