Felis ISSN 2398-2950

Symmetrical alopecia

Synonym(s): Feline Acquired Symmetrical Alopecia, Feline Symmetrical Self-induced Alopecia

Contributor(s): Martha Cannon, Rosanna Marsella, H Ellen Whiteley

Introduction

  • Alopecia of symmetrical distribution is a common presenting sign in cats.
  • In the majority of cases the alopecia Alopecia: overview is self-induced due to over-grooming, and reflects an underlying pruritic skin condition even in the absence of gross skin lesions. Behavioral causes of over-grooming occur less commonly. In either case owners may be unaware of the over-grooming, due to cats secretive grooming behavior.
  • Alopecia due to over-grooming (self-induced alopecia Psychogenic alopecia) can readily be distinguished from spontaneous alopecia: 
    • In self-induced alopecia, the short, sparse hair shafts which remain in the affected area will feel "stubbly" when they are stroked against the direction of hair growth. In cases of spontaneous alopecia the tips of the remining hairs will be fine and smooth when stroked "against the grain".
    • With self-induced alopecia the majority of the reminiang hairs in the affected area will be in the anagen (ie active) phase of hair growth, making them difficult to pluck out. In spontaneous alopecia hairs may be entirely absent; where they are present they are usually easily epilated.
  • Spontaneous alopecia is an uncommon cause of symmetrical alopecia. Possible causes include paraneoplastic alopecia Feline cutaneous paraneoplastic syndromes, follicular dysplasia/congenital hypotrichosis Congenital hypotrichosis Congenital hypotrichosis and alopecia, and telogen defluxion Telogen defluxion.
  • Alopecia of endocrine origin Skin: thyroid-responsive alopecia is extremely rare in cats.
    Print off the owner factsheet Over grooming (feline psychogenic alopecia) Over grooming (feline psychogenic alopecia) to give to your client.

Pathogenesis

Etiology

  • The majority of cases are caused by generalized pruritus. The cat responds by over-grooming, focusing on easily accessible areas.
  • Common causes of pruritus include flea allergic dermatitis    Flea bite hypersensitivity  , atopic dermatitis   Skin: atopic dermatitis  , and dietary hypersensitivity   Food hypersensitivity  . Other possible causes include cheyletiella   Cheyletiellosis  , dermatophytosis   Dermatophytosis  , and demodicosis (very rare in cats   Demodectic mange  ), cutaneous lymphoma.
  • Cats with FLUTD   Feline lower urinary tract disease (FLUTD)  may overgroom the ventrum, in response to bladder pain.
  • Behavioral over-grooming   Psychogenic alopecia   is usually a response to over-anxiety of any cause. Affected cats are frequently also suffering from mild skin pruritus which has initiated the behavioral over-response:
    • Cats spend 30-50% of their time grooming.
    • Grooming is a common displacement activity leading to the relief of stress.
    • Low grade stress induced grooming is harmless but cats can over groom due to continued stress and cause hair loss, skin damage and even mutilation of body tissue.
  • Alopecia of endocrine origin   Skin: thyroid-responsive alopecia   is extremely rare in cats.
    • Hyperthyroidism   Hyperthyroidism  may stimulate overgrooming resulting in symmetrical alopecia as described above.
    • Hyperadrenocorticism   Hyperadrenocorticism   is rare in cats and is more commonly associated with thin, fragile skin. Alopecia may also occur but mostly manifests as lack of hair re-growth at sites that have been clipped, rather than as spontaneous hair loss.
    • Acquired hypothyroidism   Hypothyroidism   is extremely rare in cats, it may result in spontaneous symmetrical alopecia but the diagnosis must be made with great care. Cats that are unwell for other reasons will have thyroid suppression (sick euthyroid syndrome) in the same way that dogs do.

Diagnosis

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Treatment

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Outcomes

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Gilbert S, Affolter V K, Gross T L et al (2004) Clinical, morphological and immunohistochemical characterization of cutaneous lymphocytosis in 23 cats. Vet Dermatol 15 (1), 3-12 PubMed.
  • Turek M M (2003) Cutaneous paraneoplastic syndromes in dogs and cats: a review of the literature. Vet Dermatol 14 (6), 279-229 PubMed.
  • Virga V (2003) Behavioral dermatology. Vet Clin North Am Small Anim Pract 33 (2), 231-251 PubMed.
  • O'Dair H A, Foster P (1995) Focal and generalized alopecia. Vet Clin North Am Small Anim Pract 25 (4), 851-870 PubMed.
  • Rhodes K H (1990) Cutaneous manifestations of canine and feline endocrinopathies. Probl Vet Med (4), 617-626 PubMed.

Other sources of information

  • Foster A P (2004) The Skin. In: Feline Medicine and Therapeutics. 3rd Edition. Eds E A Chandler, C J Gaskell & R M Gaskell. Blackwell Publishing pp 73-125.
  • Roosje P & Henfrey J (2003) An approach to alopecia in the cat. In: BSAVA Manual of Small Animal Dermatology2nd Edition. Eds Foster & Foil. BSAVA Publishing pp 71-76.
  • Scott D W, Miller W H & Griffin C E (2001) Feline Acquired Alopecias. In: Muller and Kirks Small Animal Dermatology. 6th Edition. W B Saunders Co. pp 901-912.
  • Scheidt V J (2000) Feline Symmetric Alopecia. In: Saunders Manual of Small Animal Practice. 2nd Edition. Eds S J Birchard & R G Sherding. W B Saunders Co. pp 375-380.


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