Dermatology - Malassezia Dermatitis Flashcards Preview

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Flashcards in Dermatology - Malassezia Dermatitis Deck (43)
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1

Describe Malassezia pachydermatis (i.e what type of fungi and where it lives).

It is a non-obligatory, lipophilic, budding yeast considered part of the normal flora of the skin and external ear canal

2

Malassezia infections are almost always _____ _____.

secondary conditions - perpetuating factors of pruritus

3

What are the typical underlying causes associated with Malassezia infections?

atopy, other allergic skin diseases, endocrine imbalances, systemic illness, immunodeficiency syndromes, including glucocorticoid administration, nutritional deficiencies

4

What are predisposing factors to Malassezia infections?

breed, presence of seborrheic dermatitis, increased temperature, increased humidity, and immunodeficiency conditions

5

What is the pathogenesis of Malassezia infections?

1. Activation of the alternate pathway of complement
2. Production of enzymes and toxins that induce inflammation
3. Hypersensitivity reactions
4. Synergistic actions with Staph. Pseudintermedius

6

What breeds are predisposed to Malassezia infections?

Chinese shar-pei, basset hound, american cocker spaniel, boxer, dachshund, and labrador retriever

7

What is the main historical feature associated with Malassezia infections?

intense pruritus

8

What other historical features are associated with Malassezia infections?

History of licking feet, rubbing face, generalized pruritus that initially responded to glucocorticoid therapy, but then becomes less and less responsive - they appear to be an atopy case of of control

9

What physical findings are associated with Malassezia infections in the exam room?

Intense pruritus, scratching and biting in the exam room

10

How do lesions appear in cases of Malassezia infections?

They begin as erythema and scaling, then progress to alopecia, lichenification, and hyperpigmentation

11

What does the skin and hair coat look like in patients with Malassezia infections?

it appears greasy and malodorous

12

What clinical condition, aside from the intense pruritus is commonly seen in patients that have Malassezia infections?

otitis externa

13

How do the peripheral lymph nodes present in patients with Malassezia infections?

they are enlarged and prominent

14

When diagnosing Malassezia infections, what should be done first?

You need to identify the primary factor

15

What are the recommended diagnostic procedures for identifying the primary factor in Malassezia cases?

history, PE, dermatology data base, allergy tests, tests to evaluate for endocrine disease, routine hematology

16

How are yeast infections confirmed?

Impression smears of affected skin, using adhesive tape, clean glass microscope slides, or slides with adhesive

17

What is a 0 on Dr. Noxon's subjective Malassezia scale?

no yeast on slide

18

What is a 1 on Dr. Noxon's subjective Malassezia scale?

few yeast on slide (1-4)

19

What is a 2 on Dr. Noxon's subjective Malassezia scale?

several yeast on slide (5-12)

20

What is a 3 on Dr. Noxon's subjective Malassezia scale?

one organism seen every 2-4 high dry or oil immersion fields

21

What is a 4 on Dr. Noxon's subjective Malassezia scale?

one or more yeast found per microscope field

22

What grade on the scale warrants therapy?

a 2+ or greater

23

In patients with Malassezia infections, what will a skin biopsy show?

hyperplastic dermatitis, with orthokeratotic hyperkeratosis, superficial perivascular dermatitis, with varying degrees of crusts

24

How is Malassezia managed (generally)?

control concurrent bacterial dermatitis, treat the yeast infection, identify and control the preliminary disease

25

What treatments can be used to treat Malassezia infections?

Systemic antifungals, shampoos, and some other topical treatments

26

Can shampoos be used as the sole treatment for Malassezia infections?

yes, but they can also be used in conjunction with systemic therapy

27

Selsun Blue, the human dandruff shampoo can be used to treat Malassezia infections, what effective ingredient is in it?

selenium disulfide

28

What effective ingredients are in Nizoral or KetoChlor shampoos?

salicylic acid and ketoconazole

29

What effective ingredient is in Dermazole, miconazole Shampoo, or MalaSeb shampoos?

miconazol

30

What effective ingredient is in Hexidien shampoo?

chlorhexidine

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