Routine antibiotic treatment may be ineffective
According to the industry trade publication Nails,
mycobacterial infections appear initially as "pimply bumps that turn purplish, then seep and spread" into "ugly, pus-filled sores."
The sore or sores on the lower leg usually do not heal and may appear as thick, knotted areas that resemble a spider or insect bite.
A skin infection lasting at least two weeks may be a mycobacterial infection if it includes at least one of the following features:
Negative routine bacterial culture (taken by a physician or other appropriate medical professional)
Failure to respond to antibiotic treatment
The physician's suspicion of a mycobacterial infection
The time frame from exposure to observable infection is approximately three weeks to a month.
These infections contrast with the usually fast healing and non-scarring sores typical of folliculitis
. According to MayoClinic.org
, folliculitis usually appears as small, white-headed pimples around one or more hair follicles.
Folliculitis infections may itch but are not usually painful. Folliculitis often heals without treatment in a few days, but deep or recurring folliculitis may need medical treatment.