Pustular Diseases

Question 1

What is a pustule?

Answer 1

Small circumscribed fluid-filled elevation of the epidermis which contains pus

Question 2

Where can pustules be located?

Answer 2

Centred on hair follicles or may affect the inter-follicular epidermis

Question 3

What is the timeline of pustules?

Answer 3

Often transient with the predominant lesions in pustular diseases being crusts, epidermal collarettes or erosions

Question 4

What diseases are associated with pustules in dogs?

Answer 4

Most commonly pyoderma but drug eruptions, pemphigous foliaceus, subcorneal pustular dermatosis and sterile eosinophilic pustulosis also occur

Question 5

What diseases are associated with pustules in cats?

Answer 5

Pyoderma is rare so pemphigus foliaceus is the most common pustular disease

Question 6

What are the differential diagnoses of pustular diseases in dogs?

Answer 6

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Question 7

What is the approach to pustular disease in dogs?

Answer 7

Cytological examination of pustule contents and if consistent with pyoderma treat with antibiotics and re-examine after 10-20 days
If no response culture and sensitivity for bacteria and take skin biopsies for diagnosis of sterile pustular disease

Question 8

What is the approach to pustular disease in cats and horses?

Answer 8

Unusual in these species so wise to biopsy all cases but consider treating with antibiotics pending biopsy results