Medical news on eczema by dr daniel wallach - october 2020
Discover the 4th scientific publication in 2020 by Dr WallachRead more
Nakamura T, Haider S, Colicino S et al; STELAR investigators.
Different definitions of atopic dermatitis: impact on prevalence estimates and associated risk factors.
Br J Dermatol 2019;181:1272-1279.
Atopic dermatitis (AD) is the most common skin disease. Patients have long suffered from the enormous burden of this disease and its impact on quality of life, which have been well documented. The literature on AD is extensive, too extensive according to some. Here, we try to extract useful insights from this abundant research. These issues should be the subject of far-reaching studies involving a huge number of cases. This goal, however, comes up against a rather awkward problem: oddly enough, we have yet to reach a consensus on the definition of AD. Granted, the diagnostic criteria proposed by Hanifin and Rajka in 1979, as well as those developed by a British working group in 1994, have been unanimously acclaimed, but are generally considered to be overly complicated for use in epidemiological studies, often based on questionnaires. The formulation of the questions and interpretation of the answers are rarely standardized. By analyzing recent publications on the topic, the authors identified 59 different definitions of AD. They broke down these definitions into four types of AD cases, based on parents’ or patients’ responses to questions on whether a doctor ever mentioned eczema and if they experience chronic itching in folds. They then applied these definitions to a cohort of British children being monitored for asthma and/or allergies. The primary conclusion was that, depending on the definition used, AD prevalence varies greatly: between 22% and 33% for one cohort, and 12% and 22% for another. Similarly, the presence of risk factors, such as a filaggrin mutation (2% of cases), varies from one definition to another. The ambiguity is thus significant. It should be noted that the authors of this study are pediatricians, respirologists, immunologists, and dermatologists. In Great Britain, which has a shortage of specialists and a very high prevalence of AD, first-line treatments are lacking in dermatological expertise. A clinical exam should, nevertheless, be incorporated into the definitions of AD, at least until immunological and genetic research has identified a biological criterion that would answer this nagging question once and for all.
Totté JEE, Pardo LM, Fieten KB, et al.
Nasal and skin microbiomes are associated with disease severity in pediatric atopic dermatitis.
Br J Dermatol 2019;181:796-804.
The gastrointestinal and skin microbiomes of atopic children have been the subject of a number of studies, but so far the nasal microbiome has received very little attention. This publication thus provides a detailed analysis of the skin and nasal microbiomes of 48 Dutch children with atopy under 18 years of age. Keeping in mind the major challenge when conducting studies on atopic cohorts, the authors first specified the diagnostic criteria, using the above-mentioned British working group, and the severity, based on the EASI score at the time samples were taken.
Like most of the studies on the bacteriology of AD, this one identified a link between the composition of the microbiomes and the severity of AD, with staphylococci playing a primary role. However, half the children involved had no staphylococci on their skin. The bacterial communities on the skin and nose are different. Plus, in addition to staphylococci, other bacteria, such as nasal moraxella, appeared to play a potential role. But if you were hoping for practical findings, you are in for some disappointment. Longitudinal studies involving several carefully examined patients are needed in order to truly prove whether the nasal microbiome affects AD. None of the authors ventured to propose and therapeutic recommendations. We are only just beginning to explore the microbial dimension of AD.
Maghen P, Unrue EL, Oussedik E, Cline A, Cardwell LA, Feldman SR.
Regardless of how risks are framed, patients seem hesitant to use topical steroids for atopic dermatitis.
Br J Dermatol 2019;181:842-844.
Whenever patients are given the choice of several treatment options, how doctors frame them—the words they use and the way they talk about them—clearly influences their decision-making. In particular, insisting on the potential drawbacks of a treatment or, inversely, the disadvantages of a spontaneous development is likely to influence patients’ choices and compliance. This depends on their level of risk aversion, which varies from one person to the next. In this study, the authors explored whether the framing of a potential risk of topical corticosteroids (thinning of the skin), compared to the risk of letting the eczema progress without treatment, influenced patients’ desire to follow the treatment.
613 adults with atopy were divided into several groups who were provided with information, framed in different ways, on the risk of skin atrophy associated with a treatment that improves eczema symptoms or on the risk of forgoing treatment and continuing to suffer with eczema.
In effect, patients responded to both approaches in much the same way. The main conclusion of this study was that, in any case, there was a certain reluctance to use the treatment presented in such a way, evaluated at 5/10. However, when the information indicated a 10% risk of skin thinning compared to an 80% chance of improvement, patients were willing to proceed with treatment at an average of 8/10.
McClanahan D, Wong A, Kezic S, et al.
A randomized controlled trial of an emollient with ceramide and filaggrin-associated amino acids for the primary prevention of atopic dermatitis in high-risk infants.
J Eur Acad Dermatol Venereol 2019;33:2087-2094.
Primary prevention of atopic dermatitis has been the goal of many researchers for a number of years. Immuno-allergic approaches, or changes to the environment, have all failed thus far. However, two studies published in late 2014 indicated that applying an emollient daily from birth may reduce AD prevalence in at-risk newborns by half. These results have sparked a great deal of hope, and a wide-reaching study is under way in the U.K. (BEEP study) in an attempt to confirm these results on a broader scale.
That was also the objective of this American team, who unveiled their results in a randomized controlled study comparing the daily application of an emollient containing a ceramide and NMF amino acids with the application of “routine” skin care in newborns at risk for atopy. The article offers valuable insight through its results as well as through the challenges faced, the main one being recruitment. The authors were able to recruit just 100 children, although more than 200 were needed to obtain significant results. Apparently, parents convinced of the benefits of using an emollient were unwilling to participate due to the risk of being randomly selected for the control group. Generally speaking, enrolling your newborn in a randomized clinical study, even one involving a hydrating cream, is hardly an appealing prospect. The results are thus positive but insignificant: at the age of 1 year, AD prevalence was 13.2% in the emollient group and 25% in the control group. Given the similarity between the two groups, there is no difference stricto sensu. Does this mean the emollient is ineffective? Or is it the result of parents in the control group using an emollient as well, although less often? We cannot know for sure. In addition, the study included an analysis of the skin microbiomes and biophysical properties of the barrier. Once again, nothing significant. We must, therefore, conclude that neonatal emollient treatment may be beneficial but that it cannot, as of yet, be confirmed.
Irvine AD, Mina-Osorio P.
Disease trajectories in childhood atopic dermatitis: an update and practitioner's guide.
Br J Dermatol 2019;181:895-906
Although the subject of extensive research, the complexities of atopic dermatitis remain poorly understood to this day. Epidemiology is a particular complex science as well. For this reason, we really appreciate A Irvine and P Mina-Osorio for analyzing several recent wide-reaching epidemiological studies, involving thousands of children, in order to decipher and summarize them. The objective was to help parents and caretakers anticipate, as much as possible, the progression of atopic dermatitis from two perspectives: the risk of persistent AD continuing beyond childhood, and the risk of associated allergic comorbidities (Atopic March). Their results present no figures, but we know that, in the majority of cases, AD goes away in childhood, and that only a minority of patients experience prolonged and/or systemic progressions, probably between 20% and 40% of the children affected. But which children? That is the question. Well, through the recently published cohort analysis, the authors have been able to propose a practical guide for identifying “at-risk” patients. The risks include mainly:
One would expect the authors to create a predictive score based on these elements, although they do not. They do, however, outline five common scenarios along with practical steps to take in response in order to prevent prolonged progressions and respiratory allergies as much as possible. In most children, simply treating the symptoms is sufficient. If, however, a risk of asthma is identified in the clinical history, early specialist intervention may be necessary.
Mowitz M, Fornander L, Hosseiny S, Ryberg K, Bruze M.
Patch Testing with Isobornyl Acrylate in 16 Swedish Patients with Contact Dermatitis from Glucose Sensors and/or Insulin Pumps.
Acta Derm Venereol 2019, published online 10 July.
Herman A, Baeck M, de Montjoye L, et al.
Allergic contact dermatitis caused by isobornyl acrylate in the Enlite glucose sensor and the Paradigm MiniMed Quick-set insulin infusion set.
Contact Dermatitis 2019;81:432-437.
Skin sensors measure blood sugar levels continuously and are a welcomed advancement for insulin-dependent diabetics (type-1 diabetes). Unfortunately, several cases of contact allergies have been reported recently regarding either the sensors or the insulin pump. Both these articles by teams of specialized dermatologists and allergologists confirm that the culprit is isobornyl acrylate (IBOA), the allergenic potential of which was unknown until now. 16 Swedish diabetic patients, including adults and children, were examined for contact eczema in an area where a sensor or insulin pump device is worn. The time it took for eczema to appear varied, ranging from one month to 18 to 24 months. 11 patients turned out to be allergic to the IBOA, while some tested positive for one or more allergens in the standard battery. The Belgian authors (A Herman, et al) reported five similar observations, discussed in detail. Four patients reacted to the IBOA, one to the colophony, and three to the adhesive. The authors analyzed the devices in question using gas chromatography and mass spectrometry, which enabled them to demonstrate the presence of IBOA objectively. Patch-tests were also conducted with the chromatography bands. For patients with an allergy to IBOA, there is no easy solution. They can try to protect their skin using barrier creams or protective films, but this may alter the sensors’ performance. The authors mention that the manufacturing company of the devices in question did not respond to their requests for collaboration. They conclude that regulatory changes are needed and that manufacturers should be obligated to publish the complete chemical composition of their devices.
Rolls S, Chowdhury MM, Cooper S, et al.
Recommendation to include hydroxyethyl (meth)acrylate in the British baseline patch test series.
Br J Dermatol 2019;181:811-817.
15 British and Irish dermato-allergology centers participated in this study which aimed to demonstrate the magnitude of the methacrylate contact allergy. Out of 5,920 patients tested for eczema, 140 tested positive for 2-HEMA (2-Hydroxyethyl methacrylate), used as a “screening” patch-test, or for one of the other methacrylates (there are 24 in total, 8 of which are tested here).
Nearly all the patients involved were women, customers or employees of nail salons or nail bars, which have recently become very popular and which use methacrylates (gel nails, polish, etc.). This prevalence prompted the authors to recommend adding methacrylates to the standard European battery, which should be completed soon. Methacrylate-related eczema most often affects the area where they were applied (nails, skin around the nails), but it also appears on the face and, more rarely, other areas of the body.
This sensitization is likely to lead to problems later on, as methacrylates are used in dentistry and orthopedics and as a surgical glue. Cross-reactions can occur between the different methacrylates, but not with cyanoacrylates. Cross-reaction is unlikely with regard to the above-mentioned IBOA. As soon as is becomes available as a patch-test allergen, however, the authors recommend including it in the methacrylate series, currently used for eczema triggered by nail products or for positive 2-HEMA tests. All of this raises the question of information and prevention among nail care professionals and their customers, which is a difficult problem.
Teo Y, McFadden JP, White IR, Lynch M, Banerjee P.
Allergic contact dermatitis in atopic individuals: Results of a 30-year retrospective study.
Contact Dermatitis 2019;81:409-416.
Atopic dermatitis involves TH2 hypersensitivity, while allergic eczema is linked to TH1 hypersensitivity, so one would expect atopy to protect against contact allergies in some way. However, the atopic skin barrier is hyperpermeable to allergens, which complicates matters. Moreover, studies assessing contact eczema in atopic patients have produced contradictory results. This major study by London dermatologists and allergologists helps, to a certain extent, explain these contradictions. Over the course of 30 years, the authors conducted contact tests on 46,250 patients, of whom approximately one-third had atopy. Here, they indicate the differences in contact sensitization rates between atopic and healthy subjects. Overall, the two populations have many similarities as well as differences which are quantitatively insubstantial yet significant, and which are emphasized by the authors. Atopic patients are less susceptible to contact allergies to nickel (the most common allergen worldwide), cobalt, and primine.
However, they are most often allergic to substances found in cleansing and skin care products or topical medications used over long periods of time. Such substances include mainly preservatives, a corticosteroid, and lanolin. The study concludes, of course, that more research is needed on contact allergies in atopic patients who respond poorly to treatment.
Discover the 4th scientific publication in 2020 by Dr WallachRead more
September 24, 2020, Korea Gyeong Gi-Do Atopy Asthma Education Information Center hold the Atopy Healing Day sponsored by the ECZEMA foundation.Read more