title: The significance of allergic contact urticaria to milk in children with cow's milk allergy.
abstract: BACKGROUND
  Cow's milk allergy (CMA) is the most common food allergy in infancy. Food allergy is generally triggered through ingestion, but can also be triggered through skin contact. We investigated the incidence and the clinical significance of cow's milk protein (CMP)-induced contact urticaria in individuals with CMA with and without atopic dermatitis (AD).
  
  
  METHODS
  A total of 157 children of whom 133 were diagnosed with CMA were participated. The study was based on observational data gathered in the course of patient care, including a skin prick test and a 'finger test', in which cow's milk is applied on the cheek by a physician's finger to detect contact urticaria.
  
  
  RESULTS
  Eighty nine of 133 patients (66.9%) had IgE-mediated CMA. Forty of these 89 (44.9%) tested positive in the finger test. Family atopy was higher in those with positive contact urticaria [21/40 (52.5%) vs. 14/49 (28.5%), p = 0.029]. Patients with positive vs. negative CMP contact urticaria had higher incidence of multiple food allergies [20 of 40 (50%) vs. 7/49 (14.3%), p < 0.004]. IgE-mediated CMA patients with AD had statistically higher CMP allergic contact urticaria compared to patients without AD [71% (15/21) vs. 37% (25/68), p = 0.0064]. Children with non-IgE milk allergy and healthy control group did not have contact urticaria to CMP.
  
  
  CONCLUSIONS
  CMP contact urticaria exists only in patients with IgE-mediated CMA. A 'finger test' to CMP should be part of the evaluation of CMA patients, and positivity suggests the potential for multiple food allergies, especially to sesame and egg.
authors.affiliation: Division of Allergy & Clinical Immunology, Bnai-Zion Medical Center, Rappaport Faculty of Medicine, Technion, Haifa, Israel.
authors.forename: Vered
authors.initials: V
authors.lastname: Schichter-Konfino
authors.affiliation: Division of Allergy & Clinical Immunology, Bnai-Zion Medical Center, Rappaport Faculty of Medicine, Technion, Haifa, Israel.
authors.forename: Meital
authors.initials: M
authors.lastname: Almog
authors.affiliation: Pediatric Department, Bnai-Zion Medical Center, Rappaport Faculty of Medicine, Technion, Haifa, Israel.
authors.forename: Ellen
authors.initials: E
authors.lastname: Bamberger
authors.affiliation: Pediatric Gastroenterology Unit, Bnai-Zion Medical Center, Rappaport Faculty of Medicine, Technion, Haifa, Israel.
authors.forename: Drora
authors.initials: D
authors.lastname: Berkowitz
authors.affiliation: Division of Allergy & Clinical Immunology, Bnai-Zion Medical Center, Rappaport Faculty of Medicine, Technion, Haifa, Israel.
authors.forename: Aharon
authors.initials: A
authors.lastname: Kessel
mesh_terms: D002675:Child, Preschool; D003429:Cross Reactions; D017449:Dermatitis, Allergic Contact / Q000150:complications / Q000453:epidemiology* / Q000276:immunology; D003876:Dermatitis, Atopic / Q000150:complications / Q000453:epidemiology* / Q000276:immunology; D003955:Diagnostic Tests, Routine; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D015994:Incidence; D007223:Infant; D007557:Israel; D008297:Male; D016269:Milk Hypersensitivity / Q000150:complications / Q000453:epidemiology* / Q000276:immunology; D012882:Skin Tests; D014581:Urticaria / Q000150:complications / Q000453:epidemiology* / Q000276:immunology
chemical_list: D007073:Immunoglobulin E
keywords: atopic dermatitis; contact urticaria; milk allergy