This is a continuation of last week’s interview with Dr Steve Xu MD MSc where we discussed contact dermatitis, the differences between irritant and contact dermatitis, the top 10 pediatric contact allergens in personal hygiene products and practical consideration of when to suspect contact dermatitis in a child.

Dr Steve Xu, MD MSc is currently a 2nd year dermatology resident at McGaw Medical Center of Northwestern University. He earned his MD from Harvard as a Soros Fellow, and a Masters in Health Policy and Finance from The London School of Economics as a Marshall Scholar. He completed a BS in bioengineering at Rice University. For his academic interests, Steve is focused on consumer education and the intersection between health policy and clinical medicine. His publications have appeared in The New England Journal of Medicine, and PLOS Medicine garnering broad press attention from sources such as CNN, The Washington Post, and The Los Angeles Times. Dr Steve has created a web resource for patients with eczema and contact dermatitis at itchyrash.org. See also Dr Steve’s publications at the end of last week’s post.

Dr Steve Xu MD, MSc

On ‘Bland’ Skincare Products

MarcieMom: I’ve emphasized in my blog that the fewer the ingredients, the less likely it is to irritate (such as in this expert interview and also in the moisturizer selection post)

Yet, practically (I’m finding myself using this word so frequently in this 2-part interview! It must be that it is so hard to take practical steps when it comes to skincare products and figuring out irritants, allergens and pushing through the myriad of chemical names!) and yes, practically it can be difficult to find a skincare product with less than 10 ingredients! Pharmaceutical companies seem to add more ingredients to their formulation in order to ‘upgrade’ their product to one that can restore your skin’s lipids, ceramides, reduce itch and bacterial infection.

MarcieMom: Is there a trend towards more ingredients in the formulation of skincare products? And is it a real risk or can consumers assume that product companies would have tested their increasingly complex formulation that it would not lead to contact dermatitis? 

Dr Steve Xu: Again, labels such as ‘hypo-allergenic’ or ‘sensitive skin’ really don’t mean anything. The Food and Drug Administration do not regulate this definition. Consumers have to be aware of this.

I wouldn’t say there’s a trend towards more ingredients in skincare products. Skincare products aren’t produced for hypo-allergenicity. These products are successful because they smell nice (fragrances), feel good on the skin, and stay fresh (preservatives). I think for individuals with patch-test proven allergic contact dermatitis, it’s really important to follow the safe list. But, if you haven’t been patch tested yet and have very sensitive skin, then looking for products with as few ingredients as possible AND do not have common skin allergens is a reasonable consideration.

Moisturizer Selection – Reducing possible contact allergens

MarcieMom: Staph bacteria has been covered in my blog, and we know that eczema skin that has staph bacteria colonization will not recover well due to inflammatory toxins from the bacteria. Are moisturizers for eczema/ dry skin incorporating antiseptic properties? Which antiseptics are now recommended for eczema children and how likely are these to irritate skin?

Dr Steve Xu: Absolutely, treating staph colonization is a big component of successfully treating atopic dermatitis. Moisturizers typically don’t have anti-bacterial ingredients. But, we do know that impaired or broken skin barrier facilitates the colonization and growth of staph. Thus, moisturizers play a big role in keeping the skin barrier intact so that staph can’t cause problems.

At least in the U.S., we hardly ever specifically recommend an ‘anti-septic’ moisturizer. It’s interesting to see that there are products out there marketed as such. We separate the use of moisturizers (barrier protection) and the elimination of colonizing bacteria (mupirocin ointment, bleach bathes). Typically for our patients, we always recommend moisturizers for skin barrier preservation but tend to be more reactive when it comes to recommending bleach bathes or mupirocin ointment at the sign of super infection (formation of pustules).

With that being said, lauric acid is certainly an ingredient that is becoming more and more popular. It is the key component in coconut oil, which has shown to have a broad range of antibacterial properties.

Long-story short, I think there’s probably a benefit from using antiseptics more regularly in managing atopic dermatitis. We know that the skin of eczema children have less anti-microbial peptides, natural bacteria fighting proteins produced by the skin. There’s no great head to head studies comparing coconut oil (moisturizer + anti-septic properties) vs. a regular moisturizer in managing atopic dermatitis. But, I think there is some benefit here that may be real for some patients that have a particular sensitivity to staph colonization.

Skin of eczema children is more susceptible to staph bacteria colonization

Also, common over-the-counter topical antibiotics such as neomycin and bacitracin are notorious agents for causing allergic contact dermatitis. We typically do not recommend these for children with atopic dermatitis. In the United States, we prefer topical mupirocin (prescription only). This medication rarely causes allergic contact dermatitis compared to neomycin or bacitracin.

Age of Allergic Contact Dermatitis

In the article¹, it was mentioned that studies have shown that there are different age (timing) where there is peak prevalence of contact allergy among children, being

1. 0 – 3 years old – could be due to immature skin barrier, including lower lipid content, fewer natural moisturizing components, higher pH and thinner epidermis
2. 6 – 7 years old
3. Adolescence

MarcieMom: Are there a certain group of children who is more likely to have contact dermatitis? Narrowing this further, is there a particular profile of eczema children who are more likely to also have contact dermatitis?

Dr Steve Xu: This is a great question. I think certainly, older children and adolescents will have had greater exposure to potential allergens over time. However, an allergic contact dermatitis can occur at any age including toddlers. I think the most important thing is to have a high index of suspicion for allergic contact dermatitis in children with atopic dermatitis.

Is your child’s atopic dermatitis not getting better despite the best therapy?

Is your child’s atopic dermatitis appearing in areas that it never appeared before?

Are there eczematous rashes that seem to happen in the same locations such as the belly button, neck, waistband or wrist? Do the rashes appear linear (straight) or rectangular?

We’ve had plenty of pediatric patients with stable atopic dermatitis that would inexplicably get worse or not respond to therapy. After patch testing, we would identify a common allergen such as nickel. The rashes won’t get better unless nickel is avoided.

Corticosteroids

In the article1, it was mentioned that the most “allergenic” corticosteroids are:

1. Budesonide
2. Trixocortal pivalate
3. Hydrocortisone butyrate

The least allergenic are those with halogenated C16-methylated molecules and in order of increasing potency:

1. Aclomethasone dipropionate
2. Beta-methasone valerate
3. Memoetasone furoate
4. Desoximethasone
5. Clobatesol propionate

Corticosteroids – Potency and Allergenicity

Again, there is the possibility of children with atopic dermatitis using more topical steroids and therefore getting hypersensitive to it overtime.

MarieMom: The article mentioned classifying topical steroid creams using different groups, based on their likelihood of being contact allergens. The likelihood can be due to different molecular (steroid) structure, the other non-steroid ingredients in the prescription cream, how long it is used and how occlusive it is (topical steroid creams are not recommended with wet wraps as absorption rates are higher than intended when occluded).

MarcieMom: What are the common steroid creams prescribed for young children with eczema? And how likely will they cause contact dermatitis?

Dr Steve Xu: Overall, a true allergic contact dermatitis to topical steroids is quite rare. Aclomethasone and desoximethasone are both popular choices.

I will say that sometimes it’s better judicious to not always reach for the least hypo-allergenic topical steroid at first. In the vast majority of time, a children will not have a contact allergy to a topical steroid. If we reach for a hypo-allergenic topical steroid and a contact allergy does develop, we have less therapeutic options in the future.

MarcieMom: Thank you Dr Steve for your time to help with this series; really glad for this interview as it has certainly raised my awareness of contact dermatitis in children (where previously thought to be remote). Also appreciate the work that you’re doing at itchyrash.org

References:

1. Hannah Hill, Alina Goldenberg, Linda Golkar, Kristyn Beck, Judith Williams & Sharon E. Jacob (2016): Pre-Emptive Avoidance Strategy (P.E.A.S.) – addressing allergic contact dermatitis in pediatric populations, Expert Review of Clinical Immunology, DOI: 10.1586/1744666X.2016.1142373

Eczema Blues

Eczema is a skin condition with many parts to the puzzle – it is linked to hereditary skin condition, allergens (food, inhaled, contact and airborne), environmental factors (heat, humidity), bacteria colonization on skin (and how gut microbiome may affect allergic conditions), lifestyle factors (stress, hormonal change) and also suspected to be linked with diet/ water. Very often we may think of what we have eaten, rather than what we have applied on our skin. A moisturizer or topical prescription tend not to fall under our usual ‘list of suspects’ when we try to figure out what’s triggering the eczema.

This 2-part blog series aim to bring greater awareness of contact allergens, and how some of these may be the ingredients in your skincare products. Especially for pediatric patients, we have to be even more careful because:

1. Babies’ skin barrier is thinner than that of an adult- making it extra vulnerable to chemical irritants (also greater transepidermal water loss and therefore, moisturizing is important)
2. Increasing research showing that a strong skin barrier has protective effect against eczema, and reduce likelihood of food sensitization
3. Babies have a larger surface area to volume ratio, therefore potentially the risk associated with chemical absorption is higher

Contact allergens is of particular importance to pediatric patients

I’m privileged to have dermatologist Steve Xu, MD MSc to help with this series. Dr Steve is currently a 2nd year dermatology resident at McGaw Medical Center of Northwestern University. He earned his MD from Harvard as a Soros Fellow, and a Masters in Health Policy and Finance from The London School of Economics as a Marshall Scholar. He completed a BS in bioengineering at Rice University. For his academic interests, Steve is focused on consumer education and the intersection between health policy and clinical medicine. His publications have appeared in The New England Journal of Medicine, and PLOS Medicine garnering broad press attention from sources such as CNN, The Washington Post, and The Los Angeles Times. Dr Steve has created a web resource for patients with eczema and contact dermatitis at itchyrash.org. See also Dr Steve’s publications at the end of this post.

Dr Steve Xu MD, MSc

Allergic Contact Dermatitis – What is it?

MarcieMom: Contact dermatitis refer to skin rash that is triggered by contact with an allergen/ irritant. If the immune response is that related to IgE, it would be allergic contact dermatitis; conversely, if the response is due to overtime exposure to the irritant (leading the skin to develop delayed-type hypersensitivity), it is irritant contact dermatitis. 

The thing is a child can have all the different types of dermatitis – atopic, allergic contact and irritant contact.

MarcieMom: Dr Steve, thank you for joining me for this series. The different terms can get very confusing for parents of eczema children. How would you explain the different types of dermatitis to a patient?

Dr Steve Xu:  Right now even within the scientific community, there’s a big debate on what exactly we should call ‘eczema’. At our institution (Northwestern University), this is how we break it down.

The term ‘eczema’ itself actually describes how a certain rash looks.  Atopic dermatitis, allergic contact dermatitis, and irritant contact dermatitis all can cause an ‘eczema’ rash that looks exactly the same. Eczema used as a standalone term isn’t really specific.

For classic childhood ‘eczema’, we refer to this as atopic dermatitis. Allergic and irritant contact dermatitis is defined as a condition where an external agent leads to an eczematous rash. We define the difference between allergic and contact dermatitis here. Basically, an allergic contact dermatitis is defined by an immune-mediated response to an external agent applied to the skin. These reactions typically require only a very small amount of the agent to lead to a rash. Irritant contact dermatitis is not immune related but leads to an indistinguishable eczematous reaction. Typically, more of an external agent must be applied to cause a rash in irritant contact dermatitis.

MarcieMom: In practical terms, is diagnosing the type of dermatitis important? Or knowing the triggers are adequate for management of eczema?

Dr Steve Xu: Yes, definitely. An irritant contact dermatitis usually requires more of the external agent to cause a rash. This is practically important because if you only have an irritant contact dermatitis you may be able to tolerate products that are wash off or rinse off. If you have an allergic contact dermatitis, then we recommend avoidance altogether. Even a little exposure can cause a miserable rash.

Prevalence of Allergic Contact Dermatitis

There is increasing evidence that allergic contact dermatitis is underreported in children and while traditionally thought as unlikely for children, contact dermatitis is becoming more common.

MarcieMom: In the article¹, the top ten pediatric allergens found in personal hygiene products are listed (with the first as having most percentage of children being hypersensitive to it):

1. Neomycin – topical antibiotic, another contact allergen is over-the-counter antibiotic Bacitracin
2. Balsam of Peru – also known as Myroxylon pereirae, chemically related to fragrance and thus used to screen for fragrance allergy
3. Fragrance mix – Of the flowering plants, the Comositae family is the most likely to cause skin sensitization, such as chamomile, dandelion and ragweed; also cross-reactive with propolis (beeswax)
4. Benzalkonium chloride – ammonium compound used as preservative, including in disinfecting wipes and eye drops
5. Lanolin – natural oil from sebum of wool-bearing animals
6. Cocamidopropyl betaine (CAPB) – used as a surfactant
7. Formaldehyde – preservative, also associated with quaternium 15, imidazolindinyl urea (most common), diazolidinyl urea, bronopol, dimethyl-dimethyl hydantoin (this can get very tricky to memorize, readers can refer to this table created by dermapathologist in a previous interview)
8. Methylchlorsothiazolinone (MCI)/ Methylisothiazolinone (MI) – likely to be in bubble baths, soaps, cosmetic products, and baby wipes
9. Propylene glycol – previously common in moisturizers (but many brands stopped including propylene glycol: it has humectant properties and also an emulsifier) and topical steroids
10. Corticosteroids – when using steroid creams, we have to be aware of its potency, but we may now have to know its likelihood of being contact allergen (we will discuss this next week)

Top 10 Pediatric Contact Allergens in Personal Hygiene Products

Other than the above 10, the other well-known contact allergens are cetylstearyl alcohol, sodium lauryl sulphate, pehnoxyethanol, parabens, TEA (triethanolamine) and vitamin E.

Nickel and cobalt are also common contact allergens but less likely that children will come into contact with them.

MarcieMom: It is interesting to note that the above can be found in personal care products, even in those marketed for children. I’m wondering if there is an increase in sensitization in personal hygiene/ skincare products? If so, why? (for instance, is it the increased use of products? Or increased awareness/ patch testing/ consultation)

Dr Steve Xu: The prevalence of contact dermatitis has remained stable overall but certain chemicals are representing a larger share of problems. This is related to industry trends. For example, as formaldehyde was phased out over the past 20 years in personal care products, we’ve seen a growing use of methylisothiazolinone as a preservative. It’s unsurprising that methylisothiazolinone contact allergy is rising rapidly.

Pediatric dermatologists have really worked hard to raise awareness among pediatricians and allergists about contact dermatitis in kids with atopic dermatitis. More than half of kids with atopic dermatitis will have a relevant positive patch test. In general, we’re arguing that kids with atopic dermatitis should be patch tested more and tested for food allergies less. 

Parents need to know that just because a product is labeled “For babies” or “Safe for kids”, it doesn’t mean it’s any different than what products are sold for adults. These are just marketing claims. Statements like “sensitive skin safe” or “organic” also aren’t regulated. Even carefully reading the labels may not be completely fool-proof. Often times, manufacturers do not have to be specific about which fragrance they are using (different fragrances can cause contact dermatitis).

MarcieMom: Practically, this feels like being caught between a rock and a hard place. The baby’s skin loses more moisture, has less lipids and for babies with dry skin, even more so we have to moisturize. Now, we know the common contact allergens to avoid and of course, should take the effort to read the product label and make sure we’re not putting something on our babies with these allergens. YET, the more we put something on our babies, the more likely the skin can become sensitized to it overtime! (for instance, lanolin, CAPB weren’t previously contact allergens)

MarcieMom: Is there a strategy to moisturizing to reduce likelihood of contact dermatitis? For instance, rotating skincare products which one expert has previously mentioned.

Dr Steve Xu: We often have patients come into our clinic with classic allergic contact dermatitis and exclaim: “I haven’t changed my products in years!”. In truth, this is exactly how a contact allergy develops. It’s true that small, continued exposures over time train your immune system to develop an allergy.

Interview with dermatologist Dr Steve Xu, MD

With that being said and to the best of my knowledge, there are no well-designed clinical studies showing that rotating skincare products reduces the risk of future allergic contact dermatitis. I’m hesitant to recommend this strategy.

Here’s some practical advice to perhaps help answer this question. Let’s say you have a child with atopic dermatitis and it’s fairly well controlled. Over the course of a period of time, let’s say the atopic dermatitis has taken a turn for the worst and is not getting better with optimal therapy. Or, let’s say that that the atopic dermatitis is appearing in areas it never has before (e.g. belly button, waistband, wrist). Then, this is a time to consider whether there is a simultaneous allergic or irritant contact dermatitis. Patch testing would be recommended.

If there is a relevant positive patch test, than this is the time to follow a safe list. Severely limiting what skincare products or household products can be used in the absence of a patch-test proven allergen may be overkill.

MarcieMom: Thank you Dr Steve for helping us to understand more about contact dermatitis; for me, I’ve learnt that there is practical benefit of knowing the type of dermatitis one is suffering from, and being mindful of the possible development of contact dermatitis for an eczema child. Look forward to next week where we will discuss more about skincare product, prevalence of contact dermatitis in kids and corticosteroids.

References:

1. Hannah Hill, Alina Goldenberg, Linda Golkar, Kristyn Beck, Judith Williams & Sharon E. Jacob (2016): Pre-Emptive Avoidance Strategy (P.E.A.S.) – addressing allergic contact dermatitis in pediatric populations, Expert Review of Clinical Immunology, DOI: 10.1586/1744666X.2016.1142373

For some of Dr Steve’s publications, see below:

1. Xu S, Walter JR and Bhatia A. Online Reported User Satisfaction with Laser and Light Treatments: Need for Caution. Dermatologic Surgery. Published online September 9th, 2016. DOI: 10.1097/DSS.0000000000000862.
2. Xu S, Kwa M, Agarwal A, Rademaker A, and Kundu RV. Sunscreen Product Performance and Other Determinants of Consumer Preference. JAMA Dermatology. 2016. 152(8):920-927.
3. Walter JR and Xu S. Therapeutic Transdermal Drug Innovation from 2000-2014: Current Status and Future Outlook. 2015. Drug Discovery Today. 2015. 20(11):1293-1299.
4. Walter JR and Xu S. Topical Drug Innovation from 2000 through 2014. JAMA Dermatology. 2015. 151(7):792-794.
5. Xu S, Heller M, Wu PA and Nambudiri VE. Chemical Burn Caused by Topical Application of Garlic Under Occlusion. Dermatology Online Journal. 2014. 20(1). URL: https://escholarship.org/uc/item/88v527wg.

Eczema Blues