Hidradenitis suppurativa (HS) is a common inflammatory skin disease. Medical 
treatment is often disappointing and in severe disease surgery remains the 
therapy of choice. Extensive surgery may be effective but also mutilating. 
Patients experience a significant reduction in quality of life and the need for 
new treatment modalities are urgent. In recent years patients with HS have been 
treated off-label with tumour necrosis factor-alpha (TNF-alpha) inhibitors with 
a varying degrees of effect. We performed a systematic review of papers 
retrieved from two databases (PubMed and Web of Science) using the follow-ing 
keywords: hidradenitis suppurativa, acne inversa, infliximab, etanercept, and 
adalimumab. A total of 34 publications were retrieved, describing treatment of 
105 patients. Most cases report treatment with infliximab (52/105). A positive 
treatment outcome was reported in 90/105 cases, with only 7/105 non-responders 
and 8/105 patients experiencing side-effects. The side-effects were comparable 
to those seen in other TNF-alpha inhibitor studies. In the majority of cases the 
treatment was effective when given as a suppressive therapy, but 15/105 cases 
were described with long-term remission (>or= 3 months) after the end of 
therapy. In most publications follow-up was, however, insufficient to allow a 
systematic exploration of this. TNF-alpha inhibitors seem to be effective in the 
treatment of HS. However, several questions remain to be answered through 
specific studies. This review has also identified a need for more standardized 
reporting of the outcomes as well as randomized controlled trials in this 
disease.