Arm pimples are often caused by an unhealthy lifestyle. People who eat diets high in fat and low in fiber and complex carbohydrates are more at risk to get arm pimples. Your skin is an organ, and it reflects how your body is doing internally. If you are taking care of your body, eating healthy, being cleanly... You are going to look pretty good on the outside.
A couple of basic tips on how to keep arm pimples from popping up:
1. Cut the fat! A high fat diet, especially saturated fat, can be a leading cause of pimples in general. Avoid red meat and whole milk in particular, the fat and saturated fat content on these two foods can add up very quickly.
2. Drink plenty of water! Drinking lots of water does good things for your health in general, especially when it comes to acne. Go for at least 8 cups a day. Replacing soda with water will do wonders for your body inside and out.
3. Be sanitary. Make sure that you are cleaning your arms well at least once a day. This will help prevent dead skin cells and dirt, two main ingredients to the acne formula, from appearing.
Treating arm pimples is really not that much different then treating any other type of pimples. Use whatever acne treatment that usually helps with your acne and apply it liberally. Make sure to do everything that you can to not pop the pimple though, these types of pimples leave scars much more often pimples on one's face.
Arm Pimples [http://poppingpimples.org/2009/07/07/arm-pimples/]