Difference between revisions of "Malassezia Dermatitis"

Latest revision as of 13:31, 23 August 2015

Introduction

Malasseszia Dermatitis is a skin disease associated with the yeast Malassezia pachydermatis. It is common in dogs but rare in cats. The yeast is found on skin and mucosal sites in healthy dogs and cats and under circumstances which remain poorly understood can proliferate and induce skin disease.

Pathogenesis

Malassezia pachydermatis proliferates and liberates enzymes and metabolites which induce cutaneous inflammation. Concurrent skin diseases such as atopic dermatitis and primary defects of keratinisation are recognised in approximately 66% of cases. Some dogs may show hypersensitivity to Malassezia pachydermatis.

Signalment

Basset hounds, Cocker Spaniels and West Highland Terriers are predisposed.

History

Affected dogs usually present with a greasy skin disease often with a characteristic odour and a variable degree of pruritus.

Clinical signs

Malassezia dermatitis can complicate or mimic allergic skin disease and scaling skin disorders. The main clinical signs are erythema and a greasy exudate which may result in matted hair with variable amounts of alopecia and scaling. Hyperpigmentation, lichenification and follicular plugging occur in chronic cases. Concurrent erythematous otitis externa with variable ceruminous discharge is common. The degree of pruritus is variable but can be extreme especially on the face in a small number of dogs.

Laboratory tests

The most common method of diagnosis is by microscopic examination of a tape strip revealing an increased number of Malassezia pachydermitis. Clear adhesive tape is applied to the affected area and removed, stained and examined under oil immersion. The yeast can also be cultured on Sabrouraud's dextrose agar at 32-37°C for 3-5 days.

Treatment

Treatment is aimed at reducing the yeast population and treating any underlying skin conditions. The first choice of treatment is an antifungal medicated shampoo containing miconazole and chlorhexidine. Selenium sulphide in combination with enilconazole or ketoconazole can also be used topically but is less effective. The use of systemic antifungal drugs such as ketoconazole can also be considered. The response to treatment should be measured by clinical response and by a reduction in yeast populations in skin lesions upon microscopic examination.

Malassezia Dermatitis Learning Resources
Vetstream To reach the Vetstream content, please select	Canis, Felis, Lapis or Equis
Flashcards Test your knowledge using flashcard type questions	Small Animal Dermatology Q&A 08
Literature Search Search for recent publications via CAB Abstract (CABI log in required)	Malassezia Dermatitis publications
Full Text Articles Full text articles available from CAB Abstract (CABI log in required)	How I treat Malassezia dermatitis. Ghubash, R.; The North American Veterinary Conference, Gainesville, USA, Small animal and exotics. Proceedings of the North American Veterinary Conference, Orlando, Florida, USA, 17-21 January, 2009, 2009, pp 328-329 How I treat Malassezia dermatitis. Rosenkrantz, W.; The North American Veterinary Conference, Gainesville, USA, Small animal and exotics. Proceedings of the North American Veterinary Conference, Orlando, Florida, USA, 17-21 January, 2009, 2009, pp 392-393, 5 ref. Malassezia dermatitis: diagnosis & management. Ihrke, P. J.; Gething, M.; Jones, B.; Australian Small Animal Veterinary Association, Bondi, Australia, 33rd World Small Animal Veterinary Association Congress, Dublin, Ireland, 20-24 August 2008, 2008, pp 169-171, 5 ref.

References

Merck & Co (2008) The Merck Veterinary Manual (Eighth Edition) Merial
Foster, A, and Foll, C. (2003) BSAVA small animal dermatology (second edition) British Small Animal Veterinary Association
Bond, R, Hendricks, A. (2008) Veterinary Dermatology Integrated BVetMed course notes Department of Veterinary Clinical Sciences and Pathology and Infectious Disease. Royal Veterinary College, University of London.

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@@ Line 1: / Line 1: @@
-*Caused by [[Malassezia pachydermidis|''Malassezia pachydermatis'']]
+{{OpenPagesTop}}
-*Yeast, normally present in external ear canal and skin
+==Introduction==
-*Clinical disease may cause yeast to proliferate and cause infection
+Malasseszia Dermatitis is a skin disease associated with the yeast [[Malassezia pachydermatis|''Malassezia pachydermatis'']]. It is common in dogs but rare in cats. The yeast is found on skin and mucosal sites in healthy dogs and cats and under circumstances which remain poorly understood can proliferate and induce skin disease.
-*Grossly:
-**Regional lesions: muzzle, ears, interdigital, perianal
-**Or generalised disease
-**Erythematous, hyperpigmented, [[Skin Glossary - Pathology|lichenified]] and scaly lesions with alopecia
-*Microscopically:
-**[[Skin Glossary - Pathology|hyperkeratosis, parakeratosis]]
-**Spongiotic pustular dermatitis
-**[[Skin Glossary - Pathology|Acanthosis]]
-**Organisms are usually present, minimum 3-5 yeasts per high-power field must be found to imply cause of disease
+==Pathogenesis==
+''Malassezia pachydermatis'' proliferates and liberates enzymes and metabolites which induce cutaneous inflammation. Concurrent skin diseases such as [[Atopic Dermatitis|atopic dermatitis]] and primary defects of keratinisation are recognised in approximately 66% of cases. Some dogs may show hypersensitivity to ''Malassezia pachydermatis''.
-Grossly, regional lesions may be seen around the muzzle, [[Ear -  Anatomy & Physiology|ears]], interdigital, and perianal.  Other  common signs include erythema, hyperpigmentation, [[Skin Glossary -  Pathology|lichenified]] and scaly lesions with alopecia.
+==Signalment==
+Basset hounds, Cocker Spaniels and West Highland Terriers are predisposed.
-Microscopically,  one may see;[[Skin Glossary - Pathology|hyperkeratosis,  parakeratosis]], spongiotic pustular dermatitis, [[Skin Glossary -  Pathology|Acanthosis]].
+==History==
+Affected dogs usually present with a greasy skin disease often with a characteristic odour and a variable degree of pruritus.
+==Clinical signs==
+Malassezia dermatitis can complicate or mimic allergic skin disease and scaling skin disorders. The main clinical signs are '''erythema and a greasy exudate''' which may result in matted hair with variable amounts of alopecia and scaling. Hyperpigmentation, lichenification and follicular plugging occur in chronic cases. Concurrent erythematous otitis externa with variable ceruminous discharge is common.
+The degree of pruritus is variable but can be extreme especially on the face in a small number of dogs.
+==Laboratory tests==
+The most common method of diagnosis is by microscopic examination of a tape strip revealing an increased number of ''Malassezia pachydermitis''. Clear adhesive tape is applied to the affected area and removed, stained and examined under oil immersion. The yeast can also be cultured on Sabrouraud's dextrose agar at 32-37°C for 3-5 days.
+==Treatment==
+Treatment is aimed at reducing the yeast population and treating any underlying skin conditions. The first choice of treatment is an antifungal medicated '''shampoo containing miconazole and chlorhexidine'''. Selenium sulphide in combination with enilconazole or ketoconazole can also be used topically but is less effective. The use of systemic antifungal drugs such as ketoconazole can also be considered. The response to treatment should be measured by clinical response and by a reduction in yeast populations in skin lesions upon microscopic examination.
+{{Learning
+|Vetstream = [https://www.vetstream.com/canis/Content/Disease/dis00126.asp Malassezia dermatitis]<br>[https://www.vetstream.com/canis/Content/Bug/bug00277.asp Malassezia pachydermatis]
+|flashcards = [[Small Animal Dermatology Q&A 08]]
+|literature search = [http://www.cabdirect.org/search.html?rowId=1&options1=AND&q1=malassezia&occuring1=title&rowId=2&options2=AND&q2=dermatitis&occuring2=title&rowId=3&options3=AND&q3=&occuring3=freetext&x=51&y=13&publishedstart=yyyy&publishedend=yyyy&calendarInput=yyyy-mm-dd&la=any&it=any&show=all Malassezia Dermatitis publications]
+|full text = [http://www.cabi.org/cabdirect/FullTextPDF/2009/20093115170.pdf '''How I treat Malassezia dermatitis'''. Ghubash, R.; The North American Veterinary Conference, Gainesville, USA, Small animal and exotics. Proceedings of the North American Veterinary Conference, Orlando, Florida, USA, 17-21 January, 2009, 2009, pp 328-329]
+[http://www.cabi.org/cabdirect/FullTextPDF/2009/20093115083.pdf ''' How I treat Malassezia dermatitis'''. Rosenkrantz, W.; The North American Veterinary Conference, Gainesville, USA, Small animal and exotics. Proceedings of the North American Veterinary Conference, Orlando, Florida, USA, 17-21 January, 2009, 2009, pp 392-393, 5 ref.]
+[http://www.cabi.org/cabdirect/FullTextPDF/2009/20093017851.pdf '''Malassezia dermatitis: diagnosis & management'''. Ihrke, P. J.; Gething, M.; Jones, B.; Australian Small Animal Veterinary Association, Bondi, Australia, 33rd World Small Animal Veterinary Association Congress, Dublin, Ireland, 20-24 August 2008, 2008, pp 169-171, 5 ref.]
+}}
+==References==
+* Merck & Co (2008) '''The Merck Veterinary Manual (Eighth Edition)''' ''Merial''
+* Foster, A, and Foll, C. (2003) '''BSAVA small animal dermatology (second edition)''' '' British Small Animal Veterinary Association''
+* Bond, R, Hendricks, A. (2008) '''Veterinary Dermatology Integrated BVetMed course notes''' Department of Veterinary Clinical Sciences and Pathology and Infectious Disease. Royal Veterinary College, University of London.
+{{review}}
+{{OpenPages}}
+[[Category:Expert Review]]
+[[Category:Dermatological Diseases - Dog]]
+[[Category:Cutaneous Mycoses]]