Sex difference in Fel d 1 allergen production

J Allergy Clin Immunol. 1996 Jul;98(1):165-8. doi: 10.1016/s0091-6749(96)70238-5.


Background: Previous experiments have shown that in vivo Fel d 1 production is under hormonal control. It strongly decreased 1 month after castration of male cats and increased after testosterone injection.

Objective: These results led us to put forward the hypothesis that Fel d 1 production could be more important in male that in female cats. Five adult male and five adult female cats were studied.

Methods: On day 0 three separate sites of each cat's trunk were shaved, and a 5.72 cm2 area in each site was washed twice (D0a and D0b) with 5 ml of distilled water. Then a collar was attached to the neck to prevent contamination from saliva. Twenty-four hours later on day 1, all areas were washed again once (D1a). Skin washes and fur extracts from the shaved areas were evaluated for Fel d 1 content. The same procedures (apart from collection of fur) were repeated 5 months later.

Results: The Fel d 1 level was higher in the first skin wash of male cats compared with that of female cats on each separate site of the trunk in both experiments, initially and 5 months later. Results were significant in the first experiment (median Fel d 1 per milliliter: 69.4 and 28.9 mU, respectively, for the combined three sites; p < 0.05). Fel d 1 production over a 24-hour period was higher in male cats, but the difference did not reach statistical significance. Furthermore, correlation between Fel d 1 levels in washes D0a and in fur was highly significant (p < 0.01).

Conclusion: These results confirm that Fel d 1 originates from skin. Furthermore, they suggest that Fel d 1 production is higher in male than in female cats.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Allergens / biosynthesis*
  • Animals
  • Cats
  • Female
  • Glycoproteins / biosynthesis*
  • Hair / immunology
  • Male
  • Sex Characteristics*
  • Skin / immunology


  • Allergens
  • Glycoproteins
  • Fel d 1 protein, Felis domesticus