Clinical Therapeutics - Dermatology

Question 1

How do you treat fold dermatitis?

Answer 1

• Topical antiseptics/ anti-microbial and topical/systemic anti-inflammatories
• Look for underlying cause e.g., obese dogs causing a deep vulvar fold = weight loss

Question 2

How do you treat superficial pyoderma?

Answer 2

• 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
  – Empirical choice, if first time infection and no AMR risk

Question 3

How do you treat ‘Hot Spot’?

Answer 3

• Clip (often need sedation) and clean
• topical antiseptic/antimicrobial
• Systemic/topical anti-inflammatory e.g., steroids and pain relief e.g., paracetamol
• Look for underlying cause e.g., allergy (FAD) or pruritic/painful trigger; predisposed breed?

Question 4

How do you treat malassezia dermatitis?

Answer 4

• Shampoo first line treatment =
  – chlorhexidine 2% + miconazole 2%
  – chlorhexidine >= 3%
• Other topical preparations for skin and ears
  – clotrimazole, miconazole, nystatin, terbinafine, selenium sulfide
• Systemic antifungals
  – only if chronic or severe and underlying disease addressed
• Allergy vaccine
  – if patient has atopic dermatitis and is hypersensitive

Question 5

What are different antiseptics for skin?

Answer 5

• Chlorhexidine =
• Shampoo 0.8 - 4%
• Conditioner 3%
• Sprays 3-4%
• Gels 0.3-0.5%
• Wet Wipes 0.3-4%
• Hypochlorous acid = Spray/ rinse <0.005%

Question 6

How do you treat deep pyoderma?

Answer 6

• What is the underlying cause?
• Localised – Topical antiseptics and antibiotics
• Severe/ widespread, especially if patient systemically unwell
  – Systemic antibiotics always based on C+S
  – Biopsy fresh tissue >swab from furuncle >swab from sinus tract (CSLI laboratory interpretative breakpoints should be used)

Question 7

What duration of antibiotics are needed for different pyodermas?

Answer 7

• Superficial = 2-3weeks
• Deep = 4+ weeks

Question 8

How would you treat immune mediated skin diseases?

Answer 8

• Removal or treatment of any external triggers =
• Drugs, UV light, confirmed infections, underlying neoplasia
• Control of inappropriate immune response =
• Immunosuppressive/immunomodulatory drugs - prednisolone
• Topical therapy for mild or localised disease
• Combination drug therapy for severe or relapsing disease (generally more effective and better tolerated)

Question 9

What are different phases of treatment?

Answer 9

• Induction of remission - days-weeks, aggressive tx (avoid AE, regular monitoring)
• Transition - weeks-months, lowest effective dose, monitoring reduces with absence of AE (if no relapse = stop tx to determine cures)
• Maintenance - months-years, if relapses, lowest effective dose + monitor

Question 10

How would you monitor patients + adjust therapy?

Answer 10

• Complete blood count
• Biochemistry
• Urinalysis
• induction every 7-14d
• transition every 2-6 wks
• maintenance every 1-6months

Question 11

What IMSD can you treat with just steroids?

Answer 11

• 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
• SLO
• Cutaneous Lupus Erythematosus

Question 12

What are different ways steroids are used?

Answer 12

• Physiological dosing (low dose) = Replace glucocorticoids that are absent in hypoadrenocorticism (adrenal insufficiency)
• Anti-inflammatory dosing (intermediate dose) = Reduce inflammation and pruritus through a variety of mechanisms
• Immunosuppressive dosing (high dose) = Severely compromise immune responses to control immune-medicated disease

Question 13

What are precautions when using steroids?

Answer 13

• Potent affect on pregnancy = CARE
• Do not mix with NSAIDs = stomach irritation + ulceration
• ADVERSE EFFECTS =
• Polydipsia / polyphagia / polyuria
• Muscle weakness
• Breathlessness or panting
• Weight gain and/or abdominal enlargement
• Alopecia, secondary bacterial infections and calcinosis cutis

Question 14

What are adverse effects of ciclosporin?

Answer 14

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

Question 15

What are properties of topical treatments?

Answer 15

• Cleansing
• Keratoplastic (reduce cell turnover in skin = reduce scale production) - antiseborrhoeic (e.g. sulphur + tar)
• Keratolytic (remove cells from surface of skin) - antiseborrhoeic (e.g. salicylic acid)
• Emollient - moisturise + restore barrier function - lanolin
• Antimicrobial
• Anti-inflammatory

Question 16

What is treatment of sebaceous adenitis?

Answer 16

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

Question 17

• What basic test is used to diagnosis pyoderma in the clinic?
• What is first-line treatment of superficial pyoderma?
• What is the best sample to send for culture, in cases of deep pyoderma?
• Which bacteria are usually the cause of superficial and deep pyoderma?
• What antibiotic class are all MRSP resistant to?
• What are possible underlying triggers of IMSD?
• What is the most common drug used to treat IMSD?
• How often should you re-examine a patient with IMSD during induction or remission phase?
• What monitoring tests should you perform in patients with IMSD?