Rigors - Diagnosis

Authored by Dr Mary Lowth, 30 May 2017

Patient is a certified member of
The Information Standard

Reviewed by:
Prof Cathy Jackson, 30 May 2017

Very often, listening to the history of exactly what happened, together with careful examination, will allow healthcare professionals to diagnose the location of infection which is the cause of rigors. If this is the case then treatment can begin without the need for further tests.

A typical example of this would be if the doctor finds that your child has the rash and throat infection of scarlet fever, or if they see the red, bulging, painful eardrum of otitis media.

However, if the cause of the infection is not obvious - and particularly if your child seems unwell - then your child is likely to be sent to your local hospital for further investigation of the source of the infection. This is important, as any tests your GP surgery can do will not generate immediate results, and treatment is needed straightaway.

If you or your child are admitted to hospital, they will assume there is probably an infectious cause for the rigors. You will therefore be kept separate from other patients on the ward, to prevent transmission of infection. The tests that will be done depend partly on what they think is likely after examining you or your child.

  • All patients are likely to have blood tests. These look for signs of infection and help determine if it is a viral or a bacterial cause. Blood cultures look for bacteria circulating in the blood; these bacteria can be grown and tested to see which antibiotics will work against them. A blood sample may also be examined under a microscope to look for specific infections, such as malaria.
  • Urine testing is usual - urine will be 'dipped' to see if there are proteins or blood cells present, both of which suggest the possibility of infection of the bladder or kidneys - and then further tested to see what that infection might be.
  • Other tests which may be performed include:
    • Lumbar puncture (a sample of fluid from close to the spine, to look for meningitis).
    • Imaging using X-ray, computerised tomography (CT) scan or magnetic resonance imaging (MRI) scan to look for local signs of infection internally.
    • Ultrasound to look for conditions such as appendicitis, gallstones or kidney stones, and abscess.

It is likely that you or your child will remain in hospital until diagnosis and treatment have been decided upon. Sometimes treatment will be started whilst you are awaiting firm diagnosis, on the basis that the doctors may have an idea of the most likely infection that you are experiencing.

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