Infections

Infection is defined as a pathological state resulting from the invasion of the body by pathogenic micro-organisms. These pathogenic micro-organisms may be bacteria, viruses, mites or other less well known germs such as prions. “Germs” is the non-technical collective name for these organisms.

That’s all very well but doesn’t mean much to those people suffering from such afflictions as sinusitis, bronchitis, tonsillitis, pneumonia, meningitis, gingivitis, abscesses, boils, cellulitis, food poisoning or even honeymoon cystitis. Each of these is an example of infection which is or may be caused by invading micro-organisms. And the poor, unfortunate victims beat a well worn path to the doors of ED. The infections discussed here are representative of a much larger spectrum but this is not the right venue to try to describe them all – only a few.

I never cease to be amazed at the number of patients who present to us with cellulitis. Two or three in a shift is not uncommon. Cellulitis is a diffuse inflammation of the skin and the tissues immediately below the skin. It is an infection caused by common bacteria, such as staphylococci or streptococci, which gain entry through skin damaged by cuts, scratches, burns or other trauma. Sometimes it is an extension of a common boil and at other times there is no evidence of skin damage.

Diagnosis is usually easy. The patient presents with a painful, hot, red, swollen and very tender patch of skin. It can occur anywhere on the body but is most common on the legs. The glands in the lymphatic drainage area, e.g. groin or armpit, of the affected limb, are usually swollen and tender. It may be circumferential , that is, extending right around the affected limb. Often the patient has a fever and feels sick. There is a strong association with diabetes – especially insulin dependent diabetes and a stronger association with poorly controlled diabetes.

The management is straightforward. We ask about diabetes in the patient and family. If possible we take a finger prick blood sample and determine the blood sugar level. The infection requires aggressive treatment with antibiotics. Sometimes, especially when there are signs that the infection has spread beyond the skin, we take blood to culture for bacterial growth and other tests such as white cell count. Most often we give intravenous flucloxacillin, a modern and potent form of penicillin, because we know this is effective against the most likely causative bacteria. For an adult two grams is appropriate and this is followed up with oral capsules in a dose of one gram six hourly for at least five days. We usually mark out the limits of the inflamed skin with black felt tipped pen and ask the patient to not wash it off. If the inflammation extends beyond the marking then the treatment is not working and they must return to us. Rarely are these patients admitted to hospital but they are if surgery is indicated or they are particularly ill.

There are a few traps for young players in this. One mistake is to assume there is free pus under the inflamed skin and try to drain it by making an incision in the skin. This will only work if there IS free pus and it is pointing and fluctuant. That means the pus has formed a “head” or patch of white skin surrounded by red inflamed skin. This is usually extremely painful to touch. It will also feel like there is fluid under the white skin. If these signs are present then incision is mandatory and the pus is drained away. If these signs are absent then no pus will be evident and all that is achieved is a hole in the skin to add to the patient’s woes. Hippocrates had this one worked out. An immortal aphorism attributed to him is, “Ubi pus evactuo.” This translates, loosely, into English as, “Where ever there is pus I drain it.” Smart fellow! The flip side to that is, “if there is no free pus then don’t muck about with it”.

Another trap is to completely muck up the diagnosis. It is very dangerous to assume simple cellulitis and to not diagnose a compartment syndrome. They can both have much the same symptoms and signs but require careful differentiation. The compartment syndrome is one in which tissues, usually muscle, located in a confined space become inflamed and swell. But, because it is located in a confined space, the swelling is limited to that space and compresses blood vessels and nerves within the space. It is a surgical emergency requiring immediate decompression of the tissues by surgical incision of the confining tissues.

The forearm and the lower leg are commonly affected areas. The disease process may be initiated by surgery, trauma or even simply the repetitive overuse of muscles in athletics such as long distance running, cycling etc. Going back a couple of years I saw a middle aged woman with compartment syndrome in her forearm. She was an intravenous drug user. At the time she came into the ward the diagnosis was evident – rapidly increasing pain, swelling and tenderness in the forearm and severe pain with finger movements. The surgeon saw her within the hour and immediately took her to theatre by which time she could not move any fingers or the hand and morphine provided scant pain relief. A long, deep incision down the arm, through the skin and into deeper tissues, relieved the pressure and saved the limb.

Another, rare, condition that must be considered is necrotizing fasciitis. This condition took the fancy of the media a few years ago and was rather flamboyantly dubbed the flesh-eating disease. Untreated it can be devastating and result in the loss of limb and/or life. It is most often caused by a Type A Streptococcus but is sometimes caused by other bacteria or more than one organism. The bacteria gain entry beneath the skin via surgical or traumatic openings and then spread - not only beneath the skin but also down into deeper tissues. Severe pain, out of proportion to any wound or even cellulitis, (which may co-exist), is a hallmark and may be accompanied by fulminating, generalised illness and fever. Treatment is surgical excision of as much infected tissue as possible and high doses of antibiotics. However, the disease process causes blockage of small blood vessels which obstructs delivery of antibiotics to the infection and also causes the blood starved tissues to die with resultant gangrene.

Contrary to popular belief, there is nothing new about necrotizing fasciitis – it has been around for donkey’s years. A French venereologist, Jean-Alfred Founier who practiced in Paris from 1869 to 1902, described a particularly vicious form of it that occurs in the genital area of men. It may involve all or any of the penis, the scrotum and the perineum. (The perineum is the area of skin between the scrotum and anus.) Untreated it results in gangrene of the affected parts and severe, generalised illness and often a very ugly death. Curative surgery can be somewhat mutilating.

Much more common than compartment syndrome and necrotizing fasciitis are common boils and carbuncles. Again, there is a strong association not only with diabetes but also with obesity. When I was a kid – in the early 1940’s, most of us had boils from time to time. It was probably secondary to the poor diet we endured during World War Two when food was strictly rationed. In 1943 families were issued with books of ration tickets for butter, meat, sugar, tea, chocolate, petrol and clothing. Food was sent to the UK in large quantities and, of course, to Australia’s armed services in the various war theatres. I have digressed, but there is no doubt that poor nutrition jeopardises the immune system and hence resistance to infection.

Some obese young women seem prone to staphylococcal infections especially in the arm pits. They develop large boils that coalesce to form what are known as carbuncles. These very painful, large swellings are incapacitating and debilitating. Often, fluctuant pus can be felt under the skin without pointing. These girls are usually ill and require incision and drainage under general anaesthetic. This usually releases copious amounts of pus and relieves their symptoms. However, the incision must be kept open with a drain to prevent more pus building up under the skin. Regrettably, it is not uncommon to see the same girls present again with recurrences at the same site or elsewhere on the body.

Another, dangerous, form of infection is quinsy. It is a complication of tonsillitis in which the infection extends into the tissues around the tonsils and forms an abscess behind either or both tonsils. (An abscess is simply a collection or pool of pus within the body. The common boil is a form of abscess.) Untreated the abscesses can enlarge to the extent they push the tonsils together and block off the airway. They can extend into the deeper tissues of the neck. The infection can get into the blood stream causing septicaemia (blood poisoning). Quinsy, therefore, is a diagnosis that must not be missed. When it is diagnosed it becomes an emergency situation requiring urgent surgery and extremely careful monitoring of the patient’s airway and general condition in the interim. Treatment of quinsy is with surgery to open the abscesses and drain away the pus. Antibiotics are also given in large doses.

Wikipedia tells us that the first president of the United States of America, George Washington, died from complications of quinsy as did Pope Adrian IV. Not only that but the composers Georges Bizet (of Carmen fame) and Hector Berlioz both suffered it at least once.

Emergency Departments are plagued with dental problems including dental abscesses. It is not uncommon for dentists to direct patient to us for management of severe pain and/or obvious dental abscesses. And, of course, most tooth aches start after dental surgeries are closed or, at least, when they are fully booked for the next two weeks or so. Even patients who have had teeth extracted by dentists often present to us for pain management. But people in pain are patients regardless of the cause and require our best efforts.

The simplest solution to the pain of a dental abscess is to open the abscess and drain the pus. For reasons unknown to me dentists seem very reluctant to do this. We do it occasionally in ED if the abscess is pointing through the gums but often-times the abscess is not pointing and therefore cannot be drained by incision. It can, however, be drained by extraction of the tooth. A dental abscess can form inside the tooth pulp compressing the nerves that run through the pulp causing extreme pain and a sensation that the tooth is going to explode. Another form of dental abscess forms under the roots of a tooth. The pressure generated can actually force the tooth partially out of its socket with pain proportional to the pressure generated. In either case, the tooth must be removed because the abscesses will not heal with the tooth in place. And while the pain of toothache is well known to most of us the pain of a dental abscess can be excruciating. Occasionally it can be so severe we send the patient to a teaching hospital to be looked after by a facio-maxillary surgeon.

The use of antibiotics is mandatory in the treatment of dental abscesses for several reasons. One is that bacteria can escape from the abscess into the blood stream to cause septicaemia and/or bacterial endocarditis – an infection on the inner lining of the heart chambers and valves. A second is that the abscess can infect and destroy bone and cause sinuses (channels) to form in the bone and sometimes to even burst through the face. Even more serious is the propensity for dental abscesses, especially in the upper front teeth, to cause “cavernous sinus thrombosis”. This is a blood clot in a large vein that drains blood away from the brain and is usually fatal. Another serious complication of dental abscess is “Ludwig’s angina”. This is nothing to do with heart pain but is the spreading of infection from lower teeth into the glands under the jaw causing swelling and abscess formation there. This is a life threatening situation requiring urgent surgical treatment. (See the character sketch “Mick”.) In the days before antibiotics dental abscesses were a common cause of death through one or more of the complications described here.

Other forms of infection cause illness or death indirectly. For example, scarlet fever is caused by infection, often of the throat or tonsils, by bacteria known as streptococci. These bacteria produce a toxin that moves into the blood stream, circulated around the body and causes a rash, fever, illness and sometimes death. Tetanus is an infection caused by a bacterium – Clostridium tetani. It releases into the bloodstream toxins that cause paralysis of breathing muscles and violent spasms of other muscles. (Just the other night I sutured a wound on the foot of a young girl. Her mother refused permission for us to give her a tetanus immunisation because she had immunised her with homeopathic substances.)

The “Golden staph” germ that causes boils can also cause a particularly nasty form of food poisoning. The germ gets into food from an infection on a food handler and proliferates if the food is kept at room temperature for any length of time. It produces a virulent toxin, that is not destroyed by reheating the infected food. It causes vomiting, diarrhoea, cramping abdominal pains and malaise. These symptoms begin soon after the infected food is eaten – often as early as thirty minutes later. Fortunately the illness is rarely life threatening and is treated symptomatically – that is with fluid replacement, rest and medication to reduce cramping in the intestinal tract. Antibiotics are useless because they have no effect on the toxin. Strangely enough few people present to ED with food poisoning probably because the victims know what it is and treat it appropriately themselves.