What is ringworm?
Ringworm is a highly contagious fungal skin infection that gets its name from the characteristic red, circular rash that can appear on the skin. Though called “ringworm,” it is not caused by a worm as the name might imply. Instead, it is caused by various species of fungi called dermatophytes that live on the dead tissues of the skin, hair, and nails [1].
When ringworm infects the skin, it often leads to an itchy, red, scaly, circular rash. Ringworm can spread to other parts of the body from animals, people and contaminated materials. The most common areas for ringworm to infect are the arms, legs, scalp, feet (athlete’s foot), groin, and face, especially in warm, moist areas. Ringworm is very contagious and easily transmitted through skin-to-skin contact, sharing contaminated items, or contact with infected surfaces [2].
How do cats get ringworm?
Ringworm is highly contagious among cats. Cats typically get infected with ringworm through direct contact with an infected animal, person or contaminated object or surface (Source). The ringworm fungus lives on the skin and hair of infected carriers. Ringworm spores can be picked up by touching contaminated fur or by sharing grooming supplies with an infected cat.
Stray and shelter cats are at a higher risk of exposure since they come into contact with many other cats. Pet cats can pick up ringworm by interacting with an infected stray or at places like boarding facilities, grooming salons, and shelters if proper sanitation is not maintained. Indirect spread through contaminated surfaces like bedding is also common among cats in close contact. So ringworm can spread quickly in multi-cat households or crowded shelters once introduced.
Can humans get ringworm from cats?
Yes, humans can get ringworm from cats. Ringworm is a fungal infection that is highly contagious and can spread from infected animals to humans through direct contact. While any age can get ringworm, children are more susceptible as their immune systems are still developing (Blue Cross).
For a human to catch ringworm from an infected cat, there must be direct contact between the human’s skin and the infected animal. Ringworm spores live in an infected cat’s hair and dead skin cells and are transferred to humans by touch. If a person pets, handles, or snuggles with a cat that has ringworm, they risk becoming infected themselves (California Department of Public Health).
However, as long as a person’s skin remains unbroken, the risk of infection is low. Risk increases if the skin is cut, scraped, or scratched. Children often have more direct contact with pets and more vulnerable skin, making them more prone to infection.
What are the symptoms in humans?
The most common symptom of ringworm in humans is a circular, red, itchy rash that develops 4-10 days after exposure. The rash is often located on the hands, arms, legs, scalp or feet, but can appear anywhere on the body. According to the CDC, the rash begins as a small scaly patch that expands outward, leaving normal looking skin in the center, creating the characteristic ring-like appearance that gives ringworm its name.
The rash may be accompanied by symptoms like scaling, cracking, swelling and blisters. The CDC notes that ringworm on the scalp can cause hair loss in the affected area as well. The rash is often itchy and uncomfortable. Severe itching and reddening of the skin around the ringworm lesions may also occur.
Sources:
https://www.cdc.gov/fungal/diseases/ringworm/symptoms.html
https://www.mayoclinic.org/diseases-conditions/ringworm-body/symptoms-causes/syc-20353780
How is ringworm diagnosed?
Ringworm is often diagnosed through a visual examination of the rash by a doctor. The doctor will look for the characteristic ring-shaped rash with a cleared center. If the diagnosis is unclear from a visual exam alone, the doctor may take a culture or skin scraping to test for fungus
A fungal culture involves gently scraping the affected skin and sending the sample to a laboratory to test for the presence of fungus. This can help confirm the ringworm diagnosis and identify the specific type of fungus causing it (1).
A skin biopsy may also be done where the doctor removes a small piece of the affected skin to examine under a microscope. This allows the doctor to look for evidence of fungus infecting the skin such as hyphae and spores (2).
In addition to a visual exam, a fungal culture or microscopic exam of a skin biopsy can help definitively diagnose ringworm and guide appropriate treatment.
(1) https://www.cdc.gov/fungal/diseases/ringworm/diagnosis.html
(2) https://www.mayoclinic.org/diseases-conditions/ringworm-body/diagnosis-treatment/drc-20353786
How is ringworm treated?
Ringworm is typically treated with antifungal medicines like ointments, creams, or pills. Some common topical antifungal creams prescribed include miconazole, clotrimazole, and terbinafine. Oral antifungal pills such as itraconazole or terbinafine may be prescribed for severe or resistant cases [1]. For scalp ringworm, oral antifungal treatment is usually needed.
With proper treatment, ringworm symptoms often start improving within 4 weeks. However, it is important to continue using the antifungal treatment for an additional 2 weeks after the rash has cleared up to ensure the fungus has been eradicated completely [2]. Using the medications for the full duration as prescribed is key to getting rid of ringworm permanently.
How can you prevent ringworm?
There are several steps you can take to help prevent ringworm:
- Avoid touching infected animals. Ringworm spreads easily between animals, so limit contact with any pets that show signs of infection [1].
- Maintain good hygiene. Wash your hands frequently, especially after touching animals. Keep your skin clean by bathing or showering daily [2].
- Don’t share personal items. Avoid using towels, clothing, brushes, and other personal items of someone with ringworm. The fungus can spread on shared surfaces [3].
- Keep skin clean and dry. fungi thrive in warm, moist environments. Dry your skin thoroughly after bathing and use powder to absorb moisture.
Practicing good hygiene and limiting skin-to-skin contact with infected individuals can reduce your chances of developing ringworm.
How long does ringworm last?
The ringworm rash typically lasts around 2-4 weeks with proper treatment, though it can take longer to fully clear in some cases. The rash remains contagious for the entire duration. This is because the fungal infection lives in the skin, even when treatment has started killing it. Fungus can also survive on contaminated surfaces for up to 3 weeks (KidsHealth).
It’s important to continue using antifungal creams or oral medications as prescribed, usually for 4 weeks or longer, until the rash is completely gone. Otherwise, ringworm can recur. You should also continue diligent hygiene and cleaning of clothes, towels, and bedding during treatment.
Once the rash has fully resolved, a person is no longer contagious. However, they can get ringworm again in the future if exposed to fungal spores.
When to see a doctor
In most cases, ringworm can be treated at home with over-the-counter antifungal creams. However, you should see your doctor if:
- The rash spreads or worsens despite using antifungal treatment
- You have a weakened immune system from conditions like HIV/AIDS or from taking immunosuppressant medications
- Signs of a secondary infection develop, like pus, increased pain, swelling, fever, or redness around the rash
People with weakened immune systems are at higher risk for the fungus spreading internally or developing a widespread rash. Seeking prompt medical care is important to get prescription oral antifungal treatment and ensure the infection does not worsen.
Signs of a secondary bacterial infection require antibiotic treatment in addition to antifungals. Left untreated, secondary infections can be serious. Your doctor can diagnose a secondary infection and prescribe appropriate antibiotic treatment.
If the rash continues spreading or fails to improve within a few weeks of using over-the-counter antifungals, see your doctor for evaluation. You may need prescription strength topical treatments or oral antifungal medication.
Key takeaways
Ringworm is a common fungal skin infection that can spread from cats to humans. While it may sound concerning, ringworm is treatable with proper medical care. The key things to remember are:
- Ringworm is very common, especially among cats, but can be cured with antifungal medications.
- Cats can carry ringworm without symptoms and spread it to humans through direct contact.
- If you think you were exposed to ringworm from a cat, watch for symptoms like ring-shaped rashes and see a doctor.
- With treatment, ringworm symptoms will clear up in humans within a few weeks in most cases.
- Practice good hygiene and sanitize environments to avoid spreading ringworm to others.
While ringworm may seem scary at first, try not to panic if exposed. Seek medical treatment and take precautions not to spread it further. With proper care and precautions, ringworm can be effectively managed and cured.
