FLEA-BITE HYPERSENSITIVITY AND FLEA CONTROL BASICS OVERVIEW
- “Hypersensitivity” is an increased sensitivity or reaction in the skin due to the presence of a foreign substance; in flea-bite hypersensitivity, the foreign substance is found in flea saliva; the reaction is immune based and would be considered to be an “allergic” reaction
- “Dermatitis” is the medical term for inflammation of the skin
- “Antigens” are substances that induce sensitivity or immune response
- “Flea-bite hypersensitivity” or “flea-allergy dermatitis”—hypersensitivity reaction to antigens in flea saliva, with or without evidence of fleas and flea dirt
- “Flea infestation”—fleas and flea dirt are present on the pet, with or without signs of flea-allergy dermatitis
- “Flea-bite dermatitis”—inflammation of the skin due to the flea bite itself; it is not an allergic or hypersensitivity reaction, but rather an irritant response to flea bites
GENETICS
- Flea-bite hypersensitivity—unknown inheritance pattern; more common in breeds with atopy (disease in which the animal is sensitized [or “allergic”] to substances found in the environment [such as pollen] that normally would not cause any health problems)
SIGNALMENT/DESCRIPTION of ANIMAL
Species
- Dogs and cats
Mean Age and Range
- Flea-bite hypersensitivity—rare in pets less than 6 months of age; average age range, 3 to 6 years, but may be seen at any age
SIGNS/OBSERVED CHANGES in the ANIMAL
- Depend somewhat on the severity of the reaction and the degree of exposure to fleas (that is, seasonal or year-round)
- Itchiness (known as “pruritus”)
- Compulsive biting
- Chewing (“corncob nibbling”)
- Licking, primarily in the back half of the body, but may include other areas
- Cats—scratching around the head and neck
- Signs of fleas and flea dirt; finding fleas and flea dirt is beneficial, although not essential, for the diagnosis of flea-bite hypersensitivity; sensitive animals require a low exposure to fleas to have an immune response and they tend to over groom, removing evidence of flea infestation, and making identification of parasites difficult
- Hair loss (known as “alopecia”)
- Small, raised skin lesions (known as “papules”)
- Darkened skin (known as “hyperpigmentation”) in dogs
- Thickening and hardening of the skin, usually associated with hyperpigmentation (known as “lichenification”) in dogs
- “Hot spots” in dogs
- Miliary dermatitis (skin inflammation characterized by numerous, small, crusty bumps) in cats
CAUSES
- Fleas
- Immune response to flea saliva (flea-bite hypersensitivity or flea-allergy dermatitis)
RISK FACTORS
- Flea-bite hypersensitivity—intermittent exposure to fleas increases likelihood of development; commonly seen in conjunction with atopy (disease in which the animal is sensitized [or “allergic”] to substances found in the environment [such as pollen] that normally would not cause any health problems)
TREATMENT HEALTH CARE
- Outpatient treatment
MEDICATIONS
Medications presented in this section are intended to provide general information about possible treatment.
