Dermatology Flashcards
The skin makes up ?% of the total body weight of a newborn puppy?
24%
The skin makes up ?% of the body weight in an adult animal?
12%
What are the 3 layers of the skin?
- epidermis
- dermis
- hypodermis
What are the differences between Human and Animal Skin?
- humans have more sweat glands
- human skin is thicker
- animals have multiple hairs on 1 follicle
What is the Epidermis?
most superficial layer that contains cells, but not blood vessels
What is the Dermis?
- middle layer
- composed of: blood and lymph vessels, nerve fibers and the accessory organs of skin such as glands and hair follicles
What is the Hypodermis?
- subcutaneous
- deepest layer that is composed of connective tissue (fat)
What does the Skin protect the animal from?
- environment
- physical, chemical and mircobial injury
What do the sensory organs in the Skin allow the animal to do?
feel pain, heat, cold, touch and pressure
What is the Skin the “storage depot” for?
- electrolytes
- water
- protein
- fats
- carbohydrates
What does the Hypodermis store?
- fat for insulation
- energy reserves
What are the functions of the Skin?
- enclosing barrier
- environmental protection
- temperature regulation
- sensory perception
- motion and body shape
- antimicrobial
- blood pressure control
- secretion
- adnexa
- storage
- pigmentation
- excretion
- Vitamin D production
Enclosing Barrier
protects the internal environment of the body from water and electrolyte loss
Environmental Protection
protects the internal environment from the external environment
Temperature Regulation
maintains the animal’s coat and regulates the blood supply to the cutaneous tissues, which regulate heat dissipation and retention
Sensory Perception
contains sense organs for touch, temperature and pain
Motion and Shape
allows for motion and provides a definition to the body
Antimicrobial
contains antimicrobial and antifungal properties
Blood Pressure Control
the peripheral vascular beds within the skin help to control blood pressure
Secretion
contains both apocrin and sebaceous glands
Adnexa
produces hair, nails, hooves and horny layers of the epidermis
Storage
stores electrolytes, water vitamins,fats, proteins, carbs and other substances
Pigmentation
process within the skin (melanin formation) helping to determine coat and skin color and provide solar protection
Excretion
the animal’s skin has a limited excretory function
Vitamin D Production
the skin is essential for solar energy activation, which is necessary for normal calcium absorption
What is Dermatology?
study of disease of the skin
What is Dermatosis?
skin disease
What is Alopecia?
hair loss
What is Seborrhea?
excessive secretion of sebum (oily secretion of the sebaceous glands composed of fat and epithelial debris)
What is Scale?
flakes of stratum corneum on the skin surface or hair coat
comes in various colors
What is Erythema?
increased redness
What is Collarette?
circular arrangement of scale with central area of hyperpigmentation
What is Crust?
accumulation of dead cells and exudate on skin surface
What are Ectoparasites?
external parasites
What is Skin Scraping?
method of examining skin for parasites
What is Dermatophyte?
fungi that grow on the skin
What is Dermatomycosis (ringworm)?
a skin infection with keratinophilic fungi (Microsporum, Trichophyton, Epidermophyton)
What is Pyoderma?
bacterial infection of skin (superficial, deep)
When is a Fungal Culture?
lab test used to grow dermatophytes for identification
used for ringworms
What is Bacterial Culture and Sensitivity?
lab test used to grow and identify bacteria from lesions and determine antibiotic sensitivity
What is Impetigo?
superficial bacteria skin infection seen in young dogs “puppy pyoderma” (staph)
What is Acne?
pores clogged with oil forming “blackheads”, especially chin
What is a Lesion?
area of altered skin
What is a Rash?
wide spread eruption of lesions
What is Hyperpigmentation?
increased pigmentation (melanin) of skin (epidermis/dermis)
What is Lichenification?
thickening and hardening of skin characterized by exaggerated superficial skin markings
What is a Cyst?
fluctant nodule, walled off, fluid filled
What is a Macule?
a focal, circuscribed, nonpalpable change in color <1 cm (when its larger, termed a patch)
What is a Papule?
small, circumscribed, solid elevated lesion of the skin
1 cm
What is a Wheal?
a sharply circumscribed, raised, edematous lesion that appears and disappears within minutes to hours
What is a Pustule?
a small, elevated, circumscribed, pus containing lesion of the skin within the epidermis
What is an Abscess?
localized collection of pus
larger than a pustule
What is Cellulitis?
swollen, tender area of skin with bacterial infection
can develop into an abscess
What is Granulation Tissue?
new tissue in a healing wound
consists of connective tissue and capillaries
What is an Erosion?
loss of skin surface
shallow, moist, crusted
doesn’t penetrate basement membrane
What is an Ulcer?
loss of epidermis resulting in exposure of dermis
What is a Comedone?
dilated hair follicle blocked with sebum and other cellular debris
What is Seborrhea?
abnormal flaking or scaling of the epidermis and may be accompanied by increased oil production (seborrhea oleasa) or not (seborrhea sicca)
What is the normal skin cell turnover time?
~3weeks
What is the Primary cause of Seborrhea?
hereditary as in American Cocker Spaniel, English Springer Spaniel, Westies, Basset Hounds
What are the Secondary causes of Seborrhea?
disease/injury to skin from other causes
allergies, parasites, nutritonal disorders, immune mediated, endocrine disorders (hypothyroidism)
What are the 2 types of Seborrhea?
- seborrhea sicca: dry, only scaliness
- seborrhea oleosa: oily + scales
What do Keratolytics do?
- remove excess keratin and promote loosening of the outer layers of the epiderms
- break down protein structure of kerating layer, permitting easier removal of material
Where are Keratolytics found?
medicated shampoos
What Medicated Shampoos are used for Seborrhea Sicca?
- sulfur (keratolytic, antipuritic, antibacterial, antifungal, antiparasitic)
- salicyclic acid (KL, AP, AB)
What Medicated Shampoos are used for Seborrhea Oleaso?
- coal tar (degreaser, keratolytic)
- benzoyl peroxide (also for moist dermatitis, pyoderma, stud tail)
What is the treatment for Seborrhea?
- clip hair so shampoo can penetrate
- if secondary, treat underlying cause (antifungal and/or antibacterial meds)
- Omega 3 fatty acid supplements (anti inflammatory, antipuritic properties)
What are the causes of Seborrheic Fungal Dermatitis?
- Malassezia species
- some commensal on skin (normal)
How do you diagnose Seborrhic Fungal Dermatits?
cytology
skin impressions
How do you treat Seborrheic Fungal Dermatits?
- 2% miconazole/ 2% chlorhexidine shampoo
- selenium sulphide
- other antifungals(ketoconazole, clotrimazole, miconazole)
- oral ketoconazole X 3+ weeks (not for dogs and cats)
What are Pyodermas?
bacterial infections that involve the skin
may be primary or secondary, superficial or deep
Pyodermas occur when:
- skin surface broken
- skin maccerated by chronic exposure to moisture
- normal bacteria altered
- circulation impaired
- immunosuppression
What are Superficial Pyodermas?
- involve only superficial epidermis
- healing occuring without scarring
- short duration
- rarely systemically ill
- skin around lesions remain normal
- affected portions may be ulcerated or traumatized by animal
What is the cause of Pyodermas in dogs?
staph intermedius
What is the cause of Pyodermas in cats?
pasteurella multocida
What are the causes of Deep Pyodermas?
gram negative organisms (e. coli, proteus sp., pseudomonas sp.)
Wh:at are the risk factors of Pyodermas?
- allergies
- fungal infections
- endocrine diseases
- immune incompetence
- seborrhea
- conformation ex: skin folds
- trauma
- foreign bodies
Where do Superficial Pyodermas commonly affect?
trunk