Painful underarm odor may be caused by folliculitis, enlarged lymph nodes, and fox odor. It can be treated with topical antibiotics, antiperspirant and deodorant, and if necessary, through local injection or minimally invasive surgery. 1. Folliculitis: not paying attention to local cleanliness, low immunity, bacterial invasion of hair follicles caused by folliculitis, resulting in local pain and odor. Fusidic acid cream and mupirocin ointment can be given for topical application, antibacterial and anti-inflammatory treatment, which can promote recovery. 2. Enlarged lymph nodes: Infection can lead to enlarged lymph nodes, which can also cause underarm pain. You can take oral cefadroxil, cefixime, amoxicillin and other drugs to fight infection. 3. Fox odor: the odor in the armpit can also be considered to be related to fox odor. Sweat glands secrete a lot of sweat, and when the bacteria decompose the sweat, they produce an unsaturated fatty acid, which leads to a bad odor in the armpits. It can be treated with topical sweat suppressants such as aluminum chloride anhydrous ethanol solution, or through underarm injections of botulinum toxin. It can also be treated with minimally invasive surgery to remove the sweat glands. Underarm odor, pain, it is recommended to do a good job of local care, but also to the hospital dermatology department for examination, to understand the cause, targeted to give topical drugs, oral medication or surgical treatment, the specific use of medication need to follow the doctor’s instructions.