title: Paradoxical responses after start of antimicrobial treatment in Mycobacterium ulcerans infection.
abstract: BACKGROUND
  Antimicrobial killing in mycobacterial infections may be accompanied by (transient) clinical deterioration, known as paradoxical reaction. To search for patterns reflecting such reactions in the treatment of Buruli ulcer (Mycobacterium ulcerans infection), the evolution of lesions of patients treated with antimicrobials was prospectively assessed.
  
  
  METHODS
  The lesion size of participants of the BURULICO antimicrobial trial (with lesions ≤10 cm cross-sectional diameter) was assessed by careful palpation and recorded by serial acetate sheet tracings. Patients were treated with antimicrobials for 8 weeks. For the size analysis, participants whose treatment had failed, had skin grafting, or were coinfected with human immunodeficiency virus were excluded. For every time point, surface area was compared with the previous assessment. A generalized additive mixed model was used to study lesion evolution. Nonulcerative lesions were studied using digital images recording possible subsequent ulceration.
  
  
  RESULTS
  Of 151 participants, 134 were included in the lesion size analysis. Peak paradoxical response occurred at week 8; >30% of participants showed an increase in lesion size as compared with the previous (week 6) assessment. Seventy-five of 90 (83%) of nonulcerative lesions ulcerated after start of treatment. Nine participants developed new lesions during or after treatment. All lesions subsequently healed.
  
  
  CONCLUSIONS
  After start of antimicrobial treatment for Buruli ulcer, new or progressive ulceration is common before healing sets in. This paradoxical response, most prominent at the end of the 8-week antimicrobial treatment, should not be misinterpreted as failure to respond to treatment. Clinical Trials Registration. ClinicalTrials.gov, NCT00321178.
authors.affiliation: Department of Internal Medicine, Infectious Diseases Service and Tuberculosis Unit, University Medical Center Groningen, University of Groningen, The Netherlands.
authors.forename: Willemien A
authors.initials: WA
authors.lastname: Nienhuis
authors.forename: Ymkje
authors.initials: Y
authors.lastname: Stienstra
authors.forename: K Mohammed
authors.initials: KM
authors.lastname: Abass
authors.forename: Wilson
authors.initials: W
authors.lastname: Tuah
authors.forename: William A
authors.initials: WA
authors.lastname: Thompson
authors.forename: Peter C
authors.initials: PC
authors.lastname: Awuah
authors.forename: Nana Yaa
authors.initials: NY
authors.lastname: Awuah-Boateng
authors.forename: Ohene
authors.initials: O
authors.lastname: Adjei
authors.forename: Gisela
authors.initials: G
authors.lastname: Bretzel
authors.forename: Jan P
authors.initials: JP
authors.lastname: Schouten
authors.forename: Tjip S
authors.initials: TS
authors.lastname: van der Werf
mesh_terms: D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D054312:Buruli Ulcer / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology*; D002648:Child; D005260:Female; D006678:HIV; D006801:Humans; D008297:Male; D019911:Mycobacterium ulcerans / Q000302:isolation & purification*; D011446:Prospective Studies; D012867:Skin / Q000473:pathology; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents