title: Characterization of the polysensitized patient: a matched case-control study.
abstract: BACKGROUND
  Polysensitization ( >or= 3 contact allergies) may be regarded as a special entity in patients with contact allergies. However, this group of polysensitized patients is poorly characterized. Filaggrin mutations are associated with atopic eczema and lead to impaired skin barrier which may predispose to contact allergy. Therefore, it is of interest to consider atopic eczema and contact allergies, especially in patients with multiple allergies.
  
  
  OBJECTIVE
  To characterize polysensitized patients regarding occurrence, duration and course of dermatitis, and examine potential risk factors for polysensitization, including atopic eczema.
  
  
  METHODS
  A questionnaire case-control study of 562 polysensitized and 1124 single/double-sensitized individuals was performed.
  
  
  RESULTS
  The results show that 45% of polysensitized and 31% of single/double-sensitized patients had or had had atopic eczema, and atopic eczema was identified as a risk factor for polysensitization. Patients with leg ulcer constituted only a minor part of the polysensitized group and leg ulcers were not identified as a risk factor for polysensitization in this study. The influence of contact allergies on duration and course of disease diverged between the group of patients with atopic eczema and the group without atopic eczema.
  
  
  CONCLUSIONS
  Patients with atopic eczema were overrepresented in the group of polysensitized patients and polysensitized patients should be viewed in the light of occurrence or lack of atopic eczema.
authors: Department of Dermatology and Allergology, National Allergy Research Centre, Copenhagen University Hospital Gentofte, 2900 Hellerup, Denmark. bccarlsen@dadlnet.dk
authors: Berit Christina
authors: BC
authors: Carlsen
authors: Klaus Ejner
authors: KE
authors: Andersen
authors: Torkil
authors: T
authors: Menné
authors: Jeanne Duus
authors: JD
authors: Johansen
mesh_terms: D016022:Case-Control Studies; D003718:Denmark / Q000453:epidemiology; D017449:Dermatitis, Allergic Contact / Q000453:epidemiology*; D003876:Dermatitis, Atopic / Q000453:epidemiology*; D005260:Female; D000091344:Filaggrin Proteins; D006801:Humans; D007871:Leg Ulcer / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D016555:Matched-Pair Analysis; D008875:Middle Aged; D018777:Multiple Chemical Sensitivity / Q000453:epidemiology*; D015999:Multivariate Analysis; D012307:Risk Factors