I look at the endocrine system as playing an important role in helping with immune response and very necessary for it to be functioning well in illness of any kind.  Especially where it concerns the production of cortisol.   Cortisol not only helps to retain more fluid (being a mineralocorticoid) but also helps to raise the blood pressure which causes the blood to pump faster around the body to carry necessary immune proereties such as killer cellss which then eat the viral cells or invader cells.  Also to elimiante those from the blood quickly to avoid infection. 

So in illness you would have the immune sustem kicking in first in response to the increase in invader viral cells, but to continue to do it’s work properly it need for the endocrine system to do it’s part and to help increase the bodily fluids to do all that above.  Otherwise there will be a crisis.

In crisis, for children with CAH what happens instead is the opposite.  A drop in cortisol levels and aldosterone levels.  This is because usually they should increase and therefore a deficit is created when the excess available is being used up more quickly in the throes of an illness.  That is because the child with CAH only has enough cortisol for normal healthy day coverage.   Aldosterone production also steps up in illness so that the cells can retain more fluid and raise the blood pressure slightly.  This is so that we can carry more fluid to help flush toxins and carry the necessary compnents such as the killer cells as above. 

You would just have to imagine that the opposite (less cortisol) means less mineralocorticoids in such a scenario.  This then would cause the blood pressure to be less than what it needs to be--abd because it  needs to be somewhat higher, this of course is where a child may start to feel nauseous and sick.  There will also be more salt wasting effects such as diahorrea and possibly vomiting at that stage.   This means less fluid or blood volume and less ability to transport killer cells and macrophages (?) to where they need to be to fight off the virus or deal with the bacteria.    That is why the cortisol levels rise in illness--along with the temp. 

They do this as much in a viral illness as an infectious illness because in each scenario, it takes the increase in our blood volumes to carry the immune systems production of killer cells or macrophages which eat and devour viruses to rally to the cause and fight the virus.  Both need an increase in blood volume and blood pressure to rush these cells to where they need to be and erradicate viral cells as far as I understood it.   

That is why it is important to raise the cortisol levels of a CAH child in illness and accident.  The fluid retention steps up in illness and this is to help fight a virus or illness and without that the only fluid or blood pressure they are able to maintain is the same as they would on normal healthy days in mild illness.   Eventually though as they are unable to fight viruses, the viruses increase and the illness may become much worse.  I guess it would not be impossible for the viruses to be around for much much longer than they would normally be in a child who is able to have their adrenals act accordingly. 

 So when you say that holding off on the pamol can be ok in some fevers that may be all well and good for normal healthy kids.  However, to me that is an added complication to an already decreasing state in a CAH child.  One where you cannot afford to go.  Sometimes it is very stressful having a child that is sick or off colour--and it is bad enough without the having the worry of a temperature that jumps up or down or is raised permanently--whether just there in the background or not.  It is an obvious sign that things are not quite right and whilst in mild illness if we act quickly it can avoid the use of panadol, in serious illness where the temp goes up, we would never wait for it to spike as a fit and an adrenal crisis together (especially in the middle of the night when we may not be there) is not really a good idea.  It is far safer to be erring on the side of caution.  Having a fit and vomiting is not a good thing--well not where I would want it to go anyway.  In increasing the cortisol and the tylenol in my opinion the virus is over whether you use the tylenol or not, because in normal children you lower the temp and this affects their blood volume and blood pressure also I would imagine.  However, in CAH kids you raise the cortisol for them and this in turn raises the blood pressure and helps the body to do the rest.  Avoiding bringing down the temp in a healthy child may not be good as this induces a higher fluid intake and as they make aldosterone and cortisol perfectly they are well able to retain the extra fluid and have their blood pressure raise---but the tylenol would reduce that as I say.  In a CAH child because of them not being able to do the latter, in salt wasters they would actually start to waste some fluids and their blood volume plummets in the opposite direction---downwards as I said---so tylneol and cortisol in extra amounts helps them to be pain free, temp free and deal faster than an otherwise healthy child may anyway. 

In illness these changes happen on subtle levels and may be mild as in natalie’s daughter or they can be very exagerrated.  It all depends on the seriousness of the whole illness.    Certainly BOTH viral and bacterial illness should be met by an increase of cortisol in these kids (and I don’t care what any Doctor says---just to explain how things occur above is enough to know that this is what they really need to have happening for them in any illness mild or serious) as they will not do this by themselves.  Exactly what amount for any one child is impossible to determine as they all suffer with different severities but that is why we have the same basic protocol, because no one Doctor would really want to take a chance otherwise with any child with CAH.    The lab results at the next blood tests will often be out or skewif, but atleast the child has dealt with their illness and all is well again and that is all that counts when there has been a period of illness for a CAH child.