Two weeks ago I saw a 20 year-old young man complaining of “allergies.” His mother accompanied him to the appointment to fill in the history of his hazy pre-adolescent and teenage years as well as to relate the recent testing results. A friend of the family had seen me in the past, had done very well on allergy shots, and had recommended me for a second opinion. For years my new 20-year-old patient would become sick at the change of seasons. His family doctor would prescribe an antibiotic, which usually helped somewhat. The young man described severe nasal congestion with thick purulent nasal secretions that could be blown into the tissue and would often drain into his throat causing a harsh cough and laryngitis. Usually he needed to get a second- or third-course of antibiotics to finally get better. His doctors tried various allergy medications to help, but he felt only the Sudafed or Afrin was actually doing anything for him. Also, about once a year bronchitis would accompany his sinus infection.
A chest x-ray had been normal. A sinus CT scan had showed some mild thickening of the sinus membranes but no surgically treatable abnormalities. He had seen an ENT surgeon following the CT scan and had some unusual allergy testing that involved a series of 150-200 injection tests. The tests were read as positive for multiple allergens, and he had been offered allergy drops or shots afterwards; however, his mother decided to get another opinion after hearing from the family friend.
His family history was notable for rhinitis and sinusitis in both parents. His younger sibling was unaffected. He did not have any other history of infection problems like pneumonia, skin infections, or meningitis. His exam was fairly normal since he had just finished 21 days of a strong antibiotic. We decided to skin test him using proper prick test technique to see if allergies were indeed contributing to his difficulties. He was not allergic to any of the types of dust, dander, pollen, or mold spores that we tested, which was a relief to him since that meant no allergy shots. We also did a pulmonary function test with results showing normal for his height and age.
Next, we ordered a complete blood count, immunoglobulin levels, and a test of complement level and function called a CH50. The results came back a couple of days later. All the tests were normal except for a very low IgA level. His level was undetectable (< 5 mg/dl). We repeated it and confirmed the result. He had IgA deficiency, not allergies.
Specific IgA deficiency (SIgAD) is the most common immune deficiency in the adult population. It is estimated that more than 250,000 people in the United States have this condition. In the general population this number works out to be about 1 in 500 people. However, in allergic populations, the risk rises to 1:100 people.
Since IgA moves from the bloodstream into the mucous, the infections that deficient people have are for the most part mucosal-based infections. The nose, throat, bronchioles, and GI tract all have increased risk of infection for people with SIgAD. The risk of having this condition is transmitted genetically but can skip generations. Some medications and some infections can trigger a temporary IgA deficient state, so rechecking levels is recommended before making a permanent diagnosis.
Having very low IgA can also increase the risk of an allergic reaction to a blood transfusion. For that reason I urge my patients with SIgAD to have a medic alert bracelet or a note in their wallet, which would alert ER docs or trauma surgeons to the condition so that proper screening can be done in an emergency.
SIgAD has no treatment. If a SIgAD patient also has allergies, we do treat the allergies in order to help with nasal/sinus or chest symptoms. If significant swelling has occurred, surgical procedures to open the sinuses or to ventilate the eardrums can help, too. Proper nutrition and exercise are encouraged to promote general health. Prompt treatment of bacterial infections of the sinuses, ears, chest, or intestines is helpful; however, overuse of antibiotics could have other effects, including development of medication allergies or antibiotic resistance.
My patient had pure Selective IgA Deficiency and thus needed no treatment for allergies. Seeing an Allergy Immunology trained doctor turned out to be extremely helpful since we provided him with answers for his condition. There is no substitute to being properly diagnosed.
Unfortunately, in this case, I had no specific treatment that could restore him to normal. He was introduced to saline nasal washes (distilled water only), encouraged in his overall health practices, and told to call when getting sick to be screened for antibiotic need. No surgery was indicated at this point in his life.