Nothing can throw you off your game like tiny white flakes on your shoulder in an all-black outfit. Well, dandruff is a common condition, and it is a recurring issue for many. Dandruff can be caused by a variety of factors, ranging from genetic to environmental. To put it simply, when too much fungus or bacteria accumulates on the oily parts of your scalp, it causes itching, which leads to flakiness. Summer can aggravate this condition if sweat accumulates on your scalp for extended periods of time.