Bacterial infection plays an important role in hidradenitis suppurativa (HS). This infection has a number of unique features: chronicity, absence of lymph node involvement, and absence in most cases of acute super-infection by Staphylococcus aureus and/or streptococci. Treatment is based mainly on antibiotics. Various bacteria are involved; they are often part of the resident flora and may combine in polymicrobial infections, and they consist mainly of two families: coagulase-negative staphylococci (CNS) and anaerobes. Numerous antibiotics are active against CNS: betalactamins, lincosamides, macrolides, rifampicin, tetracyclines and fluoroquinolones. Antibiotics active against anaerobes include metronidazole, betalactamins, lincosamides and one fluoroquinolone (moxifloxacine). Antibiotics are given per os and in combination. Treatment is usually long-term, with a frequent need for maintenance therapy. It ha; to be tailored to various clinical situations: intermittent development, in which "abortive" emergency treatment is used; major or major continuous forms, where combined antibiotics are used, most frequently rifampicin and clindamycin. The global treatment strategy involves a surgical approach, which can be aided but not replaced by antibiotics. While the risks of long-term antibiotic use are reduced in this specific population of "healthy" young adults, they are not absent. (C) 2012 Elsevier Masson SAS. All rights reserved.