Infections and infestations

THIS group of diseases is extremely common and no one goes through life without some infection of the skin at one time or another. In hot countries it is even more of a problem. An infection is caused by tiny organisms such as bacteria, viruses sand fungi and can spread from one person to another. 
They are microscopic. An infestation, on the other hand, is caused by small creatures that can generally be seen with the naked eye.
Many of the microbes which cause infection are present in our everyday environment without causing trouble. Why then do they sometimes produce a disease? The answer is not simple but depends partly on the immunity or resistance of the individual. For instance, people with recurrent cold sores find they often have an attack during a cold, when they are very tired or ‘run down’, after an accident or under a lot of stress.


 Avoidable conditions
It is commonly thought that many skin diseases are dirty, or in some way show that the sufferers do not look after themselves. This is far from the truth. Anyone can get boils, anyone can get athlete’s foot, anyone can get scabies, although overcrowding makes scabies commoner and those with poor hygiene may be worst affected. To a large extent whether you get any of these infections depends on inherited factors such as your natural resistance, luck and how sensible people are. For instance, someone with an active cold sore should not kiss people; those with athlete’s foot or other forms of ringworm should not lend their towels.


Bacteria Impetigo


This may be due to bacteria called Staphylococcus or Streptococcus or to both of them. Compared to a hundred years ago we see very little of this disease, probably because of increased standards of hygiene and nutrition. Only certain strains of these microbes will produce the disease whereas other strains may live harmlessly on the skin. Some people harbor the disease-producing strain in the nostrils and from there it can spread to infect a scratch or a bite or graze, etc.
It used to be common in rugby players and was known as one type of scrum pox. Transfer to other players was frequent. Another situation is people with atopic eczema ho have very itchy skin – these individuals scratch a lot and impetigo often develops as a secondary event.

Very often the Staphylococcus lives in their own nose or around the genitals and anus. It is therefore important to avoid picking or scratching these areas because it will transfer the Staphylococcus to other skin areas.

Your doctor may prescribe antibiotics for a nasty boil and a carbuncle will probably need to be opened more than is possible with a needle. He or she may advise nasal antibiotics and antiseptics in the bath to clear the staphylococci from your skin.

It may be necessary to treat the family in the same way because the bacteria quickly spread from one person to another. The final point is that people with recurrent boils sometimes have a lowered resistance and this should be checked.



Infections and infestations
Infections and infestations



Viruses are even smaller than bacteria and fungi and they are not usually found on normal skin. Many viruses can cause a rash – e.g. measles and glandular fever – but these diseases are not dealt with here. This section describes some virus infections in which either the only signs or the commonest signs of the disease are on the skin.



It is now known that there are several strains of wart virus and each tends to produce its own type of wart. Some cause the ordinary wart on the hands, others painful warts on the feet; and still others on the lace or genitals. Warts are caught from other people. This happens easily in children who have not had time to develop immunity to the virus but adults are more resistant. Even when the virus has gained access to the skin it may lie dormant for weeks or months before the wart itself appears.
Common warts are most frequently seen on the hands, fingers and knees. These may be one or many and a group may form into a large single wart. Because the virus spreads most easily into damaged skin it can take hold around the nail in nail biters: the appearance of multiple warty masses growing round many nails is typical of nail biters and pickers or people who manicure their fingers to excess.
Plane warts are almost flat and smooth and are colored like skin or slightly gray-brown. In some lights they may be difficult to see at all.

Most often affected are the backs of the hands, face and shins and in some instances large numbers may be found.
Filiform warts are slender, pointed warts often occurring singly usually affecting the face, eyelids or nostrils.
Plantar warts commonly known as verrucae, are found on the soles of the feet. There may be one or several. One type looks like multiple verrucae grouped together and is called a mosaic wart. Plantar warts are often picked up when the feet or floor is wet at swimming baths or showering after sport. Sometimes they are painful when walking. Another painful lump on the foot is a corn and this has a different treatment. Corns have a smooth surface and the normal pattern of skin markings (dermatoglyphics) is preserved. To distinguish the two a doctor or chiropodist may trim the surface with a scalpel and find that only warts have little black specks on the surface.

Rarely a wart may be removed under local anesthetic or injected with a drug which kills the virus. Fortunately, this is rarely needed.

Genital warts are nearly always sexually transmitted and require a different line of treatment. This should include an examination of sex partners as well as looking for other sexually-acquired diseases. Virus methods of treatment may be tried but it has to be regular and under supervision of a doctor.


Molluscum contagiosum

This is another common viral infection, sometimes referred to as ‘water warts’. It is usually children who are affected and particularly those who had a tendency to eczema. The tiny spots are a whitish color and when looked at through a magnifying glass can be seen to have a small dimple in the centre – like a doughnut. Multiple spots often appear and there may be some at different stages of development. Scratching fingers may spread the infection.

Treating warts
The treatment of warts depends on the age of the individual and on the type of wart. Wart paints are-the mainstay for common and plantar warts and when used properly are simple keratolytics, containing salicylic acid, which will gradually dissolve away the bulk of the wart. The wart is an overgrowth of keratin in response to the virus. The wart is an overgrowth of keratin in response to the virus. Salactol, Duofilm and Verrugon all work in this way.


Cold Sores

Herpes simplex is the name given to an infection of the skin caused by a herpes virus. It is seen most often on the lips and face and called a cold sore. Almost anybody site can be affected including the fingers and the eyes. Genital herpes is due to the same virus but it only be mentioned briefly here. ‘With all herpes there is a so-called primary infection that may cause fever and general ill-health for few days. After that the infection may reappear, at the same site, in the rest of life. The virus remains in the nerves supplying that part of the skin and can be reactivated by a number of factors, e.g. acute illness, sunlight, injury. The attack is often preceded by a few hours of a day of localized burning and tingling. The infection then appeared on the skin as small blisters on a red base in roughly the same place each time. They last for about four days, dry up and disappear without a blemish.

There is a specific treatment now available for herpes simplex the interferes with the replication of the virus. It cannot prevent further attacks but it can cut short the present one. Acyclovir (Zovirax is trade name) is more effective as tablets than as a cream. It is also reserved for people who have sever attacks and must be taken at first sign of itching or soreness to be effective. Genital herpes acquired sexually and while it is active you should not have sex without a condom.


Herpes zoster is the virus which causes both shingles and chickenpox. Having had chickenpox earlier in life the virus lives on close the spinal cord in the nerves which supply the skin. At a later date either when the resistance is low or for other unknown reasons. This virus spreads through the nerves and onto the skin supplied by the nerve. This explains why the rash is in a line, either down a limb or round the trunk. The attack is normally preceded for a day or two with burning or pain then the skin forms blisters on a red base that after few days become fulfilled before turning into scabs. There may be some scarring. It is most worrying when the eye is involved.

Shingles is usually an unpleasant experience although some people have little or no pain. All ages may be affected but it is far commoner in the elderly. It does recur like cold sores. It may, however, give rise to a pain called post-herpetic neuralgia which appears within week or two and may go on for months or years.

If the attack is recognized early the severity may be reduced if the doctor gives you acyclovir (Zovirax). However, if the blisters have been present for a day or two the medicine will be less effective.

Leave a Reply