| Trichomycosis axillaris | |
|---|---|
 | |
| An armpit with variably encrusted hairs | |
| Specialty | Dermatology  |
Trichomycosis axillaris is a superficial bacterial colonization of the hair shafts insweat gland–bearing areas, such as thearmpits and the groin. It is a trivial disease of worldwide occurrence that is believed to be caused by the genusCorynebacteria.[1]
The condition has been calledtrichomycosis axillaris in literature extensively, but because it is a bacterial infection and not a fungal infection, its official name istrichobacteriosis.[2]
It is characterized by the presence of concretions along the hair shafts, clinically observed as yellow, and rarely as red or black nodules. These concretions derive from bacterial colonization along the hair shaft containing dried apocrine sweat with a cementing substance generated by the bacteria.[2]
It is caused by several species ofCorynebacterium.[2]
Obesity,hyperhidrosis, poor local hygiene, and warm, moist environments are common predisposing factors.[3]
The infection is diagnosed by close examination of the hair shafts where brown to yellow material called concretions are seen. There is usually an associated rancid odour. Amicroscopic examination can confirm the diagnosis, but this is rarely needed.[4]
Some patients with excessive sweating present the so-calledcorynebacterial triad, that is, the simultaneous presence of trichomycosis axillaris,erythrasma, andpitted keratolysis.[5]
No specific therapeutic studies on trichomycosis are available.[6]
Many authors consider that the most effective treatment consist in shaving of the affected area for a period of 2–3 weeks.[4][7] The use of aconcomitant treatment, such as sulfur soaps orbenzoyl peroxide[8] is also recommended.[2] Rubbing whilst washing may help to disrupt the biofilm, hence increasing the accessibility ofantiseptics to the bacteria.[6]
Patients who shave the affected area only once will generally experience a recurrence of the infection, since, the bacteria begin to develop the concretions once again as the hair grows back.[2]
Corynebacterium infections are related toexcessive sweating; for this reason, deodorants containing analuminum chloride solution may be used for treatment and prevention.[7]
Maintaining good local hygiene is recommended.[4]