Title: Flea allergy dermatitis

{{short description|Skin disease of dogs and cats}}
[[Image:Flea allergy dermatitis.jpg|thumb|Dog with flea allergy dermatitis and secondary folliculitis]]
'''Flea allergy dermatitis''' is an eczematous itchy skin disease of dogs and cats. For both of these domestic species, flea allergy dermatitis is the most common cause of skin disease. Affected animals develop allergic reactions to chemicals in flea saliva. Symptoms of this reaction include erythema (redness), papules (bumps), pustules (pus-filled bumps), and crusts (scabs). If severe, hair loss will occur in the affected area. [[Dog]]s with flea allergy dermatitis often show hair loss and [[eczema]]tous skin rash on the lower back, upper tail, neck, and down the back of the legs. [[Cat]]s with flea allergy dermatitis may develop a variety of skin problems, including [[feline eosinophilic granuloma]], [[miliary dermatitis]], or self-inflicted [[alopecia]] from excessive grooming.&lt;ref name=&quot;:0&quot;&gt;{{Cite web|url=http://www.vetstreet.com/care/flea-allergy-dermatitis-in-cats-and-dogs|title=Flea Allergy Dermatitis in Cats and Dogs|date=April 22, 2014|website=Vetstreet|language=en|access-date=2019-08-11}}&lt;/ref&gt;

==Cause==
The flea found most commonly on both dogs and cats with a flea infestation is the cat flea, ''[[Cat flea|Ctenocephalides felis]]''.&lt;ref name=&quot;Sousa 2010&quot; /&gt; Flea allergy dermatitis is a hypersensitive reaction to antigens in the saliva of fleas. In some individuals just a single bite that cause a reaction.&lt;ref name=&quot;durden&quot;&gt;{{cite book | last=Durden | first=Lance A. | last2=Hinkle | first2=Nancy C. | title=Medical and Veterinary Entomology | chapter=Fleas (Siphonaptera) | publisher=Elsevier | date=2019 | isbn=978-0-12-814043-7 | doi=10.1016/b978-0-12-814043-7.00010-8 | page=145–169}}&lt;/ref&gt;
==Symptoms==
Animals with a hypersensitivity to flea saliva will develop a dermatitis characterised by [[pruritus]], [[papules]], self-induced partial [[alopecia]], and crusted skin in cats. Lesions develop on the medial hind limbs and the dorsal posterior area.&lt;ref name=&quot;durden&quot;/&gt;
==Diagnosis==
The diagnosis of flea allergy dermatitis is complicated by the grooming habits of pets. Cats in particular are very efficient at grooming out fleas, often removing any evidence of infestation. Fleas begin biting within 5 minutes of finding a host, and there are no flea treatments that kill fleas before biting occurs.&lt;ref name=&quot;Dryden 1994&quot;&gt;{{cite journal|last1=Dryden|first1=MW|last2=Rust|first2=MK|title=The cat flea: biology, ecology and control|journal=Veterinary parasitology|date=March 1994|volume=52|issue=1-2|pages=1-19|doi=10.1016/0304-4017(94)90031-0|pmid=8030176}}&lt;/ref&gt; 

==Treatment==
{{further|Flea treatments}}
The aim of treatment is to relieve the allergy-induced itch and to remove the fleas from the pet and its home environment.&lt;ref name=&quot;Sousa 2010&quot;&gt;{{cite book|last1=Sousa|first1=CA|editor1-last=Ettinger|editor1-first=SJ|editor2-last=Feldman|editor2-first=EC|title=Textbook of veterinary internal medicine|url=https://archive.org/details/textbookveterina00etti|url-access=limited|date=2010|publisher=Saunders|location=St Louis, MO|isbn=978-999606-2773|pages=[https://archive.org/details/textbookveterina00etti/page/n109 99]-101|edition=7th|chapter=Chapter 21: Fleas, flea allergy, and flea control}}&lt;/ref&gt; The majority of animals will lose their hypersensitivity to the antigen in flea saliva. In severe cases or to relieve symptoms more quickly, a [[pulicide]] is used. To treat the symptoms [[corticosteroid]]s are used.&lt;ref name=&quot;durden&quot;/&gt;

==See also==
*[[Dog skin disorders]]
*[[Cat skin disorders]]

==References==
{{Reflist}}

{{DEFAULTSORT:Flea Allergy Dermatitis}}
[[Category:Cat diseases]]
[[Category:Dog diseases]]