title: Onychomycosis in systemic lupus erythematosus: a case control study.
abstract: OBJECTIVE
  Immunosuppressed patients are prone to develop onychomycosis. In systemic lupus erythematosus (SLE) there are no previous studies. We aimed to establish the prevalence, clinical characteristics, and organisms causing onychomycosis in SLE patients compared with controls.
  
  
  METHODS
  Fifty consecutive patients with SLE seen on an outpatient basis and 50 sex and age matched controls. Samples were obtained when abnormal nails were found: distal and lateral subungual onychomycosis (DLSO), white superficial, proximal subungual (PSO), endonyx, and total dystrophic (TDO). The nail specimens were evaluated in a blinded fashion, by mycologic examination and culture.
  
  
  RESULTS
  Of the SLE patients, there were 12 (24%) with onychomycosis confirmed. The distribution of the clinical forms were TDO 6/12 (50%), DLSO 4/12 (33%), and PSO 2/12 (17%). The causative organisms were isolated in 6 cases: Trichophyton rubrum 3/6 (50%), Trichophyton mentagrophytes 2/6 (33%), Microsporum canis 1/6 (17%). Direct microscopy examination revealed fungal elements in the other 6 cases. Of the 50 controls, 4 (8%) presented onychomycosis [p = 0.029; OR 3.63 (95% CI 1.04-14.68)]: DLSO 2/4 (50%), and TDO 2/4 (50%). Trichophyton rubrum was isolated in 1 and Trichophyton mentagrophytes in 1 (50%).
  
  
  CONCLUSIONS
  These data suggest a higher prevalence of onychomycosis in SLE versus controls, the predominant organism was Trichophyton rubrum, an anthropophilic dermatophyte. Toenails were more frequently affected and the most common clinical presentation was TDO. PSO, a rare pattern in immunocompetent subjects, was exclusively found in the lupus group.
authors.affiliation: Unidad de Investigación Médica en Epidemiología Clínica, Centro Médico Nacional de Occidente, Instituto Mexicano del Seguro Social, Guadalajara, Jalisco, Mexico. albtlacuilo@yahoo.com
authors.forename: Alberto
authors.initials: A
authors.lastname: Tlacuilo-Parra
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Guevara-Gutierrez
authors.forename: Jorge
authors.initials: J
authors.lastname: Mayorga
authors.forename: Ignacio
authors.initials: I
authors.lastname: Garcia-De La Torre
authors.forename: Mario
authors.initials: M
authors.lastname: Salazar-Paramo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D005533:Foot Dermatoses / Q000453:epidemiology / Q000382:microbiology / Q000473:pathology; D005658:Fungi / Q000302:isolation & purification; D006801:Humans; D016867:Immunocompromised Host; D008180:Lupus Erythematosus, Systemic / Q000150:complications / Q000453:epidemiology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D014009:Onychomycosis / Q000453:epidemiology* / Q000382:microbiology / Q000473:pathology; D015995:Prevalence