The Signs and Symptoms of Flea Bite Allergies in Humans

skin image by Robert Kelly from

Humans affected by flea bites can suffer from an allergic reaction to the flea saliva, known as flea allergy dermatitis. Dog and cats are commonly identified as flea hosts, but rodents, birds and small furry animals can also carry fleas.

If you believe your flea bites are from animals other than dogs or cats, your reaction may be more than just allergic, and you should see a doctor to eliminate the possibility of certain flea-transmitted diseases especially prevalent in developing countries.

Itchy Skin

While allergic reactions vary by individual, itchiness is one of the main symptoms of flea allergy dermatitis. All flea bites cause some itching, but those who suffer from flea allergy dermatitis experience a whole-body itching sensation. Children with allergic reactions may scratch until they develop open sores. Prevent secondary infections by applying an antihistamine and antibacterial cream to the skin regularly before covering the bites with bandages. To solve the problem, either have a professional exterminate the fleas or do it yourself using flea bombs, and apply spot treatment to your dog or cat immediately.


Flea bites leave a single, red bump, similar to a mosquito bite. However, sufferers of flea allergy dermatitis can experience an outbreak of hives surrounding the entire affected area, not just a single bump. The hives are swollen and sensitive, and frequent scratching exacerbates these symptoms.


A purple-red rash is another symptom of flea allergy dermatitis in humans. The rash may originate in the bite area, but can spread over the skin with persistent scratching. Apply a hydrocortisone or benzocaine cream to relieve the symptoms of itching, soothe the skin and help with flakiness.

Reaction Time and Length

An allergic reaction typically develops within 12 to 24 hours after the flea bite. The reactive symptoms last for approximately one week. If you have fumigated or otherwise eliminated the fleas and you or another person continues to display symptoms of flea allergy dermatitis, consult with a doctor to determine the cause and rule out other possible conditions.