Dr John Chia has noted that corticosteroids when given during an acute viral infection seems to be a "recipe" that can often precipitate ME/CFS. That is to say, quite often: acute infection + corticosteroids = ME/CFS In a presentation by Dr John Chia at the Invest in ME Conference, London 2010 (found on the DVD of the conference), Dr Chia talks about the factors and events his patients report just prior to their development of ME/CFS. From these meticulous investigations into his ME/CFS patients' medical histories, Dr Chia discovered that literally hundreds of his patients were given corticosteroids such as prednisone exactly at the time that they were acutely ill with a viral infection. From hearing this corticosteroids story hundreds of times over in his ME/CFS patients, Dr Chia concluded that taking steroids while fighting an acute viral infection seems to be a recipe for disaster, as it appears to greatly increase the risk that ME/CFS will be precipitated by the infection. Why might corticosteroids be inadvertently prescribed for a viral infection? Dr Chia says the skin rash that may be caused by an acute enterovirus infection can look like chicken pox, measles, German measles, or hives. Dr Chia says that if, for example, people suddenly become ill and develop a skin rash from an acute enterovirus infection, they may go to the emergency room, and the ER doctor will look at the rash, and might suspect the rash to be hives, since enterovirus rashes can look identical to hives. So the ER doctor will question the patient about what he ate beforehand. If the patient just happened to eat some shellfish, then the ER doctor may (incorrectly) assume that the patient's rash is a hives rash, caused by allergy to the shellfish, and so will put the patient on a course of steroids, like prednisone or prednisolone, as this is the normal treatment for hives. Thus the patient has an acute enterovirus infection, and needs a strong and robust immune response to fight this infection, yet receives immunosuppressing corticosteroids, because the viral rash was misdiagnosed as hives. Similarly, if a patient comes down with an acute viral infection and its symptoms are suggestive of asthma, they may also be inappropriately prescribed corticosteroids, because that is how asthma is treated. Dr Chia says on the video: Why might taking corticosteroids during an acute viral infection lead to ME/CFS? It is hard to say, but perhaps if you take immunosuppressive corticosteroids at a critical stage when the body is trying to fight off an acute enterovirus infection, these steroids may weaken the immune response and thereby allow the acute viral infection to spread more deeply into cells or tissues that the virus would not normally get the opportunity to infect when the immune response is strong. Once spread more deeply into these cells or tissues, perhaps an enterovirus may more readily set up a non-cytolytic infection; or in the case of Dr Martin Lerner's theory of herpesvirus ME/CFS, more readily set up an abortive infection in non-permissive cells, which like non-cytolytic infections, smolders away but produces no new viral particles. And once the virus has gained a foothold in these cells or tissues in this way, it may no longer be possible to eradicate the virus from the body. So this enterovirus infection never resolves, and it becomes a chronic infection (one which produces very few new viral particles, but persists in the tissues). The patient may then come down with ME/CFS a few weeks or months after. Dr Chia says on another video: So acute infection + corticosteroids = ME/CFS may explain the reason that a subset of patients developed chronic fatigue syndrome.