Commonly used therapeutics in skin disease Flashcards
What are the aims of skin disease therapetics?
Kill/repel parasites - ectoparasiticides
Control/cure microbial infection - antimicrobials
Control inflammation/pruritus - Drugs for atopic dermatitis and autoimmune disease
Moisturise/improve skin barrier function
Resolve scale - antiseborrhoeic agents
treat otitis externa
What are the different types of therapeutics that aim to moisturise/improve skin barrier function?
emollients
Moisturisers
Agents to improve skin barrier function e.g., essential fatty acids, essential oils, ophytrium
Describe how emollients work
Soften, lubricate and soothe skin
Occlusive (seal water content in stratum corneum) => decreases trans-epidermal water loss
animal/plant oil based - e.g., lanolin, coconut oil, vaseline
Describe how moisturisers work, give examples
Increase water content of stratum corneum
e.g., colloidal oatmeal, aloe vera, urea, glycerine, propylene, glycol
Describe the actions of antiseborrhoeic agents
Keratolytic - reduce cohesion between cells of stratum corneum
Keratoplastic - restore normal epidermal epithelialisation and keratinisation, reduce epithelial turnover
+/- degreasing
Give examples of antiseborrhoeic agents
sulphur
salicylic acid
ammonium lactate
Why is it important to identify the underlying primary problem in otitis externa?
Ear infections are often secondary to allergies or other conditions
Treating underlying cause is necessary for long-term resolution
How does dysbiosis contribute to otitis externa?
Microbial imbalances precede infection
Early intervention with topical corticosteroids ± antimicrobial cleaners can prevent full infection, reducing need for antibiotics
Why is cytology essential in treating otitis externa?
Helps confirm infectious agent
Guides appropriate treatment selection, preventing unnecessary antibiotic use
What are the common ingredients in all ear drops/creams?
antibiotic
antifungal
corticosteroid
used to treat inflammation and secondary infection involved in otitis
What factors must be considered when choosing the correct treatment for otitis?
Organism present (cytology important)
Level of inflammatory activity required - use lowest potency glucocorticoid to be effective
Potential for ototoxicity if tympanic membrane ruptures
Nature of exudate - some antibiotics (e.g., polymixin-B) are inactivated by pus
Frequency of application - important for owner compliance
Give examples of glucocorticoids used in ear treatments from lowest to highest potency
What are the ingredients in ear cleaners and their functions?
Cerumenolytics - dissolve/soften cerumen e.g., squalene, propylene glycol
Antimicrobials e.g., chlorhexidine, acids
Surfactants - emulsify debris e.g., sodium decusate
Astringents - dry ear canal e.g., alcohols, acetic acid
When should you clean a patients ears?
To clean exudate from infected ears to facilitate access/efficacy of medicated drops
To contribute to management of microbial dysbiosis/overgrowth
For maintenance cleaning
What are the pros of topical therapy in dermatology?
Decreased concerns of side effects associated with systemic drugs e.g., antibiotics
Direct delivery of drug to site - high conc than systemic therapy
Targeted therapy on different areas of skin
What are the disadvantages of topical therapy in dermatology?
Labour intensive - issues with compliance
some animals do not tolerate
area of body may preclude e.g., shampoos around eyes
Hair may impede access to skin
Possible toxicity/loss of efficacy if licked off
