Cat fleas (Cat flea) are tiny parasitic insects that feed on the blood of cats. Their scientific name is Ctenocephalides felis. Cat fleas are external parasites, meaning they live on the skin and fur of their host. They have specialized mouth parts designed for piercing skin and sucking blood.
While cat fleas prefer and thrive on domestic cats, they will also readily bite and feed on humans if given the opportunity. The bites can cause irritation and discomfort. In rare cases, flea bites can also transmit disease to humans.
How Fleas Get on Cats
Fleas go through four life cycle stages: egg, larva, pupa, and adult. Adult fleas live on the cat and feed on its blood. The female flea lays eggs, which fall off into the cat’s environment. Eggs hatch into larvae, which feed on organic debris. Larvae then spin a cocoon and develop into pupae. Pupae hatch into adult fleas that jump onto and bite cats, restarting the cycle. The full life cycle can take as little as 2 weeks.
Fleas spread by reproducing rapidly. A single female flea can lay up to 50 eggs per day. Eggs fall off the cat into carpets, bedding, and yards, leading to widespread infestation indoors and outdoors. Fleas can jump long distances to find a host. So even if your cat goes outside briefly, it can pick up fleas from the environment. Cats also get fleas from other infested pets and animals. Once a flea infestation starts, the life cycle perpetuates until treated.
[citation] https://entnemdept.ufl.edu/creatures/urban/occas/catflea.htm
How Fleas Transfer to Humans
Fleas cannot live on human bodies the way they live on cats and dogs. This is because fleas evolved to thrive on the fur and skin of animals, not humans. However, fleas can temporarily jump onto people and bite them.
Fleas are excellent jumpers. They can leap up to 8 inches high, which allows them to go from a pet to a person easily. When a flea bites a person, it is just looking for a blood meal and is not trying to set up permanent residence. After having its fill of blood, the flea will jump off and try to find another host, like a cat or dog.
Some sources of flea transfer from cats to humans include:
- Sitting with or petting an infested cat
- Napping with a flea-infested cat
- Brushing up against infested cat bedding or carpet
It’s important to understand that the fleas don’t stay on humans for more than a feeding. They cannot reproduce or live out their life cycle on human bodies. But they can give a temporary bite that may cause irritation or even transmit certain diseases in rare cases.
Cat Flea Bites on Humans
Flea bites on humans appear as small, red, itchy bumps on the skin. According to the Cleveland Clinic, flea bites can look like small red spots or may appear in clusters of red bumps [1]. The bumps are often surrounded by reddened haloes. Flea bites are extremely itchy and cause great discomfort, especially when fleas target areas like the legs and feet [2].
Flea bites can result in hives or rashes in people with flea bite allergy. The bumps may appear more purplish or bluish on some skin tones. Strong allergic reactions may cause a halo effect around the bite. Scratching the bites can lead to infection [3].
While flea bites themselves are not dangerous, they can facilitate the transmission of certain diseases in rare cases. It’s important to avoid scratching and treat the bites to prevent infection.
Diseases from Fleas
Fleas can transmit several diseases to humans, some of which can be serious or even fatal. According to the CDC, fleas are capable of spreading over 20 diseases [1]. Some of the most concerning flea-borne diseases include:
Plague – Also known as “Black Death,” plague is a rare but life-threatening bacterial infection transmitted by fleas. Symptoms include fever, chills, weakness, and swollen lymph nodes [2].
Murine Typhus – Caused by Rickettsia typhi bacteria, typhus produces a high fever, rash, and headache approximately 1-2 weeks after exposure [3].
Bartonellosis – Also called “cat scratch disease,” this bacterial infection causes swollen lymph nodes and fever after a flea bite. Bartonella bacteria are carried by cats and transmitted via fleas [1].
While rare, these flea-borne illnesses can be serious. However, the risk is relatively low for indoor cats and can be mitigated through preventative flea treatment.
Allergic Reactions
Some people can develop an allergic reaction to flea bites called flea allergy dermatitis (FAD). This occurs when a person becomes hypersensitive to the saliva in a flea’s bite. FAD can cause severe itching, red bumps, and rashes. The most commonly affected areas are the legs, arms, torso, and feet.
According to research, FAD affects humans when the cat flea Ctenocephalides felis bites a hypersensitive person who has been repeatedly bitten over time. The allergic reaction occurs in response to antigens in the flea’s saliva. Scratching and itching are common symptoms that can be quite uncomfortable and agonizing. In severe cases, dermatitis, hives, and skin lesions may develop (Youssefi, 2014).
Some symptoms of FAD include:
- Red bumps or rash at the bite sites
- Intense itching and discomfort
- Papules and crusting of the skin
- Hives or swelling at the bite sites
- Scabs from scratching
Allergic reactions to flea bites can range from mild to severe. Seeking treatment is important, as scratching can lead to skin infections. Anti-itch creams, oral antihistamines, medicated shampoos, antibiotics, or corticosteroid creams may help relieve symptoms.
Treating Human Flea Bites
The main treatment for flea bites on humans is relieving the itching and preventing infection. According to the Cleveland Clinic, over-the-counter anti-itch creams or ointments containing ingredients like hydrocortisone can help soothe itching and swelling from flea bites [1]. Antihistamines like Benadryl can also help relieve itching. Applying an ice pack wrapped in a towel to the bites can reduce inflammation too.
It’s important not to scratch the bites to avoid breaking the skin and risking infection. Keeping the bites clean and applying antibiotic ointment can prevent infection. If the bites become infected, see a doctor for evaluation and possible oral antibiotics.
For severe itching or swelling, a doctor may prescribe a stronger topical steroid cream. They may also give an injection of epinephrine if you have a systemic allergic reaction. See a doctor immediately if you have trouble breathing, chest tightness, or swelling of the lips or throat after flea bites.
While the bites usually clear up on their own within a week or two, your doctor may recommend additional treatment if there is excessive swelling, pus, spreading redness, fever, or you do not get relief from over-the-counter remedies [2]. Proper at-home flea control measures will also help prevent more flea bites.
Preventing Fleas on Cats
The best way to prevent humans from being exposed to cat fleas is to keep cats flea-free. Here are some tips for preventing fleas on cats:
- Use flea prevention products regularly. Topical spot-on treatments like Frontline or Advantage kill fleas and prevent reinfestation. Oral medications like Nexgard also work well (WebMD).
- Vacuum the house frequently to remove eggs and larvae. Focus on carpets, furniture, and pet bedding.
- Wash pet bedding weekly in hot, soapy water to kill fleas at all stages.
- Bathe cats periodically with cat-safe flea shampoo – but not too often, as this can dry out skin (PetSmart).
- Keep cats indoors as much as possible to limit exposure to fleas (CDC).
- Treat outdoor areas like the yard with sprays or powders that kill fleas.
By diligently using flea prevention on cats and treating the home environment, cat owners can help prevent flea infestations that lead to human exposure.
Treating the Home
To effectively get rid of fleas in the home, you’ll need to treat the environment in addition to treating any pets. Fleas can survive without a host for many months, so just treating your cat may not eliminate an infestation. Here are some recommendations for treating your home environment to kill fleas:
Vacuum all floors, furniture, corners and crevices daily. This will remove eggs, larvae, pupae and adult fleas. Make sure to throw away the vacuum bag after use. Steam cleaning carpets and upholstery before vacuuming can also help kill fleas.
Wash all bedding, throws, pillows and pet items in hot, soapy water. This will kill all stages of fleas.
Use an insect growth regulator (IGR) like methoprene or pyriproxyfen. IGRs prevent flea eggs and larvae from developing into adults.
Apply an environmental flea spray. Look for sprays with insect growth regulators (IGRs) and adulticides to kill all life stages. Spray carpets, furniture, pet beds, under furniture, baseboards and anywhere fleas may hide.
Consider hiring a professional exterminator if the infestation is severe. They have access to stronger and more thorough treatments.
Treat outdoor areas like patios, decks and under porches where pets spend time. This can help prevent reinfestation.
It can take weeks to fully clear an infestation. Be diligent and repeat treatments as necessary until all signs of fleas are gone.
When to See a Doctor
In most cases, flea bites are a nuisance but don’t require medical attention. However, you should see a doctor if you experience severe allergic reactions like difficulty breathing, nausea, hives, or swelling in the face or throat. These can indicate anaphylaxis, which is a life-threatening allergic reaction requiring emergency care.
You should also see a doctor if the bites become infected, which may happen if you scratch them excessively. Signs of infection include increased redness, swelling, pain, warmth at the site, and pus draining from the bites. A doctor can prescribe antibiotic creams or oral antibiotics to clear up the infection.
Those with weakened immune systems like young children, pregnant women, seniors, and people with chronic illnesses should also get medical attention for flea bites to prevent complications. Your doctor can provide stronger medications to relieve itching and swelling.
It’s advised to see a doctor if flea bites cover large areas of the body or if they do not improve with over-the-counter treatments. Bites that last longer than a few days or weeks may require prescription steroid creams or oral steroids to resolve. Your doctor can help determine if flea bites have progressed to a more serious rash or infection requiring medical treatment.