Malassezia Dermatitis Flashcards
Malassezia pachydermatitis
- Non-obligatory, lipophilic yeast organism
- Broad-based, budding, round to oval to peanut-shaped organism
- Considered a normal inhabitant of canine skin
pathogenic factors associated with an infection
Environment: Humidity, temperature
Immune function: age, immunosuppressive disease
Breeds: basset hound, boxer, etc.
concurrent disease: Atopy
Diseases associated with Malassezia Dermatitis
- Allergies: atopy, adverse reactions to food, flea allergy
- Endocrinopathies: hy[pthyroidism, hyperadrenocorticism, diabetes mellitus
- Disorders of cornification: seborrhea, “epidermal dysplasia” of WHWT
- Systemic illness: liver disease, renal disease
Pathogenic mechanisms of Malassezia pachydermatitis
- Activation of alternative pathoway of complement
- Hypersensitivity to fungal allergens
- Produces proteases, zymosan and other substances that contribute to inflammation and pruritus
- Symbiotic relationship with staphylococci
historical features associated with a Malassezia pachydermatitis infections
severe, progressive pruritus
Partially responsive to glucocorticoids
Historical complaints: licking feet, rubbing face, perianal pruritus, otitis externa, weight loss
appear to be an atopy case out of control
what are differentials for severe pruritus
Scabies
Malassezia dermatitis
Flea allergy dermatitis
Familial seborrhea or combinations of several mildly-moderately pruritic conditions
What are key physical features of Malassezia Pachydermatitis infections
- Severe pruritus
- Erythematous scaling and crusting dermatitis early
- Lichenified, hyperplastic, hyperpigmented skin
- Alopecia reflects severity of pruritus
- Generalized enlarged lymph nodes
- yeast otitis
what are some trouble spots for Malassezia infections
facial folds
lip folds
claw folds
tops and bottoms of feet
diagnosis of Malassezia pachydermatitis infection
dermatologic history
Physical and dermatologic examinations
Derm database
Allergy testing
CBC, chem profile
What is the scale used to quantify quantify the severity of Malassezia infection
0-4
controling the bacterial infection associated with Malassezia pachydermitis infections
commonly associated with the primary conditions (atopy)
Specific therapy
- topical antibacterial agents BPO
- Anti-staphylococcal antibiotics
topical therapy associated with Malassezia pachydermatitis infections
Effective active ingredients: selenium disulfide, chlorhexidine, miconazole, lime sulfur
Frequency of applications depends on:
- severity of disease
- location of infection
- owner compliance
shampoo therapies assoicated with Malassezia Pachydermatitis infections
selenium sulfide used to reduce greasiness
specific antifungal used to clear the yeast
Keys to therapy:
- contact time
- Use look-cool water to decrease the pruritus
- once a week is adequate when combined with another topical therapy
- May alternate with an anti-bacterial shampoo
What is the benefit of Azole + Chlorhexidine shampoos in Malassezia pachydermatitis infection
combination of these drugs appear to be synergistic. Double duty getting rid of both stapy and yeast
systemic Antifungal therapy
ketoconazole, itraconazole, fluconazole, terbinafine
Indications (strongly encourage topical products)
- owners can’t bathe or manage topicals
- severe infections
- cutaneous and toic infections
Duration of treatment 21-30 days
Monitor with scrapings or impressions
Treat until 0-1+ findings
