MEDICAL MATTERS: How to tell if it's a common cold or influenza
AS I prepare to write this week’s column its 4.30am. Needless to say that wasn’t the plan. Nor was this the topic I had in mind but as the saying goes: needs must.
I have been awake for about an hour with a fever, a nasty headache and a running nose. It’s the severity of the headache that won’t let me go back to sleep; an incessant pounding behind both eyes.
Paracetamol has had minimal effect on the pain, although it has settled the fever somewhat. Earlier in the night, I had a bout of shivering followed quickly by sweating.
At this time of year, and against a background of rising numbers of influenza cases in the country, the first, foggy diagnostic thought is that I have come down with the flu.
But I don’t have muscle aches all over my body, or a rubbery feeling in my legs and I have been able to get up and potter round.
Probably the main reason I am unlikely to have the influenza virus is that I am able to sit at the computer and write.
Leaving the quality of my efforts aside, the key diagnostic point is that if I had flu, I would be unable to lift my head from the pillow and the prospect of getting up and writing would induce a semi-delirious moan.
Another pointer against this being a true influenza infection is that the symptom onset was not abrupt, something that is quite typical of a full-blown flu. Patients will classically describe being at full tilt one minute and, literally, falling over an hour later.
So could I have the common cold? It’s certainly possible, although the fever goes against it. Caused by a wide range of viruses, each with multiple strains, adults get a cold two to three times a year.
They are usually self-limiting, and most of us will treat ourselves for the symptoms; only half of 1 per cent will go on to develop a secondary bacterial infection of the sinuses which may require antibiotic treatment.
But hold on: might that be what’s going on here? The pain behind the eyes could be linked to sinusitis. As I palpate around my forehead and maxilla, there are areas of tenderness, especially above the left cheekbone. And I do have a nasal discharge . . .
In any case, it’s time to stop this early morning bout of “physician heal thyself”. Later, I’ll go to see my GP and let him make some objective diagnostic and treatment decisions for me.
Latest figures from the Health Protection Surveillance Centre (HSPC) confirm we are in the grip of a seasonal influenza epidemic. It’s likely to worsen over the next two to four weeks, and then should begin to fade away.
Most victims will get back on their feet within a week to 10 days, but pregnant women and others with underlying chronic disease are at increased risk of certain complications.
Influenza gets its name from the Italian Renaissance when an outbreak of flu was thought to be due to the influence of a particular planetary alignment.
There are three types of flu virus: influenza A, B and C, and within each type lies the potential for millions of subtypes.
The main virus types in circulation this winter are influenza A (H1N1) 2009, influenza A (H3N2) and a subtype of influenza B.
Flu virus invades the cells of the human body by injecting a spike of its own cell wall into the cells of the respiratory tract.
It then begins to multiply, using the human cell as a new home.
The virus reaches the respiratory tract via droplets in the air, which come from the coughs and sneezes of other flu victims.
Influenza reproduces rapidly in the throat and the lining of the lungs. From these initial sites in the respiratory tract
it begins to invade the rest of the body by way of the bloodstream.
Talk of flu pandemics usually causes a frisson of anxiety. The 2009 swine flu pandemic produced a relatively mild illness and may even have thrown us off our guard to some extent.
However, descriptions of the Spanish flu and other pandemics since are a reminder of the devastating power of the virus as it sweeps around the globe.