The family herpes – introducing cold sores
Last month we were introduced to chickenpox and shingles, both caused by herpes zoster, and space prevented a close look at the other members of this family of viruses. This month is the turn of herpes simplex type 1 which is better known as the cold sore virus and which is a completely different entity from herpes simplex type 2 that causes genital herpes.
When I was a student and trying to remember lots of new information, it helped to link type 1 with one mouth producing cold sores around the mouth and type 2 with two testicles or two ovaries and producing herpes sores in the genital area. In those far-off days it was generally held that herpes simplex type 1 did not cross the waistline but that rule is now blurred with oro-genital sex and it is well known now for cold sore sufferers to infect their partner in the genital area and the first episode can be quite extensive and very painful. Not being aware of this risk can lead to suspicion, misunderstanding and incrimination within a faithful partnership and is ultimately sorted out with laboratory confirmation of the responsible virus. Unfortunately, as with all the herpes viruses, infection is permanent although recurrences can be treated with an antiviral such as aciclovir “Zovirax”
Typically cold sores arise around the mouth as the common cold is resolving and start as a tingling sensation under the skin at the site of the eventual small blisters which then go on to scab and heal – in all about 7 to 10 days from the onset of tingling and the virus can spread until the lesions are covered by scabs. Picking at the scabs can delay the healing and some Vaseline might soften the scab helpfully in the final stages. Sufferers are prone to have these recurrences throughout their lives. Sunlight can also precipitate cold sores on the lips and sunblock may help to stop a reactivation. Menstruation can also produce a recurrence and other common reasons are tiredness, stress and being run down or general illness. Being run down can lead to more extensive lesions in the mouth and throat and can be very painful, “like a mouth full of razor blades”, and can render the person very weak and with no interest in food or drink.
All these manifestations can be left to run their course without any treatment and they should resolve without a trace but the untreated episodes may last longer and cause potential prolonged embarrassment or undermine general well-being.
Treatment with acyclovir cream five times daily for five days can shorten the duration of an episode particularly if started as soon as the tingling sensation is felt. Aciclovir 200mg tablets (5 times daily for 5 days) can also have the same effect and may be more convenient for facial lesions in a hot climate or for infection in the mouth.
Sometimes the lesions become additionally infected with bacteria and the typical honey-brown crusting of impetigo becomes superimposed on the original lesion. This is very infective and can easily spread to other areas, and to other people, due to fingering and skin-to-skin contact. Bacterial infection usually responds easily to antibiotic creams (but not aciclovir) and justifies medical assessment to confirm the diagnosis.
Occasionally herpes cold sore virus gets in the eye and causes a nasty corneal infection with associated pain and redness in the eye. The invasion of the cornea by the virus produces a characteristic ulcer on the cornea which can be picked up by a doctor using fluoroscein eye drops. Clearly it is an important diagnosis to establish correctly and justifies a medical check. Aciclovir eye drops and tablets can then be used confidently to treat the episode and to avoid corneal scarring and possible damaged vision.
These days cold sore virus, herpes simplex type 1, is also found in the genital area and complicates the presentation of genital herpes which was traditionally caused by the last member of the herpes family, herpes simplex type 2 – more on this another time.
Dr Ken Prudhoe, MCA Approved Doctor, can be contacted at Club de Mar Medical Centre, Palma de Mallorca.