Tag Archives: allergen

Contact Allergen of the Year: Acrylates

Courtesy of Hehkuviini, via Creative Commons Attribution-Share Alike 3.0

I’ll spare you the suspense.  This year’s contact allergen of the year is the acrylates.  Yes, you probably do use acrylates.  Have artifical nails? Had dental work? A joint replacement? Plexiglas? That’s why the acrylates were chosen this year.

“We chose them because acrylates are everywhere in the environment,” said Dr. Donald V. Belsito, who announced this year’s winner at the annual meeting of the American Contact Dermatitis Society.  Acrylates are plastic materials that are formed by the polymerization of monomers derived from acrylic or methacrylic acid. While monomers are very strong irritants and allergens, fully polymerized acrylates are relatively inert.

However, “patch testing is tricky, and I think that’s something that we’re just finding out about the acrylates,” said Dr. Belsito, a professor of clinical dermatology at Columbia University in New York. “They’re very volatile. The stability of the [patch test] allergens is a major issue, and they should be frozen or refrigerated.”

Kerri Wachter (on twitter @knwachter)

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Filed under Allergy and Immunology, Dermatology, IMNG, Uncategorized

Allergen of the Year for 2010 Announced

from the American Contact Dermatitis Society annual meeting, Miami Beach

Drum roll please … the American Contact Dermatitis Society has named the antibiotic neomycin as Allergen of the Year for 2010.

Courtesy flickr user project 365 under common license

“It’s a very common allergen and raises a number of issues when someone patch tests positive to it. We thought it is something the general public and dermatologists should be aware of,” said Dr. Donald Belsito, a dermatologist in private practice in Shawnee, Kans., when making the announcement.

A positive patch test can take 7 days or more to develop, so have patients return or counsel them on what to look for, Dr. Belsito said.

He noted that there are a couple things to keep in mind when making the diagnosis of neomycin allergy.

First, many vaccines contain neomycin as a preservative. The risk to benefit considerations need to include the likely worst-case scenario–an eczematous rash–if a sensitive patient receives a vaccine containing neomycin. Contrast that with the likely worst-case scenario–contraction of a potentially lethal disease–if the sensitive patient avoids vaccination. Discuss. And don’t forget to bring the patient’s primary care doctor into the conversation, Dr. Belsito counseled.

Second, neomycin-sensitive patients can have cross reactivities to other aminoglycocides. Think kanamycin, tobramycin and others, said Dr. Belsito, who had no relevant financial disclosures.

Neomycin is more of a household name than last year’s Allergen of the Year, mixed dialkyl thioureas. My colleague Bruce Jancin described last year’s winner and patients’ reactions to it in a blog post one year ago.

—Damian McNamara (@MedReporter on Twitter)
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Filed under Allergy and Immunology, Dermatology, Drug And Device Safety, Family Medicine, IMNG, Infectious Diseases, Primary care, The Mole

And the Allergen of the Year Is … What?

From the annual meeting of the American Academy of Dermatology

The American Contact Dermatitis Society has selected as its Allergen of the Year for 2009 — drumroll, please — mixed dialkyl thioureas!


By flickr user SigmaEye, used under creative commons license

By flickr user SigmaEye, used under creative commons license

The Allergen of the Year Award has been used in the past by the society as an opportunity to increase physician and public awareness of the most common offending allergens, including nickel (2008), fragrance (2007), corticosteroids (2005), or allergens trending upward in importance, such as cocamidopropylbetaine, a surfactant contained in a dizzying array of personal care products.

But mixed dialkyl thioureas isn’t a top-10 allergen. In fact, it’s the 50th most common allergen to be positive on patch testing, a spot it has solidly held down for the last 15 years. It accounted for about 1% of all positive patch tests in a large study by the North American Contact Dermatitis Group.

“I can imagine what you’re all thinking,” Dr. David E. Cohen quipped in breaking the news regarding the newly crowned 2009 Allergen of the Year to a crowd of perhaps 600 dermatologists. “One of you may be saying, ‘Finally!’ The rest of you are probably thinking what I’m thinking: Has the committee been drug tested?”

Actually, the selection committee probably chose mixed dialkyl thioureas because this set of two chemicals is commonly encountered in a wide range of daily activities. Mixed dialkyl thioureas are employed in the vulcanization of rubber, especially neoprene. They’re found in gloves, hip waders, athletic shoes, adhesives, pesticides, computer keyboard wrist rests, swim goggles, orthopedic prostheses, sleep apnea masks, coated copy paper, elastic in clothing, and a bunch of other stuff.

Testing with the better-known rubber allergens, including carbamates, thiurams, and mercaptobenzothiazole, often fails to detect mixed dialkyl thiourea-induced allergic contact dermatitis.

“If you suspect allergy to rubber, patch test appropriately, and come up with a negative result, consider mixed dialkyl thioureas,” urged Dr. Cohen, vice-chair of the department of dermatology at New York University.

—Bruce Jancin

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Filed under Allergy and Immunology, Dermatology, Uncategorized