Hair Thinning Above Left Temple, Is It MPB?

This does not sound like male pattern baldness. It sounds more like an allergic or irritant reaction. The result could be inflammation and even skin damage that is akin to a burn. Scalp inflammation can result in telogen effluvium or shock loss which can be temporary. This form of hair loss could be permanent if scarring occurs.

All this said, though, male pattern baldness is the leading cause of hair loss among men, and it can begin as early as 20 years of age. If you have a strong presence of male pattern baldness in your family history, it may be male pattern baldness initiated by a reaction to the oil or the friction of the comb you used to scrub. I suggest consulting your doctor or a hair loss specialist to figure out what's going on. 

If the hair does not return after six to eight months after the injury it is unlikely to return spontaneously.

Based on your question, it is nearly impossible to tell what is really going on with your hair. Your best bet is to have an in-person consultation at one of our local or regional offices.  At that time, we can discuss your medical and surgical options should this be male pattern hair loss.  If it is due to trauma, we can also take a look at what has happened and make recommendations based on the examination.  Good luck to you.