Background: Hydroperoxides of limonene (Lim‐OOHs) and linalool (Lin‐OOHs) are potent contact sensitizers. Objectives: To investigate the prevalence of positive patch test (PT) reactions to Lim‐OOHs and Lin‐OOHs in consecutive patients, their demographic factors and concomitant reactions. Methods: Between 7/2018 and 12/2020, Lim‐OOHs 0.3% pet. and Lin‐OOHs 1% pet. were patch tested in 5511 consecutive patients. We assessed PT reactivity and analysed data from patients with either positive or negative PTs to Lim‐OOHs and Lin‐OOHs. Results: Positive PT results to Lim‐OOHs (n = 170, 3.1%) and Lin‐OOHs (n = 483, 8.8%) were frequent. Most of the positive reactions were weak (LimOOHs n = 134/LinOOHs n = 429), and even more frequently, doubtful (n = 252/n = 578) or irritant reactions (n = 81/n = 178) were documented. PT reactivity to Lim‐OOHs and Lin‐OOHs was increased in patients with irritant reactions to sodium lauryl sulphate (SLS). The proportion of leg dermatitis and concomitant positive reactions to fragrances and essential oils was increased in patients with reactivity to these hydroperoxides. Conclusion: The observed reaction pattern suggests that both test preparations display an irritant potential with an increased risk of false positive reactions. Preparations should be chemically monitored in order to reduce irritancy. Mindful interpretation of PT results and aimed patch testing of lower concentrations is recommended. [ABSTRACT FROM AUTHOR]
Background: Patch test (PT) readings are recommended after 48 h and 72 h (D3). An additional day 7 (D7) reading has been suggested by some, although data on efficient patient selection are scarce. We investigated positive D7 reactions regarding (i) allergens in the baseline series and additional PT series of the German Contact Dermatitis Research Group (DKG) and (ii) characteristics of the patients tested. Methods: Retrospective, multicentre analysis of 190 allergens derived from 17 DKG test series in 4687 patients with an additional D7 reading. Patients were patch tested with the baseline series and additional series, if required. Occurrence of novel D7 reactions as well as increasing skin reactions from D3 to D7 was analysed separately. Results: Depending on the allergen tested, waiving D7 readings would have missed 4.4–26.8% of positive PT results. Patch test series with the highest number of novel D7 reactions were baseline series, metal series, and leather/shoe series. New positive reactions on D7 were associated with age over 50 years and with a negative irritant control containing sodium lauryl sulphate. Of note, application of the PT allergens for 48 h instead of 24 h was positively associated with late PT reactions. Conclusion: Within the most frequently tested allergens, without late readings, on average 11.7% of sensitizations would have been missed. Novel late reacting allergens were identified. This study comprehensively dissects patient‐, allergen‐ and test‐dependent parameters in support for D7 readings. We propose to always consider late readings individually based on effort‐benefit considerations. [ABSTRACT FROM AUTHOR]
Of 131 patch-test positive patients, 24 (18.3%) reacted to both preparations, 98 (74.8%) to FMI only, and 9 (6.9%) to OM and not to FMI, although OM is a constituent of FMI. Keywords: allergic contact dermatitis; delayed reactions; fragrance; fragrance mix I; late reactions; oak moss absolute; patch test; patch test active sensitization EN allergic contact dermatitis delayed reactions fragrance fragrance mix I late reactions oak moss absolute patch test patch test active sensitization 54 57 4 12/17/21 20220101 NES 220101 Patch test reactions that become positive de novo at around day 7 (D7) are called "late" patch test reactions,1 and are frequently seen after patch testing neomycin, for example.2 Reactions beyond D7 ("very late reactions") may indicate active sensitization.1,3 However, very late reactions (2 to 4 weeks after patch testing) without being linked to active sensitization have also been observed.4-6 We were interested in very late reactions (beyond D7) in patch testing fragrance mix I (FMI) and oak moss absolute (OM). Regarding all positive reactions, 11/136 (8.1%) of FMI-positive patients and 11/45 (24.4%) of OM-positive patients showed very late reactions (Table 1). 1 TABLEResults of reading fragrance mix I (FMI) and oak moss absolute (OM) in n = 1789 patients at different points of time HT
N patients
Positive D3(D4)
% D3(D4)
Late positive D4-D7
Very late positive. Allergic contact dermatitis, delayed reactions, fragrance, late reactions, oak moss absolute, patch test, patch test active sensitization, fragrance mix I. [Extracted from the article]
Background: Studies on patch testing with workplace materials and evaluation of current occupational relevance of positive patch test reactions are scarce in patients with occupational dermatitis (OD). Objectives: To identify frequent sensitizations with occupational relevance and to determine the value of patch testing with workplace materials in OD patients. Patients and Methods: Results and clinical data of 654 patients with suspected OD patch tested between 2013 and 2017 were analysed. Results: Occupational allergic contact dermatitis was diagnosed in 113 (17.3%) patients. Mechanics had the widest range of occupational sensitizations. Sensitization to epoxy resin was rated occupationally relevant in almost all handicraft trades. Among positive patch test reactions to workplace products, those to water‐based metal working fluids and leave‐on cosmetic products were most frequent. Despite frequent testing, protective gloves only rarely elicited positive reactions. Preservatives and rubber compounds were most frequently identified as currently occupationally relevant. Conclusions: Rubber allergy is occupationally relevant especially in healthcare workers and cleaners. Generally, preservatives including formaldehyde releasers are important allergens in OD patients. Leave‐on cosmetic products must not be forgotten as allergen sources. Patch testing both workplace materials and standardized test preparations has a complementary value and is beneficial for the diagnostic work‐up of OD patients. Highlights: Patch testing of workplace materials and standardized test preparations has a complementary value in the diagnostic work‐up of occupational dermatitis patients.Mechanics should be patch tested in a broad fashion, including rubber, metal working fluids, epoxy resin systems, and leave‐on products.Epoxy resin systems exhibit current occupational relevance in almost all high‐risk professions of the handicraft sector. [ABSTRACT FROM AUTHOR]
We report two patients with contact allergy to diclofenac and subsequent tolerance in oral challenge tests. Allergic contact dermatitis (ACD) after topically applied diclofenac1,2 and type IV reactions after oral intake are rarely reported.3 To date, no study exists on possible oral tolerance in patients with contact allergy to topical diclofenac. Keywords: allergic contact dermatitis; case report; diclofenac; systemic tolerance EN allergic contact dermatitis case report diclofenac systemic tolerance 41 43 3 12/17/21 20220101 NES 220101 Diclofenac (CAS 15307-86-5) is a widely used non-steroidal anti-inflammatory drug (NSAID). [Extracted from the article]
Keywords: allergic contact dermatitis; clinical epidemiology; commerce; contact sensitization; export; import; propolis; trade EN allergic contact dermatitis clinical epidemiology commerce contact sensitization export import propolis trade 722 724 3 11/18/21 20211201 NES 211201 Propolis is a natural product that consists of more than 100 compounds and shows great compositional variation depending on its origin.1 The most common poplar-type propolis is produced by honeybees in China, Europe, and North America, and is characterized by several caffeates as major allergens.2 The Information Network of Departments of Dermatology (IVDK) and others recently observed increasing rates of propolis sensitization.3,4 We aimed to identify causes of increasing sensitization to propolis using IVDK and German trade data. Since 2016, increased import and decreased export of propolis to and from Germany, respectively, probably indicate increased propolis use and exposure, which most likely explains the upward trend of propolis sensitization. [Extracted from the article]
Rahrig, Sebastian, Dettmann, Judith M., Brauns, Birka, Lorenz, Verena N., Buhl, Timo, Kezic, Sanja, Elias, Peter M., Weidinger, Stephan, Mempel, Martin, Schön, Michael P., and Braun, Andrea
Background: Filaggrin (Flg) and hornerin (Hrnr) share similar structural and functional features. Both proteins have been implicated as essential proteins for skin barrier maintenance. Loss‐of‐function mutations of these genes constitute a risk factor for atopic dermatitis and eczema‐related asthma. Furthermore, both FLG and HRNR protein levels are downregulated in patients with atopic dermatitis. Thus, mice deficient for Flg and Hrnr provide a novel model to study skin barrier impairment and the susceptibility for cutaneous inflammation. Methods: By using appropriate targeting vectors and breeding strategies, we established a homozygous FlgHrnr double‐deficient (FlgHrnr−/−) mouse model lacking both genes including the intergenomic sequence. Results: Neonates appeared normal, but developed a transient scaly phenotype with overall flaky appearance, but no overt skin phenotype in adulthood, thereby reflecting a subclinical barrier defect seen in humans. Structurally, FlgHrnr−/− mice displayed a markedly reduced granular layer and a condensed cornified layer. Functionally, FlgHrnr−/− mice showed permeability abnormalities and metabolic aberrations regarding the production of natural moisturizing factors (NMFs) in the stratum corneum. Surprisingly, although the immune system revealed no aberrations under steady‐state conditions, FlgHrnr−/− mice are predisposed to mount an allergic contact dermatitis, especially at hapten threshold levels eliciting allergic reactions. Conclusions: Together, our FlgHrnr−/− mouse model nicely reflects the epicutaneous sensitization susceptibilities and inflammatory reactions to environmental insults in humans with impaired skin barrier functions. [ABSTRACT FROM AUTHOR]