what causes boils to suddenly appear?
<answer> Poor hygiene can cause  armpit boils. <context> Poor hygiene can cause armpit boils because of the dirt that is trapped within the hair follicle. Failure to bathe regularly can cause excess dirt, sweat and bacteria to collect under the armpit, causing a painful boil to appear. The boil may be either red or dark in color and is usually sensitive to the touch. According to the Better Health Channel, armpit boils may occur due to buildup of dead skin cells and bacteria on the skin under the arm.