title: Onychomycosis: a simpler in-office technique for sampling specimens.
abstract: BACKGROUND
  In onychomycosis, proper specimen collection is essential for an accurate diagnosis and initiation of appropriate therapy. Several techniques and locations have been suggested for specimen collection.
  
  
  OBJECTIVE
  To investigate the optimal technique of fungal sampling in onychomycosis.
  
  
  METHODS
  We reexamined 106 patients with distal and lateral subungual onychomycosis (DLSO) of the toenails. (The diagnosis had previously been confirmed by a laboratory mycological examination—both potassium hydroxide [KOH] test and fungal culture—of samples obtained by the proximal sampling approach.) We collected fungal specimens from the distal nail bed first, and later from the distal underside of the nail plate. The collected specimens underwent laboratory mycological examination.
  
  
  RESULTS
  KOH testing was positive in 84 (79.2%) specimens from the distal nail bed and only in 60 (56.6%) from the distal underside of the nail plate (P=.0007); cultures were positive in 93 (87.7%) and 76 (71.7%) specimens, respectively (P=.0063). Combining results from both locations showed positive KOH test results in 92 (86.8%) of the 106 patients and positive cultures in 100 (94.3%) patients.
  
  
  CONCLUSIONS
  Based on our study, we suggest that in cases of suspected DLSO, material should be obtained by scraping nail material from the distal underside of the nail and then collecting all the material from the distal part of the nail bed.
authors.affiliation: Department of Dermatology, Sheba Medical Center, Tel-Hashomer, Israel.
authors.forename: Avner
authors.initials: A
authors.lastname: Shemer
authors.forename: Batya
authors.initials: B
authors.lastname: Davidovici
authors.forename: Marcelo H
authors.initials: MH
authors.lastname: Grunwald
authors.forename: Anna
authors.initials: A
authors.lastname: Lyakhovitsky
authors.forename: Boaz
authors.initials: B
authors.lastname: Amichai
mesh_terms: D003883:Arthrodermataceae / Q000302:isolation & purification*; D001706:Biopsy / Q000379:methods / Q000706:statistics & numerical data; D003627:Data Interpretation, Statistical; D006801:Humans; D006878:Hydroxides; D016533:Mycological Typing Techniques / Q000706:statistics & numerical data; D009262:Nails / Q000473:pathology*; D014009:Onychomycosis / Q000175:diagnosis / Q000382:microbiology; D017680:Potassium Compounds; D015203:Reproducibility of Results
chemical_list: D006878:Hydroxides; D017680:Potassium Compounds; C029943:potassium hydroxide