Clinical Therapeutics

Question 1

Name two common surface overgrowth skin problems

Answer 1

Pyotraumatic dermatitis (“hot spots”)
Fold dermatitis

Question 2

How can you treat ‘hot spots’

Answer 2

Look for underlying cause e.g., allergy (FAD) or pruritic/painful trigger; predisposed breed?
- Happen overnight
- Will see an overgrowth of cocci
- Clip and clean with topical antiseptic/antimicrobial
- Systemic anti-inflammatory and pain relief

Question 3

How would you treat fold dermatitis?

Answer 3

• Topical antiseptics/ anti-microbial and topical/systemic anti-inflammatories
• Look for underlying cause e.g., obese dogs causing a deep vulvar fold -> weight loss
• May progress to superficial or deep infection
• Can occur around the tail base, vulva, lips, etc

Question 4

Which lesions are seen in superficial pyoderma

Answer 4

Pustules, papules, macules, crusts, erythema, staphylococcus, plaques, epidermal collarette

Question 5

What is staphylococcal folliculitis?

Answer 5

Pustule of the hair follicle

Question 6

How is superficial pyoderma treated?

Answer 6

Underlying cause – identify, treat/ manage
Topical treatment is most important
Systemic antibiotics ONLY if severe/ widespread proven infection and/or no response to above - Preferably chosen by swab culture

Question 7

Topical therapy is the sole therpay for which conditions?

Answer 7

Surface infections, otitis externa and many cases of superficial pyoderma

Question 8

Why is topical therpay used adjunct to systemic therpay?

Answer 8

improve efficacy and speed cure

Question 9

How does Malassezia present?

Answer 9

Cobblestone appearance of the ventral neck – skin thickening
Extremely pruritic

Question 10

What is the first line treatment for Malassezia dermatitis?

Answer 10

Shampoo first line treatment
- Chlorhexidine 2% + miconazole 2%
- Chlorhexidine >= 3%

Question 11

What are the other treatment options for Malassezia dermatitis?

Answer 11

1. Other topical preparations for skin and ears - Clotrimazole, miconazole, nystatin, terbinafine, selenium sulfide
2. Systemic antifungals - Only if chronic or severe and underlying disease addressed
3. Allergy vaccine
   - If patient has atopic dermatitis and is hypersensitive
   - Desensitise the patient against the yeast

Question 12

Which factors help to select treatment for deep skin infections?

Answer 12

• Patient may be more painful that pruritic
• Can be systemically unwell
• Can have deep and superficial skin infections simultaneously but need to be treated differently as different parts of the skin are damaged
• What is the underlying cause?
• Localised: Topical antiseptics and antibiotics
• Severe/ widespread, especially if patient systemically unwell: systemic antibiotics always based on culture and susceptibility

Question 13

When is antimicrobial use is indicated, how they are used appropriately?

Answer 13

• Choice based on cytology +/- culture and susceptibility testing
• Use correct drug, dose, frequency and duration
• Give good (written) instructions to owners
• Drug choice: Pharmacokinetics, pharmacodynamics, susceptibility of the organism, antimicrobial prescribing guidelines and drug cascade

Question 14

How long are antibiotics needed for superficial pyoderma?

Answer 14

2-3 weeks

Question 15

How long are antibiotics needed for deep pyoderma?

Answer 15

4+ weeks
For deep infections there may be an initial rapid response, but then improvement occurs quite slowly; if progress stops repeat culture

Question 16

Describe the features of 1st line antibiotics

Answer 16

• Not restricted
• High index of suspicion of, or proven infection
• Based on likely microbe and C+S

Question 17

Name some 1st line antibiotics

Answer 17

Amoxicillin +/- clavulanate
Tetracycline/doxycycline
Clindamycin
Cephalexin
Metronidazole

Question 18

Describe the features of 2nd line antibiotics

Answer 18

• Semi-restricted, case by case
• Only if no 1st line drug
• Infection evident and C+S uploaded
• Consent from senior clinician

Question 19

Name some 2nd line antibiotics

Answer 19

Minocycline
Cefovecin
Enrofloxacin/marbofloxacin
Gentamycin

Question 20

Describe the features of 3rd line antibiotics

Answer 20

• Restricted, case by case
• Only if no 1st or 2nd line drug
• Infection evident (C+S)
• Consent from senior clinician
• Prescription completed

Question 21

Describe the features of 4th line antibiotics

Answer 21

• Only option and good chance of successful outcome
• Consent from infection control lead
• Infection evident
• Prescription completed

Question 22

How would you treat a staphylococcus pseudointermedius infection?

Answer 22

• Intense topical antiseptics
• Prednisolone
• Contact owner with culture results and only use antibiotics if needed e.g. cephalexin
• Re-examine in 2 weeks

Question 23

What are the principles of treatment for immune-mediated skin disease?

Answer 23

1. Removal or treatment of any external triggers - Drugs, UV light, confirmed infections, underlying neoplasia
2. Control of inappropriate immune response
   - Immunosuppressive/immunomodulatory drugs
   - Topical therapy for mild or localised disease

Question 24

Name the 3 phases of treatment for immune mediated skin disease

Answer 24

• Induction of remission
• Transition
• Maintenance

Question 25

Describe the induction of remission phase of treatment for immune mediated skin disease

Answer 25

- Need to do biochem and haematology first to find out basal parameters - Days to weeks - Aggressive therapy: immunosuppressive doses of steroids - May need to change/add treatments if minimal response after 2-4 weeks - Try to avoid severe adverse effects - Regular treatment monitoring

Question 26

Describe the transmission phase of treatment for immune mediated skin disease

Answer 26

- Weeks to months - Taper to lowest effective dose - Taper drugs with most risk of adverse effects first - Treatment monitoring frequency reduces with time and absence of adverse effects - Bloods - If no relapse with advanced dose tapering stop treatment to determine cures

Question 27

Describe the maintenance phase of treatment for immune mediated skin disease

Answer 27

- Months to years - Cases where relapses have occurred in transition phase - Lowest effective dose and monitor for adverse effects - Treatment monitoring as determined by treatment and dose - Further tapering if disease in remission for many months - For idiopathic cases that are lifelong and wont cure

Question 28

How can you monitor patient during treatment and adjust therapy when needed?

Answer 28

- Baseline drug monitoring obtained prior to starting therapy - Induction every 7-14 days - Transition every 2-6 weeks - Maintenance every 1-6 months (case dependant)

Question 29

What is the primary treatment for immune mediated skin disease?

Answer 29

Steroids E.g. Prednisolone 1-2mg/kg/day until stable (1-2 weeks), and then gradually taper every 1-2 weeks until reach minimal effective dose and frequency

Question 30

If a steroid alone is producing a sub-optimal response which treatment might you add to the therpay?

Answer 30

Cytotoxic drug May also need cytotoxic drug to achieve lowest effective steroid dose/frequency to reduce potential drug side effects

Question 31

List some examples of immune mediated skin diseases that are treated with steroids

Answer 31

- Eosinophilic furunculosis of the face - Juvenile sterile granulomatous dermatitis and lymphadenitis - Vasculitis or vasculopathy (may respond to oclacitinib) - Sterile pyogranulomatous dermatitis and panniculitis - Pemphigus foliaceus (PF) - Uveodermatological syndrome - Erythema multiforme - Sebaceous adenitis - Anal furunculosis

Question 32

Describe physiological dosing of steroids

Answer 32

Low dose - Replace glucocorticoids that are absent in hypoadrenocorticism (adrenal insufficiency)

Question 33

Describe anti-inflammatory dosing of steroids

Answer 33

Intermediate dose Reduce inflammation and pruritus through a variety of mechanisms

Question 34

Describe immunosuppressive dosing of steroids

Answer 34

High dose Severely compromise immune responses to control immune-medicated disease

Question 35

List some common side effects of steroids

Answer 35

- Polydipsia, polyphagia, polyuria - Muscle weakness - Breathlessness or panting - Weight gain and/or abdominal enlargement - Alopecia, secondary bacterial infections, calcinosis cutis

Question 36

How long does ciclosporin efficacy take?

Answer 36

2-8 weeks

Question 37

Ciclosporin is the main therapy of a number of IMSD - list some examples

Answer 37

- Anal furunculosis (AF) - Symmetrical lupoid onychodystrophy (SLO) - Cutaneous lupus erythematosus (CLE) - Erythema multiforme (EM) - Sebaceous adenitis (SA) - Cutaneous histiocytosis - Adjunct in Pemphigus foliaceus (PF)?

Question 38

What are the side effects of Ciclosporin?

Answer 38

Vomiting and diarrhoea Increased hair and gum growth due to increased TGFb Immunosuppression Papilloma growth

Question 39

List some properties of topical agents used in skin disease

Answer 39

Cleansing Keratoplastic - Antiseborrhoeic Keratolytic - Antiseborrhoeic Emollient Antimicrobial Anti-inflammatory

Question 40

Define keratoplastic

Answer 40

Reduce cell turnover in the skin to reduce scale production

Question 41

Define keratolytic

Answer 41

Shampoo removes the cells from the surface of the skin e.g. salicylic acid

Question 42

Describe urea as a component of moisturisers

Answer 42

Binds water - promotes hydration, antibacterial, keratolytic

Question 43

Describe glycerine as a component of moisturisers

Answer 43

Hygroscopic - absorbed into skin

Question 44

Describe propylene glycol as a component of moisturisers

Answer 44

Potent softening and hydroscopic agent

Question 45

How would you treat sebaceous adenitis?

Answer 45

1. Ciclosporin to save residual sebaceous glands 2. Prednisolone until ciclosporin takes effect and to reduce pruritus 3. Commonly have secondary infections - Topical antiseptics 4. Sebaceous glands destroyed so loss of oils to the skin and coat - Remove thick scales - Rehydrate