SmarTripÂ® Card. The SmarTripÂ® card is a permanent, rechargeable farecard that is safe and easy to use. Buy SmarTripÂ® cards online, at any Metrorail station, or at many convenient locations. You can set up an online SmarTripÂ® account to view your card balance and usage history, and register new cards.
Irritations and Allergic Reactions. External assaults to the skin can also cause formation of dark skin patches in underarm area. For example, chemicals in underarm products such as deodorants and antiperspirants are known for causing allergic reactions and irritations of the skin. Another type of external assault to the skin is excessive rubbing.
4. Antiperspirants. Regular use of antiperspirants can sometimes cause lumps under your armpits. This usually happens when you're allergic to or your body reacts to one of the chemicals used in your brand of antiperspirant. Treatment: The simple treatment is to change the brand and see how well the other works. If you get another pea-sized lump in armpit, you should stop using any type of antiperspirant at all.