It affects most people on one or more occasions during their lives.
There are two main types of herpes simplex virus (HSV), although there is considerable overlap.
Type 1, which is mainly associated with facial infections (cold sores or fever blisters) Type 2, which is mainly genital First or primary attacks of Type 1 infections occur mainly in infants and young children, which are usually mild.
Type 2 infections occur mainly after puberty, often transmitted sexually.
The initial infection more commonly causes symptoms.
Infection spread The virus is shed in salvia and genital secretions, during a clinical attack and for some days or weeks afterwards.
The amount shed from active lesions is 100 to 1000 times greater than when it is inactive.
Spread is by direct contact with infected secretions.
Minor injury helps inoculate the virus into the skin.
The virus can be inoculated into any body site to cause a new infection, whether or not there has been a previous infection of either type.
The source of the virus may be from elsewhere on the body especially in nail biters or thumb suckers.
Recurrent herpes simplex After the initial infection, whether obvious or unapparent, there may be no further clinical manifestations throughout life.
Recurrences are more frequent with type 2 genital herpes than with Type 1 oral herpes.
Recurrences can be triggered by: ·Minor trauma to the affected area ·Other infections including minor upper respiratory tract infections ·Ultraviolet radiation (sun exposure) ·Hormonal factors (in women, flares are not uncommon prior to menstruation) ·Emotional stress ·Operations or procedures performed on the face ·Dental surgery In many cases no reason for the eruption is evident.