They are the consequence
of a viral infection normally in childhood. They generally appear
on the lips and nostrils but can be more widespread.
How do you catch them?
From directly touching a
cold sore, from kissing and from sharing common household objects
such as towels, cups and cutlery.
First signs are usually tingling,
burning or itching. Within around 24 hours blisters form which
can be very painful. In a few days the blisters breakdown into
shallow ulcers.
The cold sores are infectious from the early tingling stage up to the end of the ulcer phase. Healing is normally complete in 10 to 14 days.
In children cold sores can become infected with bacteria and develop impetigo.
After the first infection,
the virus lies dormant in the nerve which supplies the infected
area. The virus can be reactivated at any time to cause another
cold sore. Various trigger factors are: stress, fatigue, strong
sunlight, UV light from sun beds, menstruation or pregnancy and
generally when feeling run-down.