Feline cutaneous reaction patterns

Question 1

What are the 4 feline cutaneous reaction patterns?

Answer 1

1. Self-induced alopecia (SIA)
2. Face, head and neck pruritus (FHN)
3. Miliary dermatitis (MD)
4. Eosinophilic granuloma complex (EGC)

Question 2

SIA

Answer 2

• Bilaterally symmetrical alopecia in areas that cat can reach with tongue
• Hair often stubbly
• Damaged distal tips on trichograms
• Often not recognised by owner
• +/- tufts of hair in house, vomiting furballs, hair in faces
• Ddx spontaneous loss: may also be symmetrical
  – Much less common
  – Hair often easily epilated

Question 3

FHN pruritus

Answer 3

• ~36% cases (out of 502 pruritic cats) due to ectoparasites, especially fleas

Question 4

MD

Answer 4

• Papulocrustous lesions, especially on dorsum
• Usually only feel, don’t see due to hair

Question 5

3 types of EGC

Answer 5

• eosinophilic granuloma
• eosinophilic plaque
• indolent ulcer

Question 6

Eosinophilic granuloma

Answer 6

• Well-demarcated, solid, raised, yellow to pink plaques/nodules
• +/- eroded or ulcerated surface
• +/- crust
• Any site but especially caudal thighs (linear), oral cavity
• ‘fat chin’

Question 7

Eosinophilic plaque

Answer 7

• Raised, flat-topped erythematous plaques
• Usually ulcerated/eroded and pruritic
• Usually ventral abdomen/caudal thigh
• Secondary bacterial infection common

Question 8

Indolent ulcer

Answer 8

• ‘Rodent ulcer’
• Erosive/ulcerated lesion on mucocutaneous junction of upper lips
• Unilateral/bilateral
• Rarely painful or pruritic

Question 9

SIA ddx

Answer 9

• FAD**
• FFA**
• FASS**
• D gatoi*
• Dermatophytosis*
• Malassezia dermatitis
• Feline paraneoplastic alopecia
• Psychogenic alopecia
• FLUTD/pain/neuralgia

Question 10

MD ddx

Answer 10

• FAD**
• FFA**
• FASS**
• Dermatophytosis*
• Pyoderma*
• Cheyletiella*
• Neotrombicula*
• Otodectes*
• Pemphigus foliaceus

Question 11

EGC ddx

Answer 11

• FAD**
• FFA**
• FASS**
• Cowpox*
• Mycobacterial infections*
• Neoplasia (cut lymphoma, MCT, SCC)*
• Deep bacterial infections
• Fungal disease
• Respiratory viruses
• Insect bite HS

Question 12

FHN ddx

Answer 12

• FAD**
• FFA**
• FASS**
• D cati*
• Otodectes*
• Insect bite HS*
• Dermatophytosis*
• Malassezia dermatitis
• Respiratory viruses
• Bacterial pyoderma
• Pemphigus foliaceus
• Skin neoplasia (MCT, SCC, cut lymphoma)
• Drug reactions (methimazole)
• Idiopathic facial dermatitis (Persians)
• FOPS (esp Burmese)

Question 13

What does FAD stand for?

Answer 13

• Flea allergic dermatitis

Question 14

What does FFA stand for?

Answer 14

• Feline food allergy

Question 15

What does FASS stand for?

Answer 15

• Feline atopic skin syndrome

Question 16

If these reaction patterns co-exist what conditions does it likely indicate?

Answer 16

• allergic or flea based problem