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 The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the gray wolf. Also called the domestic dog, it was selectively bred from a population of wolves during the Late Pleistocene by hunter-gatherers. ...

s with flea allergy dermatitis often show hair loss and

eczema Dermatitis is a term used for different types of skin inflammation, typically characterized by itchiness, redness and a rash. In cases of short duration, there may be small blisters, while in long-term cases the skin may become thickened ...

tous skin rash on the lower back, upper tail, neck, and down the back of the legs.

Cat The cat (''Felis catus''), also referred to as the domestic cat or house cat, is a small domesticated carnivorous mammal. It is the only domesticated species of the family Felidae. Advances in archaeology and genetics have shown that the ...

s with flea allergy dermatitis may develop a variety of skin problems, including feline eosinophilic granuloma, miliary dermatitis, or self-inflicted

alopecia Hair loss, also known as alopecia or baldness, refers to a loss of hair from part of the head or body. Typically at least the head is involved. The severity of hair loss can vary from a small area to the entire body. Inflammation or scarring ...

from excessive grooming.

Cause

The flea found most commonly on both dogs and cats with a flea infestation is the cat flea, ''

Ctenocephalides felis The cat flea (scientific name ''Ctenocephalides felis'') is an extremely common parasitic insect whose principal host is the domestic cat, although a high proportion of the fleas found on dogs also belong to this species. This is despite the wide ...

''. 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.

Symptoms

Animals with a hypersensitivity to flea saliva will develop a dermatitis characterised by

pruritus An itch (also known as pruritus) is a sensation that causes a strong desire or reflex to scratch. Itches have resisted many attempts to be classified as any one type of sensory experience. Itches have many similarities to pain, and while both ...

papules A papule is a small, well-defined bump in the skin. It may have a rounded, pointed or flat top, and may have a dip. It can appear with a stalk, be thread-like or look warty. It can be soft or firm and its surface may be rough or smooth. Some ...

, self-induced partial

, and crusted skin in cats. Lesions develop on the medial hind limbs and the dorsal posterior area.

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.

Treatment

The aim of treatment is to relieve the allergy-induced itch and to remove the fleas from the pet and its home environment. 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 Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are invo ...

s are used.

References

{{DEFAULTSORT:Flea Allergy Dermatitis Cat diseases Dog diseases

Cause

Symptoms

Diagnosis

Treatment

See also

References