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Why do we promote such rash advice?

17/9/2015

 
I was listening to the radio in the car on my way to work and heard a story on the news which made me grind my teeth in frustration. The sound bite was encouraging students heading off to university to get vaccinated against meningitis, (all fine so far) then it went on to say how a rash that doesn’t disappear when pressed with a drinking glass is a feature of meningitis (ARGH!!). Not only is this information factually incorrect, I think it is also potentially dangerous.
no rash in meningitis
The rash of meningococcal sepsis is a particular “red flag” for the public and even some healthcare professionals; in meningitis teaching sessions to medical students, I am frequently told that a “tumbler test positive” rash is a feature of meningitis. Why is the “rash” used as a “poster boy” for meningitis awareness when in fact there is no rash with meningitis!?! The rash is a symptom of meningococcal sepsis, a totally different life-threatening clinical condition.

The confusion may lie in that it is the same bacterium but it is NOT the same condition... mutter, mutter... this all causes me undue irritation and frustration. Let me explain further. The symptoms and signs of meningitis and meningococcal sepsis are different:

meningitis vs menigococcal sepsis
Click for larger image
So how do you tell which children have meningococcal sepsis?
Many infections can present with rashes in children; most rashes in children are mild and self-limiting infections, others are rare in the era of vaccination, e.g. measles and rubella but some are serious e.g. meningococcal sepsis which kills quickly. So clearly it is imperative that you don’t miss a diagnosis of meningococcal sepsis! Consider it in all children with a fever and rash. The rash is a feature of meningococcal sepsis.

The main clinical features of meningococcal sepsis are the same as those of sepsis i.e. fever, tachycardia, hypotension, decreased conscious level, prolonged capillary refill time (a marker of shock) in addition to a rapidly spreading rash. The majority of rashes in children are not meningococcal sepsis but rather other infections (see below). 
differential diagnosis for infectious causes of rash illness in children
Click for larger image
So why can the misinformation of the “poster boy” non-blanching rash be dangerous?
The rash is a feature of meningococcal sepsis. I’ll say that again. The rash is a feature of meningococcal sepsis! People make the mistake of associating the rash with meningitis but this is incorrect, meningitis does not cause a rash. Because we have been brainwashed by the media into thinking meningitis should have a rash, it is possible to miss the meningitis and fail to treat it...the consequence is either brain damage or death. Meningitis does not cause a rash!

Can you have a blanching rash with meningococcal sepsis?
Yes you can! The non-blanching rash is a late feature of meningococcal sepsis and often by the time it is present the child is unlikely to survive. The rash of meningococcal sepsis always starts as a blanching rash. It may go through the blanching phase so quickly e.g. within a few minutes, that you don’t notice it but it does always blanch initially. In order to understand this you need to know why the rash occurs.

The initial phase of meningococcal sepsis involves the bacterium entering the capillaries that supply the skin. This causes a local acute inflammatory reaction which leads to erythema (redness) in the skin supplied by these capillaries. This localised erythema blanches. As the infection progresses the bacterium causes damage to the capillary wall and blood leaks out (extravasation) causing localised bruising, and then the blood vessel clots and the blood supply to the skin is blocked off leading to the skin dying (ischaemia). Both extravasation and ischaemia cause a non-blanching or petechial rash and at this stage the “tumbler test” is positive, but the patient is now very unwell and may not survive.

The rash presents with the blood stream infection not the meningeal infection. However it is possible to have both meningitis and sepsis and you can also have one without the other. If too much emphasis is given to the non-blanching rash then meningitis can be missed. Likewise if too much emphasis is placed on a non-blanching rash in meningococcal sepsis, then meningococcal sepsis treatment can be delayed.

I think the confusion occurs because both meningitis (no rash, but fever, headache, photophobia, neck stiffness) and meningococcal sepsis (fever, rapidly progressive rash, systemic symptoms) can be caused by the same bacterium, Neisseria meningitidis. They are different clinical conditions caused by the same bacterium.

Perhaps it is helpful to think about another bacterium, Staphylococcus aureus, which can also cause a range of different clinical conditions. Staphylococcus aureus can cause septic arthritis, osteomyelitis, cellulitis, pneumonia; all different clinical conditions caused by the same bacterium. Meningitis and meningococcal sepsis are different clinical conditions caused by the same bacterium, Neisseria meningitidis.

The other thing that seems to cause confusion is that the treatment is the same but this should not be confusing because the bacterium is the same...REMEMBER specific antibiotics kill specific microorganisms therefore the treatment of the same microorganism will usually be the same antibiotic.

Where did the “tumbler test” come from?
In the early 2000s there was a big push from public health to raise awareness of meningococcal sepsis in the general public. A lot of emphasis was put on parents recognising the petechial rash using the “tumbler test” by pressing a glass against the skin over the rash which will show whether the redness disappears or blanches. If the redness does not disappear then it is described as “non-blanching” or “petechial”. A much simpler way of testing for this is to gently press the skin away from the redness to see if it disappears. When I was doing paediatrics I would be told that the “tumbler test was positive” by referring doctors, as if this was some formal laboratory investigation! I have no problem with raising the awareness of meningococcal sepsis in the population but worryingly it is now known as a detection method for meningitis. This is wrong. A non-blanching rash is also somewhat unhelpful in meningococcal sepsis, as a non-blanching rash is a late diagnostic sign. More important is for parents and doctors to pay attention to “parental concern”, lethargy and a RAPIDLY SPREADING RASH regardless of whether it blanches, as these are far better early warning signs.

Historical Note: not so long ago paediatricians used to diagnose meningococcal sepsis by scratching one of the lesions and smearing the blood onto a glass slide for a Gram’s stain. This would show the blood to be packed full of Gram-negative cocci which would confirm the diagnosis. We don’t do this anymore; please send whole blood for PCR! 

So what do you need to know?
  • The differential diagnosis of a rash illness in children includes severe life-threatening as well as self-limiting infections and it is important to distinguish them
  • Meningococcal sepsis should be considered in any child with a rapidly spreading rash from a few minutes to a couple of hours, IRRESPECTIVE of whether the rash blanches or not
  • A rash is not a feature of meningitis and therefore do not fail to treat the patient’s meningitis because it is absent. 
  • Any patient who may have meningococcal sepsis should be given antibiotics as soon as possible which in primary care includes giving intramuscular Benzylpenicillin before they are transferred to hospital, this is often life-saving

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    Blog Author:

    David Garner
    Consultant Microbiologist
    Surrey, UK

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