Type-1 hypersensitivity reactions to Malassezia pachydermatis extracts in atopic dogs.

Abstract

OBJECTIVE:

To investigate the potential allergenic role of the yeast Malassezia pachydermatis in dogs with clinical diagnosis of atopic dermatitis.

ANIMALS:

5 clinically normal nonatopic dogs, 10 atopic dogs with cytologic evidence of Malassezia dermatitis, and 12 atopic dogs without cytologic evidence of Malassezia dermatitis.

PROCEDURE:

A crude yeast extract was produced by disrupting the cell wall of M pachydermatis. The crude extract and 8 of its fractions, which were generated by fractionation in a high-performance liquid chromatography column, were injected along with 46 commercial allergens for intradermal allergy testing of normal and atopic sample populations. Significant difference between atopic populations was evaluated, using a threshold concentration of crude yeast extract that failed to induce wheal-and-flare responses in normal nonatopic dogs.

RESULTS:

Atopic dogs with cytologic evidence of Malassezia dermatitis had significantly greater wheal-and-flare reactions to intradermal injection of crude extract of M pachydermatis than did atopic dogs without cytologic evidence of Malassezia dermatitis.

CONCLUSIONS:

It is concluded that M pachydermatis is capable of promoting type-1 hypersensitivity reactions in dogs with an atopic dermatitis phenotype.

CLINICAL RELEVANCE:

Currently, Malassezia dermatitis is principally managed by use of antifungal chemotherapy. Because the yeast appears to be a contributing allergen in dogs with atopic dermatitis, hyposensitization with M pachydermatis extracts may offer a future alternative to extended or repeated episodic administration of antifungals for extended control of recurrent infections.

• Authors: D O Morris, N B Olivier, E J Rosser
• Journal: American journal of veterinary research (Am J Vet Res) Vol. 59 Issue 7 Pg. 836-41 (Jul 1998) ISSN: 0002-9645 [Print] United States
• PMID: 9659547 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Allergens
• Antigens, Fungal

Topics

• Allergens
• Animals
• Antigens, Fungal (immunology)
• Dermatitis, Atopic (immunology, veterinary)
• Dog Diseases (immunology)
• Dogs
• Hypersensitivity
• Malassezia (immunology)
• Skin Tests (veterinary)