Lecture: Keratinization disorders/seborrhea Flashcards
1
Q
Layers of keratinization
A
- keratinized squames
- granule cell layer
- prickle cell lalyers
- basal cell laer
- basal lamina
2
Q
Cornification
A
- formation of cornified envelope
- synthesis of keratohyalin
- formation of lamellar bodies
- keratinization
*takes about 21-22 days
3
Q
Hormonal regulation of sebum production
A
- increased by androgens, thyroid and progesterone
- decreased by corticosteroids, estrogens, suppressing adrogens
4
Q
Sebum productions and dietary influence
A
- fat deficiency
- initial dec then inc in sebum production
- most dogs need a combo of saturated and unsaturated fats
- low levels of vitamin A
- dec sebum production….?
5
Q
Sebum composition
A
- sterol
- diester waxes
- free cholesterol
- triglycerides
- fatty acids
6
Q
Seborrhea sicca
A
- excessive scale formation (dry skin)
7
Q
Seborrhea oleosa
A
- Excessive secretion of grease on skin and hairs
8
Q
seborrheic dermatitis
A
- excessive presence of scales or grease with inflammation
9
Q
Primary seborrhea
A
- american cocker
- english springer spaniel
- inherited dz
- CS may be from birth
10
Q
Secondary seborrhea
A
- Internal or external stimuli (Inflammation)
- altered epidermal proliferation, differentiation and desquamation (cornification)
11
Q
pathogenesis of seborrhea
A
- inflammation
- histamine
- cytokins
- LTB4 and PGE2
- Endocrinopathies
- hormones
- Nutrition
- glucose proteins
- fatty acids
- vitamins, mineral
- Environment
- bathing
- lipids/water
12
Q
Clinical signs
A
- Seborrhea sicca
- Seborrhea oleosa
- Seborrheic dermatitis
- Ceruminous otitis
- Secondary infestations
13
Q
Primary causes Seborrhea
A
- idiopathic
- zinc responsive dermatitis type 1
- schnauzer comedo syndrome
- Epidermal dysplasia
- Vitamin A responsive seborrhea
14
Q
Secondary seborrhea
A
malassezia dermatitis
15
Q
TX primary idiopathic seborrhea
Topical
Systemic
A
- Topical
- keratolytic/keratoplastic shamppos
- antimicrobial shampoos
- Systemic
- oral retinoids
- fatty acids
- antimicrobials
16
Q
Zn responsive dermatosis
Primary
A
- breeds
- alaskan malamute, husky, samoyeds
- pathogenesis
- inherited inpairment to metabolize zn
- CS
- age 1-3 years old
- erythema, alopecia, crust, scales, hyperkeratotic foot pads
- mucocutaneous junctions of face
- malassezia and back infections common
17
Q
Zn responsive dermatosis
Type II (Secondary)
A
- Breeds
- rapidly growing large breeds
- Pathogenesis
- nutrition
- CS
- thick, well demarcated plaques and crusts
- periocular and perioral areas and genitalia
- malassezia and bacterial infections common
18
Q
Zn responsive dermatosis
TX
Topical
Systemic
A
- Topical
- kertolytic/keratoplastic shampoos
- antimicrobial shampoos
- Systemic
- Zn supplement
- antibiotics, antifungals
19
Q
Schnauzer comedo syndrome
A
- Breed
- schnauzer
- pathogenesis
- unknown
- CS
- multiple comedones on dorsal midline
- alopecia, erythema, crusted papules, follicular cysts
- secondary infections
20
Q
Schnauzer comedo syndrome
TX
Topical
Systemic
A
- topical
- karotolytic/keratoplastic shampoos
- antimicrobial shampoos
- systemic
- oral retinoids (helps with kertinization)
- antimicrobials
21
Q
Malassezia spp
A
- broad based
- M. pachidermatis
- Commensal of skin and ears
- inc numbers in humid and warm conditions
- secondary to other dz
- malassezia hypersnesitivity
22
Q
Malassezia spp has a commensal relationship with….
A
Staphylococci
23
Q
Malassezia spp
Predisposing factors
A
- humidity
- breed
- barrier changes
- malassezia (unlike Candida) not subject to inhibitory effects of bacteria
24
Q
Yeast numbers do not always relate to….
A
severity of clinical signs
25
malassezia Clinical presentation
* Pruritus/erythema
* scaling/seborrhea
* paronychia
* lichenification/hyperpigmentation
* ventral body
* neck, axillae, abdomen
* face/ear pinnae
* feet/forelegs
* skin folds
* otitis externa/media
26
malassezia dx
* swabs
* tape
* impression smear
\*fix sample to remove some fat....
27
Topical tx
seborrhea sicca
* moisturizing
* emollient vs. humectant
* hypoallergenic
* oatmeal and lanolin
* sulfur +/- salicylic acid
* antimicrobial
28
Topical tx
Seborrhea oleosa
* selenium sulfate
* sulfur +/- salicylic acid
* Tar
* Benzoyl peroxide
* Antimicrobial
29
Keratoplastic
* dec DNA =\> dec mitosis =\> dec cell ontogenesis
30
Keratolytic
* dec cohesion between corneocytes =\> inc desquamation
31
Emollient
* Moisturize skin =\> dec TEWL (trans epidermal water loss)
32
Humectant
* moisturize the skin =\> dec TEWL and recall water from dermis and environment
* more powerful than an emollient
33
Benzoyl peroxide
* Keratolytic: benzoic acid
* Antibacterial
* **no antifungal**
* degreasing
* aggressive =\> irritant
* bleaching agent
34
Selenium sulfate
| (selsun blue)
* Keratolytic: dec hydrogen bonds between keratines
* Keratoplastic: dec cellular turn-over
* Degreasing
* Antifungal: Malassezia
35
Sulfur
* Keratolytic: hydrogen sulfate
* Keratoplastic: interaction with cysteine in keratinocytes
* Degreasing
* Antimicrobial and antiparasitic
* pentatonic acid and hydrogen sulfate
* antibacterial and **antifungal**
## Footnote
**\*DOES EVERYTHING!!!!**
**\*STINKS**
36
Salicylic
also selsun blue....?
* Shampoo 0.1-2%
* Keratoplastic
* Antipruritic
* Bacteriostatic
* Shampoo 3-6%
* keratolytic
37
Sulfur + salicylic acid
Synergistic action
38
Tar
* shampoo
* keratolytic
* keratoplastic
* degreasing
* side effects
* malodourous
* Irritant and pohtosensitizing
* carcinogenic
39
Emollients
* Mainly oils
* vegetable oils
* animal oils
* silicon, waxes and hydrocarbons
* apply after shampoo
40
Humectants
* Hygroscopic agents
* propylene glycol
* Glycerin
* Colloidal oatmeal
* Urea
* Sodium lactate
* Lactic acid
\*Colloidal oatmea
41
Phytosphingosine
* Shampoos, lotions, etc
* Pro-ceramide: naturally present in skin
* Anti-inflammatory
* Antimicrobic
42
Miscellaneous
* Zinc gluconate
* anti-seborrheic
* inhibitor of 5alpha-reductase
* dec sebum production
* Vitamin B6
* dec syndergistically with Zn
* Essential fatty acids
* dec TEWL
43
Novasomes and spherulites
* nano particles
* adheres to skin and hairs
* slow release of activ ingredient
44
Antimicrobial shampoo
summary
* Sulfur
* bacteria
* yeast
* Chlorahexidine
* bacteria only
* Benzoyl peroxide
* bacteria only
* Miconazole
* bacteria
* yeast
* Selenium sulfate
* yeast only
45
Systemic treatment
* Ketoconazole
* Itraconazole
* Fluconazole
* Terbinafine
