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A Practical Guide to Feline Dermatology

Table 23 : 1 : Aetiology of facial dermatoses

INFECTIOUS DERMATOSES

Poxvirus infection Herpesvirus infection

Herpesvirus-associated erythema multiforme

Papillomavirus infection

Bacterial folliculitis

Bite abscess

Acne

Leprosy

Atypical mycobacterial infection

Nocardiosis

Actinomycosis

Botryomycosis

FUNGAL DERMATOSES

Dermatophytosis

Malassezia dermatitis

Candidiasis

Subcutaneous mycoses

Sporotrichosis

Cryptococcosis

Histoplasmosis

Blastomycosis

Coccidioidomycosis

PARASITIC DERMATOSES

Notoedric mange

Otodectic mange

Demodicosis

Trombiculiasis

Cheyletiellosis

Leishmaniasis

ALLERGIC DERMATOSES

Atopic dermatitis Food intolerance Mosąuito bite hypersensitivity Allergic contact dermatitis

EOSINOPHILIC GRANULOMA COMPLEX

Indolent ulcer Eosinophilic granuloma

AUTO-IMMUNE DERMATOSES

Pemphigus foliaceus Pemphigus erythematosus

Pemphigus vulgaris Bullous pemphigoid Discoid lupus erythematosus, Systemie lupus erythematosus

OTHER IMMUNE MEDIATED DERMATOSES

Cutaneous drug reactions Auricular polychondritis Pseudopelade

HEREDITARY DERMATOSES

Hereditary epidermolysis bullosa Yitiligo

TRAUMATIC DERMATOSES

Burns Frostbite Actinic keratoses Irritant contact dermatitis

TUMOURS

Squamous celi carcinoma

Multicentric sąuamous celi carcinoma in situ (Bowen’s disease)

Basal celi tumour

Fibrosarcoma complex

Cutaneous epitheliotropic T celi lymphoma

“Mastocytic” mast celi tumour

“Histiocytic” mast celi tumour

DERMATOSES ASSOCIATED WITH A SYSTEMIC ILLNESS

Pancreatic paraneoplastic alopecia Paraneoplastic exfoliative dermatitis Degenerative mucinous lymphocytic mural folliculitis

SKIN CONDITIONS ASSOCIATED WITH BEHAYIOURAL DISORDERS

Preńous illness: an association between gastrointestinal problems and facial pruritus strongly suggests a food intolerance ⁸⁹. If the cat has gastrointestinal problems and is in poor generał health (e.g. with weight loss and dehydration), pancreatic paraneoplastic alopecia should be suspected ^l2. If there is a history of respiratory infection prior to ulcerative facial lesions, consider a viral dermatosis (e.g. herpesvirus infection) or herpesvirus-associated erythema multiforme.

Onset of clinical signs: the appearance of lesions some days after a change of environment (e.g. arrival of a new animal or change in living quarters) suggests a contagious condition such as a fungal infection (e.g. dermatophytosis), parasitic infestation or viral infection (e.g. poxvirus), or an allergic dermatitis (e.g. atopic dermatitis or food intolerance). If facial or generalised pruritus precedes the lesions, an allergic dermatitis, ectoparasitic infestation (e.g. trombiculiasis) or even a skin condition associated with a behavioural disorder (e.g. anxiety following a change in environment) should be suspected.

Progression of signs and seasonality: if signs worsen when the cat is in particular locations, atopic dermatitis should be suspected. Pruritic facial dermatoses that are morę prevalent in summer and

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