Lecture: Keratinization disorders/seborrhea Flashcards Preview

Dermatology > Lecture: Keratinization disorders/seborrhea > Flashcards

Flashcards in Lecture: Keratinization disorders/seborrhea Deck (45)
Loading flashcards...
1
Q

Layers of keratinization

A
  1. keratinized squames
  2. granule cell layer
  3. prickle cell lalyers
  4. basal cell laer
  5. basal lamina
2
Q

Cornification

A
  1. formation of cornified envelope
  2. synthesis of keratohyalin
  3. formation of lamellar bodies
  4. 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
Q

malassezia Clinical presentation

A
  • Pruritus/erythema
  • scaling/seborrhea
  • paronychia
  • lichenification/hyperpigmentation
  • ventral body
    • neck, axillae, abdomen
  • face/ear pinnae
  • feet/forelegs
  • skin folds
  • otitis externa/media
26
Q

malassezia dx

A
  • swabs
  • tape
  • impression smear

*fix sample to remove some fat….

27
Q

Topical tx

seborrhea sicca

A
  • moisturizing
    • emollient vs. humectant
  • hypoallergenic
  • oatmeal and lanolin
  • sulfur +/- salicylic acid
  • antimicrobial
28
Q

Topical tx

Seborrhea oleosa

A
  • selenium sulfate
  • sulfur +/- salicylic acid
  • Tar
  • Benzoyl peroxide
  • Antimicrobial
29
Q

Keratoplastic

A
  • dec DNA => dec mitosis => dec cell ontogenesis
30
Q

Keratolytic

A
  • dec cohesion between corneocytes => inc desquamation
31
Q

Emollient

A
  • Moisturize skin => dec TEWL (trans epidermal water loss)
32
Q

Humectant

A
  • moisturize the skin => dec TEWL and recall water from dermis and environment
  • more powerful than an emollient
33
Q

Benzoyl peroxide

A
  • Keratolytic: benzoic acid
  • Antibacterial
  • no antifungal
  • degreasing
  • aggressive => irritant
  • bleaching agent
34
Q

Selenium sulfate

(selsun blue)

A
  • Keratolytic: dec hydrogen bonds between keratines
  • Keratoplastic: dec cellular turn-over
  • Degreasing
  • Antifungal: Malassezia
35
Q

Sulfur

A
  • Keratolytic: hydrogen sulfate
  • Keratoplastic: interaction with cysteine in keratinocytes
  • Degreasing
  • Antimicrobial and antiparasitic
    • pentatonic acid and hydrogen sulfate
    • antibacterial and antifungal

​​*DOES EVERYTHING!!!!

*STINKS

36
Q

Salicylic

also selsun blue….?

A
  • Shampoo 0.1-2%
    • Keratoplastic
    • Antipruritic
    • Bacteriostatic
  • Shampoo 3-6%
    • keratolytic
37
Q

Sulfur + salicylic acid

A

Synergistic action

38
Q

Tar

A
  • shampoo
  • keratolytic
  • keratoplastic
  • degreasing
  • side effects
    • malodourous
    • Irritant and pohtosensitizing
    • carcinogenic
39
Q

Emollients

A
  • Mainly oils
    • vegetable oils
    • animal oils
    • silicon, waxes and hydrocarbons
  • apply after shampoo
40
Q

Humectants

A
  • Hygroscopic agents
    • propylene glycol
    • Glycerin
    • Colloidal oatmeal
    • Urea
    • Sodium lactate
    • Lactic acid

*Colloidal oatmea

41
Q

Phytosphingosine

A
  • Shampoos, lotions, etc
  • Pro-ceramide: naturally present in skin
  • Anti-inflammatory
  • Antimicrobic
42
Q

Miscellaneous

A
  • Zinc gluconate
    • anti-seborrheic
    • inhibitor of 5alpha-reductase
      • dec sebum production
  • Vitamin B6
    • dec syndergistically with Zn
  • Essential fatty acids
    • dec TEWL
43
Q

Novasomes and spherulites

A
  • nano particles
  • adheres to skin and hairs
  • slow release of activ ingredient
44
Q

Antimicrobial shampoo

summary

A
  • Sulfur
    • bacteria
    • yeast
  • Chlorahexidine
    • bacteria only
  • Benzoyl peroxide
    • bacteria only
  • Miconazole
    • bacteria
    • yeast
  • Selenium sulfate
    • yeast only
45
Q

Systemic treatment

A
  • Ketoconazole
  • Itraconazole
  • Fluconazole
  • Terbinafine