Annual Bluegrass (Poa annua)

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Kentucky bluegrass is the most common turfgrass in the United States. Its use as a turf grass in Arizona is limited to the cooler parts of the state, typically at elevations about 5000 ft, although it may be used in some aggressively maintained golf courses at lower elevation. Annual bluegrass is a weedy variety that invades Bermuda grass lawns and fields in Arizona desert communities during the fall through spring. Birds and small animals eat the seed of the grass providing widespread distribution. Bluegrass pollen is highly allergenic and cross reacts with other cool weather grasses such as Rye grass and Timothy grass. It likes cool, wet conditions and will proliferate and take over lawns and sport fields if we have a rainy winter.

Sulfa

Sulfa Antibiotic Allergy: Common and Frequently Misunderstood

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Sulfa drugs were the first antibiotics

Sulfa drugs were the first chemicals available to treat bacterial infections in humans.  The proper designation for this class of drugs is sulfonamide but they became knows as “sulfa” antibiotics with their widespread use as powders and pills during WW ll.  Although sulfa antibiotics saved lives, their use decreased significantly after the introduction of penicillin because of frequent adverse reactions and emerging bacterial resistance.

Seven Percent of Patients Taking Sulfa Antibiotics Have Adverse Reactions

Approximately 6-8% of patients who take these drugs have adverse skin reactions ranging from a measles-like rash,  hives and swelling, to severe life-threatening skin blistering conditions such as Stevens-Johnson syndrome and toxic epidermal necrolysis.  In HIV- infected patients, the adverse reaction rate to sulfonamide antibiotics is as high as 25 to 50 percent!

For a number of years, the drugs Bactrim DS and Septra DS (which contain two antibiotics: trimethoprim and sulfamethoxazole) were used to treat ear infections in children.  Sulfamethoxazole is a sulfonamide antibiotic.  If patients developed a rash while taking these drugs, they were told that they were allergic to sulfa and should avoid all sulfa drugs in the future.  These antibiotics were widely prescribed and so the number of adults now reporting a history of sulfa allergy is significant.

Sulfa vs Sulfur vs Sulfite vs Sulfate vs…..

As mentioned, “sulfa” is a colloquial designation for sulfonamide antibiotic, but the prefix “sulf” is found in an enormous number of other medications that may contain sulfur, sulfites or bisulfate including penicillin antibiotics, reflux medications, pain medications, blood pressure medications, and a variety of supplements. For example ferrous sulfate is a common medication used to treat iron deficiency.  The chemical structure for the popular diuretic Lasix (furosemide) contains sulfur.   Neither of these medications cross react with sulfonamide antibiotics.

The use of trimethoprim/sulfamethoxazole to ear infections in children has decreased significantly because of an increase in bacterial resistance to these antibiotics.  However, this and other sulfonamide antibiotics are still frequently used to to treat urinary track infections and skin infections with MRSA.

Medications to avoid if you are allergic to sulfa antibiotics

Patients who have had adverse reactions to sulfonamide antibiotics should avoid all sulfonamide antimicrobials including:

  • Sulfamethoxazole, cotrimoxazole
  • Sulfasalazine
  • Sodium sufacetamide
  • Silver sulfadiazine

Other drugs that should be avoided include:

  • Dapsone
  • Darunavir
  • Fosamprenavir
  • Trimethoprim

Drugs that you do not need to avoid if you are allergic to sulfa

Drug class
Drug or compound
Comments
Sulfonamide non-antimicrobials
Alpha-blocker
Tamsulosin
Cross-reactivity is unlikely between sulfonamide antimicrobials and sulfonamide non-antimicrobials
Antiarrhythmics
Ibutilide, sotalol
Anticonvulsants
Topiramate
Carbonic anhydrase inhibitors
Acetazolamide, methazolamide, dorzolamide, brinzolamide
COX-2 inhibitors
Celecoxib
Diuretics, loop
Furosemide, bumetanide
Sulfonylureas
Glimepiride, glyburide, gliclazide
Diuretics, thiazide
Hydrochlorothiazide, chlorthalidone, indapamide, metolazone, diazoxide
Triptans
Sumatriptan, naratriptan
Other
Sulfur
No sulfonamide moiety and therefore no cross-reactivity
Sulfate (eg, ferrous sulfate, magnesium sulfate)
Sulfites (eg, sodium metabisulfite)

Source:  https://doi.org/10.1016/j.jaip.2019.05.034

A New (?) Treatment for Peanut Allergy

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New Product to Treat Peanut Allergy

The Allergenic Products Advisory Committee of the Food and Drug Administration (FDA) recently voted to recommend approval of a new treatment for peanut allergy to the FDA.  The treatment was previously referred to as AR101 but it is expected to go by the brand name Palforzia,  If as expected,  the FDA gives the go ahead, it will be the first treatment for food allergy approved by the FDA.

A few important points about Palforzia

  1. It is not a medicine.

Palforzia is a capsule filled with a precise amount of peanut powder.  Thats it.

2. Palforzia is a form of oral immunotherapy

Oral immunotherapy is a process of feeding an allergic individual an increasing amount of the food they are allergic to with the goal of increasing the threshold that triggers a reaction. Immunotherapy for airborne allergens such as pollen, mold, and animal dander has been available by subcutaneous injection (allergy shots) for many years and is an effective treatment for seasonal allergies, allergy to pet dander, asthma, and eczema.  Recently, a sublingual (under the tonge) immunotherapy tablet has been approved by the FDA for the treatment of grass and ragweed pollen allergy.  Unfortunately, the grass tablet does not contain Bermuda grass and so is of limited value in Phoenix and other desert communities in Arizona.  This will be the first oral form of immunotherapy to be approved for the treatment of a food allergy.

3. It is not a cure

By increasing the threshold dose of food required to cause a reaction, it is hoped that treatment with Paforzia will decrease the risk of a  life threatening allergic reaction in the event that peanut is eaten by mistake.   It will not allow peanut allergic patients to enjoy a Snickers bar or PBJ sandwich.  With this treatment,  a child who was at risk of a trip to the hospital if he ate half of a peanut,  may be able to tolerate 3-4 peanuts before a severe reaction occurs.

4. It is for life

Patients must take the peanut capsule every day… forever!

5. There are risks

Patients receiving treatment with Paforzia  frequently have allergic reactions to the peanut powder. These reactions range from a stomach ache to anaphylaxis.   For this reason patients on Paforzia must carry self injectable epinephrine at all times.

Weighing the Risks versus Benefits

The challenge for doctors, patients and parents considering this new treatment will be in evaluating the  benefits versus the risks: Does the benefit of having some protection against a life-threatening reaction to an unexpected exposure to peanut outweigh the risk of frequent allergic reactions with the daily treatment?