From Cat

Pruritus is a general term for itching or itchiness that results in a desire to scratch.

In cats, pruritus is commonly seen in association with food allergy dermatitis and fleas.

A comprehensive list of causes of pruritus in cats would include:

1. Ectoparasites - Notoedres spp, Cheyletiella spp, Otodectes spp, Demodex spp

usually in cats under 6 months of age, as is seen in canine mange

2. Allergies/Immune-mediated

- Flea-bite hypersensitivity - flea dirt evident in coat
- Mosquito-bite hypersensitivity - access to outdoors at dusk and dawn
- Adverse food reaction - young cats under 3 years old
- Atopy - generalised skin lesions as well as facial
- Contact dermatitis - usually oral/perioral lesions; also associated with application of ocular/oral/aural medications
- Eosinophilic granuloma complex

3. Bacteria & Fungi

- Cat bite abscess
- Feline acne
- Superficial pyoderma (Staphylococcus intermedius, Streptococcal spp, Pseudomonas aeruginosa, Proteus mirabilis, Actinomycosis), Persians predisposed to bacterial pyoderma and Malassezia infection due to facial conformation
- Dermatophytes (Microsporum spp, Trichophyton spp, Malassezia spp, Candida spp)
- Tuberculosis (mycobacterial infection), Feline Multisystemic Granulomatous Mycobacteriosis, Feline Leprosy

4. Viruses

- FHV Herpes virus
- Herpes virus-associated erythema multiforme in cats under 3 years of age; history of URTI
- Calicivirus infection
- Papillomavirus
- Feline Pox virus infection
- FeLV

5. Neoplasia

- Mast cell tumour
- Epitheliotropic lymphoma - Cutaneous lymphoma can be classified as epitheliotropic (closely conforming to the epidermis) or non-epitheliotropic. The epitheliotropic form is typically of T-cell origin and is also called mycosis fungoides. The non-epitheliotropic form is typically of B-cell origin. This is a rare disease in cats.
- Feline Sarcoid and/or Fibropapilloma
- Xanthoma
- Merkel Cell Tumour (neuroendocrine carcinoma)
- Melanoma
- Basal cell tumour
- Mast cell tumour
- Dilated Pore of Winer
- Squamous cell carcinoma, Solar Keratosis/Actinic Dermatitis, Multicentric Squamous Cell Carcinoma In Situ: Bowen's Disease
- Urticaria pigmentosa - primarily in Devon rex and Sphinx cats

6. Autoimmune

- Eosinophilic granuloma complex
- Pemphigus foliaceus
- Pemphigus erythematosus
- Discoid Lupus erythematosus
- Systemic Lupus erythematosus

7. Systemic disease

- Pancreatic paraneoplastic alopecia - usually a concurrent GI problem exists and poor condition (e.g. weight loss and dehydration).
- Paraneoplastic exfoliative dermatitis
- Degenerative mucinous lymphocytic mural folliculitis

8. Miscellaneous

- Idiopathic facial dermatitis
- Lymphocytic mural folliculitis
- Junctional epidermolysis bullosa
- Cutaneous drug eruptions, Intertrigo, Periocular leukotrichia, Preauricular alopecia, Urticaria pigmentosa, Apocrine nevus, Follicular mucinosis, Lentigo simplex, Acquired pinnal folding, Feline auricular chondritis, Erythema multiforme, foreign body reactions, vasculitis, idiopathic nasal scaling in bengal cats