Tales from the Sanitorium

Perhaps you can detect the weakness and faintness of my voice as I type this from my sickbed, while recovering from whatever virus I caught. That's an RNA-type virus, not the computer-code type, which has colonised my pharynx. I think it's pharyngitis because this was the locus of the more unpleasant sensations, when I woke yesterday in a world of pain.

As usual, everyone else's ailments are intensely boring, while mine are fascinating. But I think I'll live through this one, not least because it's almost certainly the same virus that struck dear son DoDo down on Sunday, and he was back at school today, perky as a chipmunk.

So yesterday was spent in a haze of tissues, Trisha, Sally Jessie Raphael and Judge Judy. And a really looong day because every doze ended within half an hour in a heart-pounding dizzy sweat, with all limbs and especially the inside of my head aching. The throat was only really sore when I swallowed, but the muscle aching was there all the time.

Where do the headache and muscle aches of a virus come from? I should know this, and shockingly I do not. It's likely to be connected to inflammatory and pyrexial responses, but exactly where I'm not sure. By exclusion I can try to pin it down, a bit.

It's unlikely that the muscle aches represent local infection (viral infestation) in my muscles, which are healthy and functional. Instead, the pain is more likely to be due to a) circulating inflammatory factors in the bloodstream irritating nerve tracts in the peripheral nervous system or b) inflammatory factors in the brain, acting centrally where pain is perceived. Situation b) sounds dramatic and hypochondriac, but a mild viral meningitis is quite common, usually benign and self-resolving. However, I'll pass on the diagnostic test for viral meningitis (lumbar puncture with cloudy cerebrospinal fluid, raised white cells but no bacteria), as the treatment would remain the same- nothing except rest, fluids and Trisha.

CSF samples:



Another potential intermediate cause of headache and myalgia after a viral infection is the fever response, which raises body and brain temperature. Some of the cerebral changes seen with systemic infection are increases in substance P and delta-sleep inducing peptide.

Here's one of the few items I can find online to explain situation a).

MadSci Network: Immunology

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Re: Why do we get intense body aches when we have the flu?
Date: Fri Jul 6 17:39:15 2001
...
Common flu symptoms include fever, sore throat, muscle aches, shivers and cold sweats, etc. These symptoms are not caused by the virus itself but rather by our bodies' response to the the virus. The immune system mounts a two-fold response to the virus. The humoral response (antibody- mediated) produces antibodies that bind to influenza receptors, preventing further infection of uninfected cells. This is the primary means by which the influenza infection is arrested. The cellular response acts by destroying viral infected cells. This is where the nasty symptoms come from. T cells and macrophrages attack mucosal cells that have been altered by the virus and destroy them. The cells produce chemicals known as cytokines and interleukins that either destroy the abnormal cell or recruit other immune cells into the area that is infected. This cell- mediated response is intense and results in increased concentrations of the proinflammatory cytokines tumor necrosis factor (TNF), interferon gamma (IFN), and interleukin 6 (IL-6), which have been shown to parallel disease severity in clinical studies.(Hayden FG, Treanor JJ, Betts RF, et al. Safety and efficacy of the neuraminidase inhibitor GG167 in experimental human influenza. JAMA 1996;275:195-199.)

The specific cause of body aches (myalgia) are the interleukins, which are primarily produced by the macrophages. These interleukins cause pain, body aches, hypersensitivity of the nerves, etc. Some of the interleukins (such as IL-2) cause the fever seen during the flu, and probably the headaches. Since these interleukins are produced in response many different kinds of bacterial and viral infections, symptoms such as fever, myalgia, and headaches can be seen in infections by many different etiologic agents.

Damn those interleukins! They're nearly as bad a Blogger template and Haloscan comments.

My throat:

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