Hi,
How are you? Intertrigo or inflammation in warm, moist areas of the body where skin surfaces rub or press against each other. It is caused by moisture, bacteria, yeast, or fungus in the folds of the skin and may present with pink to brown skin and may even break down and have a foul odor. Keeping areas of folded skin open and dry may help. Loose, nonrestrictive clothing should also be worn.If it persists, have this evaluated further by your doctor for proper management. Your medical history and some tests may be done such as a skin scraping and KOH examination to rule out fungal infection. A Wood's lamp will rule out a bacterial infection. Treatment will depend on the underlying cause. Take care and do keep us posted.
I would try Desitin, the same ointment used for a baby's diaper rash. You may have diaper rash without the diaper. Let us know what happens.