What is Trichophyton Tonsurans?

Trichophyton tonsurans is a fungus that causes ringworm on the scalp. It was first discovered by David Gruby in 1844. It causes infections worldwide, although it is especially prevalent in Brazil, Mexico, and Africa. More recently, infections are being increasingly reported in the United States and Canada over the past few decades.

This fungal infection is usually associated with homes, schools, and barbershops. It can become transmitted directly or through pillows, couches, rugs, and pets. Infection may even occur through contact with an asymptomatic carrier.

Symptoms of Trichophyton Tonsurans

The most common symptom of Trichophyton tonsurans is what’s known as scalp ringworm. Once infected with this fungal infection, hairs burst and curl, eventually resulting in black dots on the scalp. The fungus responsible for the infection can even produce melanin. In fact, melanin is essential for its survival.

When an infection is still relatively new, lesions have clear and raised borders. As the infection progresses, there is increasingly more hair loss, with the scalp eventually becoming coated in a scaly layer. Only short hair stubs will remain. This is why the infection is often called black dot ringworm.

Inflammation is also prevalent and can appear as edema, an abscess, or highly-inflammatory kerion. While hair may regrow, some scarring may persist.


Treatment of Trichophyton tonsurans can be done by using a topical antifungal shampoo, systemic antifungals, or both. When an infection is more severe, or complex, then oral therapy will have to be administered. Using selenium sulfide or povidone-iodine shampoos will be the most effective, and help prevent person-to-person transmission.


To prevent infection with this fungal infection, it’s essential to stay away from infected towels, and anything else infected that touches the scalp. Since this is sometimes difficult to ascertain, other ways to prevent infection are to avoid placing, or using, towels, linens, and clothing that has been in areas of prolonged high humidity, heat, and perspiration. Additionally, you can prevent infection by avoiding using towels that have been used by people other than yourself.


Fungal infections sometimes clear up on their own, although the application of antifungal shampoos can clear up infections within several weeks.

How Alliance Enviro-Tech Can Help

Trichophyon tonsurans is an increasingly common scalp infection in humans. However, maintaining good hygiene reduces the risk of an infection that can cause harm to your health. This is an infection that can generally be avoided by following proper lifestyle and hygiene procedures, such as avoiding extended contact between your scalp and infected towels. You will want to ensure that you are not placing yourself at risk of succumbing to this fungal infection. It is important to be aware of all potential ways fungi can spread in your home or office.

Alliance Enviro-Tech can disinfect both residential and commercial spaces thoroughly. Our Path-Guard® System and Path-Away Anti-Pathogenic Aerosol Solution® can kill Trichophoton tonsurans, as well as other fungi, bacteria, and viruses, in under five minutes, giving you peace of mind to know your place is a healthier space. Contact us to learn more about how we can help.