Contact Dermatitis 2014: Diagnosis and Management Strategies

Mathew J. Zirwas, MD

 

In this presentation, Dr Zirwas, an Associate Professor of Dermatology at Ohio State University and an expert in contact dermatitis, makes understanding contact dermatitis “easy” for the practicing dermatologist…

Dr Zirwas begins the presentation by reviewing some of the new allergens on the T.R.U.E. Test and what we need to know about them…

Steroid Allergies

Tixocortol Pivalate, budesonide, and hydrocortisone butyrate are all markers for allergy to steroid. There is a simplified way to approach the management of this allergy. We know that there are cross-reactor groups A, B, C, D1, D2…in a steroid allergic patient you can either figure out which class they are allergic to, then pick a steroid in a different class (which could still cross-react!) or you can simply use of the two topical steroids that do not cross react with other steroids. These are clocortolone and desoximetasone. These are class C steroids and do not cross-react with anything else.  Also keep in mind that about ten percent of people who react to tixocortol pivalate will have allergy to prednisone if it is given systemically. This is very similar to the way that we think about cephalosporins with penicillin. When someone is allergic to penicillin, we say that there is about a ten to 20 percent chance that they will have a reaction to cephalosporins. This is the same thing, when someone is allergic to tixocortol pivalate, there is about a ten percent chance that they will be allergic to prednisone…they will clear on 40mg, usually stay clear on 20mg and break out in a drug rash around 10mg because the pharmacologic effect of the prednisone is now being outweighed by the allergy to the prednisone.

What if someone is allergic to Diazolidinyl Urea, Imidazolidinyl Urea, 2-Bromo-2-nitropropane-1, 3-diol?

For these patients, treat them as if they are formaldehyde allergic. They may be allergic to only one or two formaldehyde-releasing preservatives, but 90 percent plus are formaldehyde allergic and need to avoid all the formaldehyde related substances. It is a little bit more of a conservative approach, but it’s the approach that experts in contact dermatitis use.

What if a patient comes in stating that she is allergic to titanium dioxide?

Remember that allergy to titanium dioxide is extremely uncommon. This patient may be allergic to gold sodium thiosulfate. How is gold related to titanium? Gold is related to titanium dioxide because gold, itself, is very inert; however, it interacts with titanium dioxide, which is in most make-ups and sunscreens. The problem is that it interacts with the gold jewelry that women wear; therefore, they may break out in a rash where they apply their make-up/sunscreen. These patients need to either stop wearing make-up and sunscreen OR replace their gold jewelry with platinum, which is the best replacement for gold. Patch test reactions to gold can persist for three to six months. If they persist, Dr Zirwas will inject 0.1-0.5ml of TAC-5.

What about a patient who comes in with a facial rash every spring?

A patch test may determine that this patient is allergic to parthenolide. Parthenolide is a marker for an allergy to the Compositae family of plants. There are around 20,000 plants in this group but as dermatologists we only need to remember a few key points about this group. The first of which is to avoid Aquaphor. Aquaphor has bisabolo in it, an extract of German Chamomile, which is in this group. In general, Dr Zirwas tells parthenolide allergic patients to avoid anything that has to do with a botanical.  This is a conservative approach; however, it is much more effective than determining to which of the 20,000 plants a patient may be allergic.  Some patients can get airborne contact dermatitis from pollens that have SQLs on the surface, especially ragweed and goldenrod. These can be difficult patients; they either need to move somewhere with less pollen, or they should be immunosuppressed during the months of the year when they tend to get this allergy.

Allergies to Dyes

There are thousands of different dyes that are used to dye clothing. Disperse Blue 106/124, while not great for ruling out textile dye allergy, is the best screening agent we’ve got.  Remember that you cannot tell what dye was used based upon the color of the clothing. If a patient is positive, then synthetic textiles of all colors become suspect. These allergic reactions tend to be acute and intermittent. Usually, specific items of clothing can be identified, such as exercise clothing and liners in dress clothing. Normally, once you tell the patient what to look for, they can tell which items of clothing are causing the reaction.

Other T.R.U.E. Test Allergens

  • Quinoline Mix
    • Rarely relevant- Bag Balm, some others
  • Mercaptobenzothiazole
    • No different than other rubber accelerators
  • Bacitracin
    • Need to avoid polysporin, etc.

 

T.R.U.E. Test Conclusions

The T.R.U.E. Test is better than it used to be; however, it is still not that good for certain things. It is good for identifying allergies to metal, rubber gloves, and topical antibacterials. It is NOT good for personal care products, make-up, topical steroids, and other interesting things such as acrylic nails, prosthetic joints, sports equipment, etc.

The T.R.U.E. Test is best for ruling IN a diagnosis of rubber glove allergy, neosporin/polysporin allergy, and metal allergy. Its WORSE uses are in ruling out contact dermatitis when you’re unsure of the etiology.

What are the chances that a patient will get better with the T.R.U.E. test?

Considering patients who aren’t allergic to metal, rubber, or polysporin, it’s actually about one percent. How does Dr Zirwas get this number? Well, when you look at a patient and think it might be contact dermatitis, but aren’t sure to what, the chances are that it is contact dermatitis in about 20 percent. The probability of an accurate diagnosis with the T.R.U.E. test is about 20 percent. The probability that a patient will remember what they are allergic to is about 50 percent, at best.  The probability that the patient will avoid the allergen, if they remember it, is 50 percent, at best. Therefore, 20% x 30% x 50% x 50% = 1% (at best).

What else can we do?

The American Contact Dermatitis Society publishes a list of allergens and a screening panel, which is an excellent resource for people who want to implement comprehensive patch testing.  But what do you need at a minimum? You need to buy ten tubes of allergen and one box of Finn® chambers. This will cost about $400.00

Supplement the T.R.U.E. Test with following 10 allergens:

  • Methylisothiazolinone 2000 ppm
  • Formaldehyde 2%
  • Propylene Glycol 100%
  • Fragrance Mix II
  • Cocamidopropyl Betaine
  • Amidoamine
  • Dimethylaminopropylamine
  • Hydroxyethyl Methacrylate
  • Ethyl Ethacrylate
  • Propolis

Additionally, The American Contact Dermatitis Society has a database, CAMP. This is very user-friendly, i.e., you check the boxes with regards to what the patient is allergic and it, in return, provides you with a list of safe products for that specific patient. This way, your patients do not have to read labels and figure out what to avoid, you can simply provide them with a list of products that they CAN use.

Mypatchlink.com is another resource containing a series of free-access videos that review all of the remotely common allergens. There are also handouts that go along with the videos and they are extremely useful.

Methylisothiazolinone 2000 is an enormous epidemic. This is probably due to a combination of reasons; firstly, there is increased exposure because of the move away from parabens and formaldehyde-based preservatives. Second, until recently, we have been patch testing with too low a concentration and as a result, for the last 10-15 years, we have probably been missing a lot of the people who are allergic to this. Remember the 3 Fs—Faces, Fannies and Fingers. Methylisothiazolinone is often found in shampoos, conditioners, facial soaps, moist toilet paper, hand soaps, and baby wipes.

Formaldehyde is still a very common allergen. One percent formaldehyde, which is the standard allergen, misses a lot of cases; therefore, we have gone to testing formaldehyde two percent.  You get a few more irritant reactions, but pick up a lot more cases of true allergy.

Propylene glycol is now tested at 100 percent. You do not get irritant reactions, but you do pick up a lot more reactions than when we used to test with 30 percent. Propylene glycol is in most topical steroids and NEEDS to be ruled out as a cause of chronic dermatitis.

Fragrance Mix 2 is no different in terms of clinical manifestations compared to the original Fragrance Mix, but these are newer fragrances that are more relevant and pertinent. If you are only testing with FM1 and Balsam of Peru, then you are probably missing 30 percent of fragrance allergy patients.

Cocamidopropyl betaine, amidoamine, and dimethylaminopropylamine are three different ways to test for allergy to modern lathering/foaming agents. Lathering agents are a very common cause of facial dermatitis from shampoos, facial cleansers, and conditioners. Keep in mind that while conditioners do not lather, there is a related ingredient called stearamidopropyl dimethylamine that is chemically related.

Hydroxyethyl methacrylate and ethyl acrylate are the best markers for acrylate allergy, a common cause of allergy from nail cosmetics. This is a much more common problem than nail polish allergy and these patients MUST avoid all types of artificial nails (acrylic, gel, solar, wraps, tips, etc..) This allergy also indicates a need to avoid bone cement in prosthetic joints.  If a patient is allergic to acrylates, this is a much bigger problem than if they were allergic to nickel and they receive a metal implant.  There is a lot of controversy around whether or not a metal implant will be problematic for patients who are allergic to nickel, but general agreement that acrylate allergic patients will have a problem if bone cement is used when putting in a prosthetic joint.

Propolis is the last of the ten allergens that Dr Zirwas would use in addition to the T.R.U.E. Test. Propolis is related to beeswax and is found in a lot more products than you would think, it is especially a problem in some lip products.

If a patient presents with widespread dermatitis, but not on the face, they may be allergic to potassium peroxymonosulfate, the active ingredient in shock treatment for hot tubs (and pools).  Dr Zirwas sees this mostly in male patients. Why? Because men are the ones who are taking care of the hot tub/pool, adding the treatment and are subsequently exposed to high concentrations while scooping it out of the container, leading to sensitization.  Then, when they get in, they break out in a widespread rash.  If a patient has widespread dermatitis, he/she should stay out of their hot tub. If they get better, they should change the shock treatment to H202 or hypercholorination.

If a patient has papules on extensor elbows, you should consider dietary nickel as a possible cause – this is a much more common cause of itching papules on the elbows than is dermatitis herpetiformis.  He/she should consider a low nickel diet consisting of oatmeal, legumes, canned goods, dark chocolate, stainless steel pots/pans, and should only drink bottled or distilled water. Patients should also take vitamin C with every meal.

Summary

Contact dermatitis can be a challenge for the practicing dermatologist. Keep in mind that the T.R.U.E. Test is best for ruling IN a diagnosis of rubber glove allergy, neosporin/polysporin allergy, and metal allergy. Its WORSE uses are in ruling out contact dermatitis when you’re unsure of the etiology.  Remember to supplement the T.R.U.E. Test with the ten allergens previously discussed.

 

MauiDerm News Editor- Judy Seraphine