How not to miss – meningitis

The term meningitis is often loosely used by doctors to refer to both meningitis and meningococcal septicaemia – the condition most commonly associated with an extensive non-blanching rash. Parents do not know the difference, and failure to appreciate this can lead to diagnostic and therapeutic errors

Worse outcome if missed

• Death – missing a diagnosis of meningococcal septicaemia puts the patient at risk of death
• Deafness and long-term neurodisability – delays in diagnosing meningitis are likely to lead to deafness and long term neurodisability or cognitive problems
• Skin scarring
• Amputation
• Medico-legal actions by parents – a serious problem for GPs is that missed cases of meningitis and septicaemia account for significant medico-legal actions by parents

Long-term survivors of both meningitis and septicaemia with complications have reduced quality of life, increased psychological problems and lower self-esteem as teenagers.

Epidemiology

The following bacteria are important causes of meningitis:

• Group B meningococcal disease – this remains a major problem in the UK as. A vaccine has achieved a license for the UK and Europe but has not yet been accepted as part of universal vaccination – it is currently under consideration. The vaccine will be available privately late in 2013. Infants and children under five years of age are most at risk from meningococcal disease. There is a secondary peak of illness in older teenagers who also have a higher case fatality rate than younger children.
• Streptococcus pneumonia – this causes meningitis in all age groups. The vaccine has proved effective against the relevant serotypes but disease continues to occur due to other serotypes.
• Neonatal meningitis – continues to be a significant problem. Group B Streptococcus can cause meningitis until three months of age. In the first two weeks of life other organisms such as E.coli are important. Listeria remains uncommon.

Symptoms and signs

Symptoms and signs vary depending on the age and whether the disease is predominantly septicaemia or meningitis.

Neonates

Symptoms can be very subtle. Fever only occurs in 50% of cases. Poor feeding, temperature dysregulation, lethargy, poor perfusion, irritability, altered cry can all indicate serious disease.

Meningitis

Neck stiffness and photophobia are very poor signs in children under five years of age. Even in children a bit older than this the absence of these signs does not rule out meningitis. All symptoms and signs of meningitis are those of raised intracranial pressure. Headache, irritability and vomiting are very common early presentations. Increasing lethargy and a fluctuating level of consciousness indicate increasing intracranial pressure. Reduced pulse rate, dilated pupils and altered breathing are serious signs of raised intracranial pressure as are visual disturbances, coma and seizures.

Septicaemia

The symptoms and signs of septicaemia are much more difficult to pick up than those of meningitis. The main reason for this is that patients tend to be alert and able to talk – this can be very falsely reassuring. Septicaemia leads to shock and multi-organ failure – loss of consciousness is a late and serious sign. Initially, children will have non-specific signs of fever, irritability, vomiting and generally being unwell. This prodromal period will be longer in older children.

Patients with sepsis get more unwell with every hour that passes. Parents tend to know their children are unwell but may not be able to explain why. Patients with shock will be pale with evidence of poor circulation – mottled skin, cool peripheries with prolonged capillary refill time, tachycardia, tachypnoea and reduced urine output. Septicaemia is a painful condition with myalgia, joint aches and in some cases severe isolated limb pain. Remember they may be alert and able to talk and parents may ask you “is this meningitis”?

The Rash

The rash of meningococcal disease is a source of massive diagnostic error, especially over the telephone, so beware. The rash may be absent in cases of pure meningitis. At onset, 30% of all rashes start macular-papular and blanch. The non-blanching rash can start at any time in the course of the meningitis or septicaemia – just because there is no rash present does not mean that the child may not be very ill. Research has shown that the median time for the rash to appear from the start of the illness is about eight hours in a baby and 18 hours in teenagers. The rash can become petechial (<2mm) or purpuric (>2mm). Purpura is much more ominous as it is indicative of septicaemia and significant coagulopathy.

The parents’ description of the rash.

Parents often still think of rashes as being “measles like”. They may not understand that the dark mark on the child’s skin is a rash. This leads to problems if telephone advice is being given. The non-blanching rash can look like a scratch, pinch, bruise or even chocolate.

Parents report the rashes to be red, brown, black, purple and dark pink. Ask very carefully about all marks on the body and do not readily accept parents explanations for the appearance of new ‘scratches or marks’.

Differential diagnosis

The main differential diagnosis is between a child with a self-limiting viral illness and a child with a serious bacterial infection – meningitis and septicaemia. This is a very difficult area, fraught with diagnostic challenge.

All GPs should be aware of the NICE guidelines on the management of febrile illness in children under five years. It has a lot of very useful information to aid with diagnosis of serious bacterial infection. Research has shown that a GP’s gut instinct about a case is the most useful predictor of serious illness if a child is unwell.¹ Listening carefully to parents concerns is always very important. When assessing a child’s neurological status, the key is to ask the parents about the level of functioning, as it is very difficult to assess the neurology of small children. To assess for sepsis measure the heart rate, respiratory rate and peripheral perfusion.

Investigations

In the acute setting, the only real investigation a GP can do is a thorough examination and measuring the vital signs.

Referral

All children with suspected meningitis or meningococcal disease should be referred by emergency ambulance to hospital. Children with a non-blanching rash should be given an injection of intramuscular penicillin into a warm limb prior to transfer. Febrile children who look unwell with tachycardia and delayed capillary refill time should also be referred for further assessment.

Dr Nelly Ninis is a consultant paediatrician at St Mary’s Hospital, London.

References

1. Thompson MJ, Ninis N, Perera R et al. (2006) Clinical recognition of meningococcal disease in children and adolescents. Lancet, 367 (9508); 397-403

Further reading

Meningitis Research Foundation – resources for health professionals