Trichomycosis: Overview and More

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Trichomycosis is a mild bacterial infection that mainly affects the axilla, also referred to as the armpit. Other areas of the body, such as the scalp, genitals, or buttocks, can also be affected.

While the infection itself isn’t serious and often comes without any symptoms, it can be uncomfortable. How common the infection is isn't known since it is not often reported due to a lack of symptoms.

This article discusses symptoms and causes of trichomycosis, as well as how it is diagnosed and treated.

Woman touching her armpit

Pongsak Tawansaeng / EyeEm / Getty Images

Trichomycosis Symptoms

While many people with trichomycosis experience no symptoms at all, symptoms can develop. The symptoms are not severe and can cause mild discomfort in the armpit area, the groin, or the area between the buttocks.

Signs of infection from trichomycosis include:

  • Sweating in the area that can be yellow, black, or red
  • Underarm odor
  • Small masses formed around the hair shaft (can be red, yellow, or black, and look similar to beads)
  • Hair that becomes rough in texture
  • Hair loss, in rare cases

Trichomycosis isn’t severe or serious in nature, and there are no complications associated with the infection.


Trichomycosis is caused by a type of bacteria known as coryneform-actinomycetes. The bacterium is referred to in medical literature as Corynebacterium tenuis.

While the infection itself generally isn't passed from person to person, there are some risk factors that make it more likely for someone to get it. These risk factors include:

  • Hyperhidrosis, or excessive sweating of the underarms
  • Living in a humid environment, such as a tropical climate
  • Poor personal hygiene
  • Obesity

Can Shaving Your Underarms Prevent Trichomycosis?

Since bacteria target the hair in the armpit, shaving can help reduce your risk of getting trichomycosis.


Many people don’t notice they have trichomycosis, and diagnosing it doesn’t come with any specific test. Typically, your healthcare provider will conduct a physical exam to check for signs such as the red, yellow, and black bead-like nodules that appear on the hair shaft and other signs of infection.

If more information is needed to make a diagnosis, a solution of potassium hydroxide will be used to help determine if the bacterium is present on the body.

In some cases, a wood’s light exam will be used. This type of test utilizes ultraviolet light to identify the colonization of bacteria on the skin.

Does Trichomycosis Get Worse If It Goes Untreated?

While the infection itself won’t become any more severe, it can spread to other parts of the body if it is not diagnosed and treated.


Treating trichomycosis is a simple process that begins with shaving off the affected hair. Following the removal of hair, antibiotic creams, ointments, or powders may be used to help ensure that bacteria are eliminated from the area.

The antibiotic typically used is erythromycin. However, other types of antibiotics, such as clindamycin, may be used, as well as antifungal medication known as clotrimazole.

Trichomycosis Prevention

Once the infection has cleared, you can use drying powders and ammonium chloride to stop excessive sweating. This should help ensure that the infection doesn’t return.


Trichomycosis is a mild infection of the hair under the armpit caused by Corynebacterium tenuis bacteria. While it typically presents with no symptoms at all, trichomycosis can cause the hair in the area to feel rough, and it can cause excessive sweating. Perspiration can be yellow, red, or black, the same color as the bead-like nodules that may form around the hair shaft in the affected area.

There are no serious side effects of the condition. The easiest way to diagnose it is by examining the area. Treatment involves shaving off the hair and possibly using antibiotic creams until the infection has cleared.

A Word From Verywell

People may have trichomycosis and not even know it. While it's scary to think you might have an infection and not be aware of it, having trichomycosis is not serious and doesn't do any harm to your health. If you suspect you have the infection, make an appointment with your healthcare provider. A provider will be able to diagnose the condition so you can begin easy and effective treatment.

Frequently Asked Questions

  • Does trichomycosis smell?

    Sometimes. Trichomycosis can lead to smelly underarms if a person has the infection. Not many people realize they have it at all, though, in which case it does not cause an odor.

  • Is treatment for trichomycosis the same in all areas of the body?

    While the infection typically occurs in the armpits, it can spread to the genital area and between the buttocks. If it does travel to these areas, the treatment course is the same. You will be required to shave the area and potentially use antibiotic creams to rid your body of the bacteria.

  • What color sweat can you have with trichomycosis?

    While not all people will experience a change in the color of their sweat, some might. In the event that they do, the sweat can be either black, yellow, or red, which can stain clothing.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Bonifaz A, Váquez-González D, Fierro L, Araiza J, Ponce RM. Trichomycosis (trichobacteriosis): clinical and microbiological experience with 56 cases. Int J Trichology. 2013;5(1):12-16. doi:10.4103/0974-7753.114704

  2. Zawar V. Photoletter to the editor: Trichomycosis (trichobacteriosis) axillaris. J Dermatol Case Rep. 2011;5(2):36-7. doi:10.3315/jdcr.2011.1071

  3. DermNet. Trichomycosis axillaris.

  4. Bonifaz A, Váquez-González D, Fierro L, Araiza J, Ponce RM. Trichomycosis (trichobacteriosis): clinical and microbiological experience with 56 cases. Int J Trichology. 2013;5(1):12-16. doi:10.4103/0974-7753.114704

By Angelica Bottaro
Angelica Bottaro is a professional freelance writer with over 5 years of experience. She has been educated in both psychology and journalism, and her dual education has given her the research and writing skills needed to deliver sound and engaging content in the health space.