AAAAI - Patients & Consumers Center: Allergy & Asthma Advocate: Fall 2006

Infections, particularly viral infections, are common throughout childhood into adulthood. Any parent with a child in daycare or school anticipates colds, ear infections and diarrheal illnesses during the year. In patients with allergies, sinus infections can be frequent. Some people feel they are always at the doctor’s office for yet another infection or an infection that just won’t go away. So, when are these infections so frequent that your doctor should suspect an immune deficiency?

A child less than two years old may normally have six to eight colds a year, with similar numbers for ear infections and vomiting/diarrheal illnesses. At the extreme end, a child with a normal immune system may have up to twelve of these infections a year. Factors that increase the frequency of infections include daycare attendance, exposure to cigarette smoke, allergies and malnutrition. Although children with normal immune systems have colds and ear infections, those with an immune problem have multiple, serious, difficult to treat, or unusual infections.

An immune deficiency is due to defects in the body’s ability to fight infections. Immune deficiencies may be primary or secondary. Primary means that there is an inherited problem with the immune system. Frequently, these are diagnosed in infancy or childhood. Because primary immune deficiencies are inherited, it is important to know whether other family members have problems with infections or have an already diagnosed disease. Secondary means that someone has another disease, such as cancer or infection including HIV, which causes the immune system to fail. Immune deficiencies, whether they are primary or secondary, often present in similar ways.

The most common manifestation of an immune problem is decreased resistance to infections. This means that repeated infections occur, or they are more severe and cause unexpected complications. For example, respiratory infections tend to occur more frequently. Those with more than eight ear infections, two serious sinus infections, or two episodes of pneumonia per year should be investigated for an immune deficiency. Another type of infection that can be more frequent is thrush. This is a yeast infection in the mouth that is common in normal infants. If thrush is persistent after 1 year of age, there may be an immune problem.

Serious infections are ones that affect bone, joint, brain, blood and liver. Deep skin boils can also be a symptom of an immune problem. These usually require intravenous antibiotics and hospitalization. Recurrence of these, lack of improvement with treatment, or the infection progressing may indicate an immune defect. Infections in the gut also occur frequently in those with an immune deficiency and cause problems with food and nutrition absorption and even disease of the liver. These can lead to chronic diarrhea and vomiting. Often the frequency of infections – serious or not – and constant losses in the gut can lead to poor weight gain and slow development in a child.

Occasionally, it is not the frequency of infection that leads to an immune deficiency diagnosis, but the type of infection itself. Some bacteria and fungi are normally found within humans, but when there is a problem with the immune system, these microbes can infect the body. These characteristic infections are called opportunistic infections. Sometimes, an infection that normally causes mild disease will cause severe problems if the immune system cannot target it. For example, children who are infected with chicken pox or infectious mononucleosis generally have a mild illness that resolves without problems. In those with an immune defect, these viruses can be fatal.

Immune deficiencies are not common, but they can be serious. It is important to recognize when infections are suspicious so that your physician can order the appropriate tests. The circumstances that are concerning include having someone in the family with an immune problem; more than the usual number of infections; and serious or unusual infections.

10 Warning Signs of Primary Immunodeficiency

Eight or more new ear infections within a year.
Two or more serious sinus infections within a year.
Two or more months on antibiotics with little effect.
Two or more pneumonias within a year.
Failure of an infant to gain weight or grow normally.
Recurrent deep abscesses in the skin or organs.
Persistent thrush in mouth or on skin, after age one.
Need for intravenous antibiotics to clear infections.
Two or more deep-seated infections such as meningitis (brain), osteomyelitis (bone), cellulitis (skin), or sepsis (blood).
A family history of primary immunodeficiency.

*Courtesy of The Jeffrey Modell Foundation

Allergy & Asthma Advocate: Fall 2006

When are infections too frequent?