Thanks for posting your query at Doctorspring.com. I can understand your concern.
This seems to be a bacterial infection of the hair follicle called folliculitis. It can happen in areas where there is sweat accumulation and occluded parts like body folds.
I would recommend application of mupirocin cream twice a day for a week when it occurs.
This will resolve the infection. But there can be a recurrence if the same environment persists.
Hence it is important the area clean and dry.
Please let me know if you have any queries.