Tag Archive for 'allergy'

The Allergies That Weren’t

Published on January 18, 2012 in Immune System. 1 Comment Tags: , , , , , , , , , , .

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.

The SLIT-uation.

Published on February 11, 2011 in Allergies, FDA, Immunotherapy and SLIT. 0 Comments Tags: , , , , , , , , , , , , , , , , , , , , , .

One of my patients with a significant history of allergies who had been repeatedly late for her weekly allergy shot asked me the other day in clinic whether we also offered sublingual immunotherapy or SLIT, the liquid allergy drops patients place under their tongue and then swallow. More and more allergy and ENT practices are making this alternate form of allergy immunotherapy available. Unfortunately, the FDA has not yet approved SLIT for use in the United States, although this method of allergy desensitization is commonly being used in Europe. Some doctors in the United States have been using the same allergy extract regularly approved for injections for sublingual treatments, although the doses administered sublingually are much higher.

And here lies the rub. Current studies on SLIT, most done in Europe, don’t delineate the precise, effective dose necessary for treatment success. In the U.S., such doses are regularly agreed upon for our much more commonly prescribed allergy shots. Further, most SLIT studies in Europe focus on patients who are mono-sensitized or allergic to only one allergen. Here in the U.S., patients are largely multi-sensitized or allergic to multiple different allergens. Most of our allergy shot patients are therefore prescribed allergy extract that consists of many different allergens, such as cat, dog, dust mite, tree, grass, mold and weed—not just grass extract alone, for example. We’re not sure yet whether mixing many different allergens together for SLIT would be as effective in treating multi-sensitized patients as one sublingual extract is in treating patients only allergic to one allergen. The one SLIT study done so far in the United States that looked at treating patients with multiple allergies revealed that mixing the allergens together blunted their efficacy.

Nonetheless, SLIT will likely become a commonly prescribed allergy treatment in the future. Like allergy shots, SLIT has been shown to be effective for treating allergic asthma and nasal and ocular allergies. Unlike allergy shots, SLIT can be administered at home and has a low risk for anaphylaxis, although serious allergic reactions have occurred. Recent evidence has even shown that both shots and sublingual drops might also help treat allergic patients with eczema or atopic dermatitis. As with allergy shots, SLIT has been shown to have long-lasting benefits, remaining effective years after patients have stopped the drops. Again, these promising results apply to mono-sensitized patients treated with allergic extract containing only one type of allergen and not necessarily to the multi-sensitized patient who predominates in the U.S.

Future SLIT studies will hopefully reveal how doctors can appropriately dose and mix relevant allergens to achieve the best treatment outcomes. Until that information is known, patients should understand that SLIT for patients with multiple allergies is in an investigational stage. Because SLIT is not FDA-approved it is not currently covered by insurance. Therefore doctors who provide this therapy do so off-label and so often charge cash. For all these reasons, the Atlanta Allergy & Asthma Clinic does not yet offer SLIT. As more information becomes available we may change our views, but for now, we prefer the tried and true.

What Can You Do About Your Penicillin Allergy?

Published on January 16, 2011 in Uncategorized. 3 Comments Tags: , , , , , , .

We have so many different oral antibiotics available today, who cares if you are penicillin allergic? To treat your next sinus or ear infection your doctor can instead prescribe clarithromycin (Biaxin) or levofloxacin (Levaquin) or azithromycin (Zpak) or doxycycline or even cefdinir (Omnicef), a cousin of penicillin. For the most part, these alternative antibiotics work well and often suffice. Unfortunately, using them, especially the broader spectrum drugs like Levaquin, a member of the quinolone family of antibiotics, may actually increase your chances of developing a future infection with harder-to-treat, penicillin-resistant, bacteria. Doctors prefer to keep the big guns, the broadest spectrum antibiotics, in their holsters for just such situations. But if the big guns are used up-front and over and over again for common infections, chances are you will ultimately develop a resistant bug hopefully susceptible to an IV antibiotic, which may require you to be hospitalized for treatment. Such situations can be life-threatening.

Penicillin allergy also increases your risk of being allergic to another, related group of antibiotics, the cephalosporins. To further confuse the issue, these cephalosporin antibiotics are divided further into different “generations”: first, second, third, and now even a fourth. Allergists generally believe that patients with penicillin allergy will be more likely to be allergic to first generation cephalosporins like cephalexin (Keflex) because the two drugs share similar chemical structures. We think penicillin allergic patients are less likely to be allergic to third generation cephalosporins like cefdinir (mentioned above) as the chemical structure of the two drugs differ more. Truly penicillin allergic patients are thought to be allergic to all cephalosporins about 2-8% of the time, but those unfortunate and rare patients with the allergy to both can experience life-threatening reactions. So while many primary care doctors still prescribe Omnicef to patients with a history of penicillin allergy, they do so uncomfortably. Some doctors won’t test the waters, leaving you with fewer antibiotic options.

A few allergists joined forces with allergy extract maker ALK to help patients avoid the above scenarios by reintroducing the key component to penicillin skin testing that had been taken off the market in 2004. Pre-Pen, the major breakdown product of penicillin and the key to accurate penicillin skin testing is back. Now allergists across the country can better assess whether their patients are truly allergic to penicillin. This testing proves especially useful given most patients who think they are allergic, in fact, aren’t. Of all patients who say they are allergic only 10% actually are. Even those patients who truly once were allergic, lose their allergy over time—as many as 80% of patients lose their allergy after 10 years.

Without skin testing, even allergy experts have a difficult time figuring out whether you ever were or still might be allergic to penicillin. Skin testing assesses for the presence of penicillin-specific immunoglobulin E or IgE, the type of antibody also responsible for allergies to peanuts, tree pollen, dog dander, mold . . . . etc. An IgE-mediated allergic reaction to penicillin might cause symptoms of hives, itching, throat closing, wheezing, shortness of breath, light-headedness, nausea, etc . . .all of which are characteristic of severe allergic reactions or anaphylaxis. These symptoms generally appear within minutes to 2 hours after ingestion and usually occur after a patient has been previously exposed to penicillin. Unfortunately, patients don’t always remember in detail their allergic symptoms, especially when their reaction occurred years ago or as a child.

Patients may develop other types of rashes after penicillin ingestion which clouds the clinical picture even more. These other rashes are not usually life-threatening and not usually associated with development of the IgE antibody. For instance, patients may develop a red, rough, bumpy rash after penicillin ingestion which is often termed “maculopapular” by health professionals. These rashes are common in children taking penicillin and may occur even 7-10 days after completing the penicillin treatment course. In patients who develop these delayed rashes to penicillin, only 10-13% will actually develop another rash if re-exposed to the drug. In some cases, a viral infection, often mistaken by our medical community as bacterial and thus treated with antibiotics, may cause rashes by their own accord, unfairly implicating the patient’s antibiotic. It’s also been shown that some antibiotics interact with viral infections to create a rash, as occurs when patients infected with viral mononucleosis are given amoxicillin.

Other very severe, life-threatening penicillin drug reactions, such as Stevens-Johnson syndrome, are also not IgE mediated and so fail to register a positive reaction on standard skin testing. These reactions often involve a severe, diffuse rash with blistering of the mucous membranes and internal organ involvement. If these patients survive their drug allergy, they rarely have to be told to avoid all penicillin drugs in the future.

So penicillin allergy is not always straight-forward but determining whether you are currently at risk for a life-threatening penicillin reaction can be accomplished. Bottom line: if you think you are penicillin allergic you might not be. Speak to your local allergist to see if you might be a candidate for skin testing.