Cow's milk casein, a hidden allergen in natural rubber latex gloves

J Allergy Clin Immunol. 1999 Jul;104(1):177-80. doi: 10.1016/s0091-6749(99)70131-4.


Background: We have previously noted that one natural rubber latex (NRL) glove brand used for skin prick testing in the diagnosis of NRL allergy contained cow's milk casein.

Objective: We sought to examine whether other commonly marketed NRL glove brands contain cow's milk casein.

Methods: The casein content of 30 NRL glove extracts (1:5 wt/vol) was measured by RAST inhibition and by rocket immunoelectrophoresis and rocket radioimmunoelectrophoresis by using casein-specific rabbit antiserum, a serum pool from patients with cow's milk allergy, and radiolabeled anti-human IgE. The NRL allergen content was measured by ELISA inhibition.

Results: The casein content of the glove used in NRL allergy screening (Triflex, Baxter) was rather high (ie, about 400 microgram/g of glove). Its total protein content was 1000 microgram/g of glove. Rocket radioimmunoelectrophoresis detected distinct amounts of casein in 8, minimal amounts in 7, and no casein in the remaining 15 NRL glove brands.

Conclusions: Several brands of NRL gloves were found to contain casein, implying that extracts prepared from such gloves can cause false-positive skin prick test reactions when diagnosing NRL allergy. The use of casein as a stabilizer in glove manufacture without appropriate labeling should be stopped because it can also cause contact urticaria syndrome in individuals with cow's milk allergy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Allergens / analysis*
  • Caseins / analysis
  • Caseins / immunology*
  • Child
  • Child, Preschool
  • False Positive Reactions
  • Female
  • Gloves, Protective*
  • Humans
  • Infant
  • Latex Hypersensitivity / diagnosis
  • Latex Hypersensitivity / immunology*
  • Male
  • Milk Hypersensitivity / immunology*
  • Proteins / analysis
  • Radioallergosorbent Test
  • Skin Tests


  • Allergens
  • Caseins
  • Proteins