title: Food allergy in South African children with atopic dermatitis.
abstract: BACKGROUND
  The prevalence of food allergy in South Africa is unknown, but previously thought to be rare in black South Africans. This study aimed to determine the prevalence of, and risk factors for, IgE-mediated food allergy in South African children with atopic dermatitis (AD).
  
  
  METHODS
  This was a prospective, observational study in a paediatric university hospital in Cape Town. Children with AD, aged 6 months to 10 yrs, were randomly recruited from the dermatology clinic. They were assessed for sensitization and allergy by questionnaire, skin prick tests, Immuno Solid Phase Allergen Chip (ISAC) test and incremental food challenges.
  
  
  RESULTS
  100 participants (59 black Africans and 41 of mixed race) were enrolled, median age 42 months. There were high overall rates of food sensitization (66%) and food allergy (40%). Egg (25%) and peanut (24%) were the most common allergies. Black participants had comparable sensitization (69% vs. 61%) but lower allergy rates (34% vs. 46%) than mixed race participants. This was especially evident for peanut allergy (15% Blacks vs. 37% mixed race allergic to peanut, p = 0.01). Early-onset AD (<6 months), severe eczema, and young age <2 yrs were significant risk factors for food allergy.
  
  
  CONCLUSIONS
  The prevalence of food allergy is unexpectedly high in South African children with AD, and comparable with food allergy rates in patients with AD in developed countries. There are ethnic differences, with significantly lower peanut allergy rates in Blacks compared to mixed race patients. These results are not generalizable to an unselected South African population, which requires further study.
authors.affiliation: Division of Allergology, Red Cross War Memorial Children's Hospital, Cape Town, South Africa.
authors.forename: Claudia L
authors.initials: CL
authors.lastname: Gray
authors.forename: Michael E
authors.initials: ME
authors.lastname: Levin
authors.forename: Heather J
authors.initials: HJ
authors.lastname: Zar
authors.forename: Paul C
authors.initials: PC
authors.lastname: Potter
authors.forename: Nonhlanhla P
authors.initials: NP
authors.lastname: Khumalo
authors.forename: Lucia
authors.initials: L
authors.lastname: Volkwyn
authors.forename: Bartha
authors.initials: B
authors.lastname: Fenemore
authors.forename: George
authors.initials: G
authors.lastname: du Toit
mesh_terms: D017668:Age of Onset; D000485:Allergens / Q000276:immunology; D010367:Arachis / Q000276:immunology; D044383:Black People; D002648:Child; D002675:Child, Preschool; D003876:Dermatitis, Atopic / Q000150:complications / Q000453:epidemiology*; D005260:Female; D005512:Food Hypersensitivity / Q000150:complications / Q000453:epidemiology*; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D007223:Infant; D008297:Male; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D012882:Skin Tests; D013019:South Africa
chemical_list: D000485:Allergens; D007073:Immunoglobulin E
keywords: IgE-mediated; atopic dermatitis; black Africans; food allergy; food sensitization; incremental food challenges; peanut allergy