While many types of primary immunodeficiency (PID) have been identified, the main types cause similar symptoms in those affected. Notably these symptoms are:

  • frequent
  • repeated bouts of infections that can be long-lasting and severe.

However, it is now recognised that PIDs may present in other ways, including in people who may have non-infectious complications such as autoimmunity, inflammatory disorders with fevers, swollen joints, rashes and bowel problems, angioedema or sometimes even cancers, particularly lymphomas.

Another useful tool is called SPUR. Here PIDs should be suspected by families and doctors in people who have Severe, Persistent, Unusual, Recurrent infections and with a history of PID Running in the family (SPUR).

The ten warning signs of a PID (originally courtesy of the Jeffery Modell Foundation)

The major indicators are:

  • Failure of a baby or child to gain weight or grow normally (failure to thrive) – there are many reasons for failing to thrive and PIDs are a rare but important cause
  • The need for intravenous (IV) antibiotics to treat infections – the use of IV antibiotics indicates a serious infection and infants, children and adults should be considered for PID
  • A history of a PID in the family – family members should at least have a primary screen (full blood count and serum immunoglobulins)
  • Four or more new ear infections within one year
  • Two or more new sinus infections within one year
  • Two or more months on at least two antibiotics at a stretch with little effect
  • Two or more pneumonias within three years
  • Having frequent deep skin or organ abscesses
  • Persistent thrush or fungal infection (more than six months) on the skin or elsewhere
  • Two or more deep-seated infections, including septicaemia (blood poisioning), within three years.

Two or more of these warning signs could indicate the presence of an underlying PID. If you or your child have any of these symptoms, it’s important to talk with your doctor. He or she might refer you to a specialist, such as an immunologist.

The majority of PIDs in children are picked up by paediatricians and it is estimated that three specific warning signs would identify about 90 per cent of PIDs. These are:

  • family history
  • a requirement for IV antibiotics in the management of infections
  • failure to thrive.