Genital herpes is caused by a virus, Herpes Simplex.
Herpes Simplex is in the same family of viruses as chicken pox, shingles and cold sores.

The Herpes Simplex Virus (HSV) has two forms, type 1, and type 2. Type one typically causes cold sores and lesions around the face, while type 2 most often causes lesions in the genito-anal region.

It can be easy rememberd as type one most frequently hits above the belt, and type two most often hits below the belt.

The herpes simplex virus is quite identifiable by its characteristic sore or lesion: A thin-walled blister on an inflamed base of skin, frequently painful.

However, other medical conditions can visually resemble herpes, and medical practitioners cannot base a herpes diagnosis on visual inspection alone.

Additionally, some patients infected by  the virus may not have visible genital lesions.

Laboratory tests are essential for confirming herpes diagnosis. These tests include virologic tests (which examine samples of skin taken from the lesion) and serologic tests, meaning blood tests that detect antibodies to the various types of herpes simplex virus.

Herpes being a viral infection means that anti-biotics will have no effect on the virus, the outbreak or symptoms.