[Echo-chan713]

Well there are a lot of factor played to it, I can only think a few right now as the following:

1. Stress can cause hormones to be active and one of those hormones inacted acne

2. The enviroment where all the dirt and the atmosphere can react to your skin differently.

3. Hygeine, at an area whaere water can be scare out in the hot weather bundled up in layers of heavy fabric can induce sweat which gets into the pores and with that can cause acne