Sofa dermatitis: Value of patch test with 2-(thiocyanomethylthio)benzothiazole.

BACKGROUND: In 2008, numerous cases of allergic contact dermatitis caused by leather chairs (sofa dermatitis) were reported, with dimethylfumarate being the culprit allergen. However, octylisothiazolinone, methylisothiazolinone and cobalt have also been associated with cases of sofa dermatitis. An antifungal agent, 2-(thiocyanomethylthio)benzothiazole (TCMTB), has also previously been described as a contact allergen in leather. MATERIALS AND METHODS: Seven patients were referred to the Department of Dermatology of the Cliniques universitaires Saint-Luc, Brussels, Belgium with suspicion of allergic contact dermatitis caused by leather sofas. They were patch tested with the European Baseline Series, additional series (according to the patients' history and clinical aspect of the eruption), dimethylfumarate (4/7 patients) and with TCMTB. RESULTS: All seven patients presented a positive reaction to TCMTB and only one presented a concomitant positive reaction to dimethylfumarate. All patients showed clinical improvement after avoiding contact with their leather sofa. CONCLUSION: 2-(Thiocyanomethylthio)benzothiazole (TCMTB) is probably an underestimated allergen present in leather chairs (responsible for the so-called 'sofa dermatitis'), and more generally in leather objects. It is, therefore, important to test with TCMTB 0.1% petrolatum in case of contact dermatitis related with leather products.

Chilblains observed during the COVID-19 pandemic cannot be distinguished from classic, cold-related chilblains

Background: Type 1 interferon (IFN-I) response induced by SARS-CoV-2 has been hypothesized to explain the association between chilblain lesions (CL) and SARS-CoV-2 infection. Objective: To explore direct cytopathogenicity of SARS-CoV-2 in CL and to focus on IFN-I expression in patients with chilblains. Materials & Methods: A monocentric cohort of 43 patients presenting with CL from April 2020 to May 2021 were included. During this period, all CL were, a priori, considered to be SARS-CoV-2-related. RT-qPCR on nasopharyngeal swabs and measurements of anti-SARS-CoV-2 antibodies were performed. Anti-SARS-CoV-2 immunostainings as well as SARS-CoV-2 RT-qPCR were performed on biopsy specimens of CL and controls. Expression of MX1 and IRF7 was analysed on patients' biopsy specimens and/or PBMC and compared with controls and/or chilblains observed before the pandemic. Serum IFN-α was also measured. Results: RT-qPCR was negative in all patients and serological tests were positive in 11 patients. Immunostaining targeting viral proteins confirmed the lack of specificity. SARS-CoV-2 RNA remained undetected in all CL specimens. MX1 immunostaining was positive in CL and in pre-pandemic chilblains compared to controls. MX1 and IRF7 expression was significantly increased in CL specimens but not in PBMC. Serum IFN-α was undetected in CL patients. Conclusion: CL observed during the pandemic do not appear to be directly related to SARS-CoV-2 infection, either based on viral cytopathogenicity or high IFN-I response induced by the virus.

Evolution of methylisothiazolinone sensitization: A Belgian multicentric study from 2014 to 2019.

BACKGROUND: In the 2010s an epidemic of allergic contact dermatitis to methylisothiazolinone (MI) occurred in Europe. European authorities banned the use of methylisothiazolinone in leave-on cosmetics in 2017 and limited its use in rinse-off products in 2018. OBJECTIVES: To investigate the sensitization rate to MI in Belgium between January 2014 and December 2019, and to assess cosensitizations to octylisothiazolinone (OIT) and benzisothiazolinone (BIT) in MI-sensitized patients. METHODS: A retrospective study of patch test results with MI, OIT, and BIT observed in patients attending five Belgian hospitals. RESULTS: Overall, 560 of 10 029 patients (5.58%) had a positive patch test reaction to MI, and its sensitization rate decreased from 7.9% in 2014 to 3.1% in 2019. Rinse-off cosmetics, paints, and detergents were the most prevalent sensitization sources in recent years. Simultaneous reactions readily occurred to OIT, and, surprisingly, and increasingly, also to BIT. CONCLUSIONS: Contact allergy to MI in Belgium has reached a pre-epidemic level, reflecting the impact of recent regulatory measures. Leave-on cosmetics, in contrast to rinse-off products, have almost disappeared as sensitization sources in Europe. Paints and detergents also remain problematic. The remarkably high number of patients (co)sensitized to BIT should be a focus of future research.

Unique molecular signatures typify skin inflammation induced by chemical allergens and irritants.

BACKGROUND: Skin exposure to chemicals may induce an inflammatory disease known as contact dermatitis (CD). Distinguishing the allergic and irritant forms of CD often proves challenging in the clinic. METHODS: To characterize the molecular signatures of chemical-induced skin inflammation, we conducted a comprehensive transcriptomic analysis on the skin lesions of 47 patients with positive patch tests to reference contact allergens and nonallergenic irritants. RESULTS: A clear segregation was observed between allergen- and irritant-induced gene profiles. Distinct modules pertaining to the epidermal compartment, metabolism, and proliferation were induced by both contact allergens and irritants; whereas only contact allergens prompted strong activation of adaptive immunity, notably of cytotoxic T-cell responses. Our results also confirmed that: (a) unique pathways characterize allergen- and irritant-induced dermatitis; (b) the intensity of the clinical reaction correlates with the magnitude of immune activation. Finally, using a machine-learning approach, we identified and validated several minimal combinations of biomarkers to distinguish contact allergy from irritation. CONCLUSION: These results highlight the value of molecular profiling of chemical-induced skin inflammation for improving the diagnosis of allergic versus irritant contact dermatitis.

COVID toes: where do we stand with the current evidence?

BACKGROUND: Numerous of cases of chilblains have been observed, mainly in young subjects with no or mild symptoms compatible with COVID-19. The pathophysiology of these lesions is still widely debated and an association with SARS-CoV-2 infection remains unconfirmed. OBJECTIVES: This paper focus on the unresolved issues about these COVID toes and in particular whether or not they are associated with COVID-19. ARGUMENTS: The temporal link between the outbreak of chilblains and the COVID-19 pandemic is a first suggests a link between the two events. Positive anti-SARS-CoV/SARS-CoV-2 immunostaining on skin biopsy of chilblains seem to confirm the presence of the virus in the lesions, but lack specificity and must be interpreted with caution. Conversely, RT-PCR and anti-SARS-CoV-2 serology were negative in the majority of patients with chilblains. Therefore, SARS-CoV-2 infection can be excluded, with relative certainty, even after accounting for possible lower immunization in mild/asymptomatic patients and for some differences in sensitivity/specificity between the tests used. Some authors hypothesize that chilblains could be the cutaneous expression of a strong type I interferon (IFN-I) response. High production of IFN-I is suggested to be associated with early viral control and may suppress antibody response. However, the absence of other cutaneous or extracutaneous symptoms as observed in other interferonopathies raises unanswered questions. To date, a direct link between chilblains and COVID-19 still seems impossible to confirm. A more indirect association due to lifestyle changes induced by lockdown is a possible explanation. Improvement of chilblains when protective measures were adopted and after lifting of lockdown, support this hypothesis. CONCLUSION: Conflicting current evidence highlights the need for systematic and repeated testing of larger numbers of patients and the need for valid follow-up data that take into consideration epidemic curves and evolution of lockdown measures.

A systematic review examining the relationship between food insecurity and early childhood physiological health outcomes.

Food insecurity, or limited access to nutritious foods, is a significant public health concern especially among vulnerable populations including infants and young children in low-income households. While literature to date has thoroughly examined the psychological and behavioral impacts of food insecurity on children, no known study to date has specifically synthesized the literature exploring the relationship between food insecurity and physiological health outcomes during early childhood. The purpose of this study was to review the literature on physiological health outcomes associated with food insecurity during early childhood among children aged 0-5 years in developed countries. Our literature search sources included PubMed, PsycInfo, CINAHL, and Embase databases. A total of 657 articles published up to September 2019 were reviewed for eligibility by two coders, with a third reviewer in cases of disagreement. Eighty-three articles remained after screening by abstract, with a final 27 studies ultimately included in the final synthesis. This review is registered with PROSPERO and adhered to PRISMA guidelines. In total, 20 articles (74%) noted significant relationships between food insecurity and physiological health outcomes in young children. Findings included an association with overweight or obesity (n = 9), anemia (n = 3), poor child health (n = 3), low birth weight (n = 3), chronic illness (n = 1), special health care needs (n = 1), and increased cortisol (n = 1), in young children who experience food insecurity. Identifying relationships between food insecurity and health outcomes during early childhood has the potential to inform future prevention interventions to reduce health disparities in these vulnerable populations.

Evaluation of Chilblains as a Manifestation of the COVID-19 Pandemic.

Importance: During the coronavirus disease 2019 (COVID-19) pandemic, several cases of chilblains have been reported. Objective: To determine if chilblains are associated with COVID-19. Design, Setting, and Participants: This monocentric case series was conducted at the Department of Dermatology at Cliniques universitaires Saint-Luc, a tertiary care hospital in Brussels, Belgium, between April 10 and April 17, 2020. We evaluated a total of 31 referred patients who had recently developed chilblains. Main Outcomes and Measures: Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) was used to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA on nasopharyngeal swabs for all patients and in skin biopsy specimens for 22 patients. Blood samples from all patients were tested for specific anti-SARS-CoV-2 immunoglobulin (Ig) M and IgG antibodies. All patients had extended blood analyses. Histologic (22 patients) and immunofluorescence examinations (15 patients) were performed on the skin biopsy specimens. Results: The 31 patients were generally in good health; most were teenagers or young adults, and 19 were women. Histopathologic analysis of skin biopsy specimens (22 patients) confirmed the diagnosis of chilblains and showed occasional lymphocytic or microthrombotic phenomena. Immunofluorescence analyses showed vasculitis of small-diameter vessels in 7 patients. In all patients, SARS-CoV-2 RNA remained undetected by RT-PCR on nasopharyngeal swabs and in biopsy samples of the skin lesions. The IgM and IgG antibody titers were negative for SARS-CoV-2 in all patients (<1.0 arbitrary unit/mL). No significant abnormalities in blood test results were suggestive of systemic disease. Antinuclear antibody titers were low in 7 patients and higher in 1 patient. Conclusions and Relevance: Chilblains appeared not to be directly associated with COVID-19 in this case series. Lifestyle changes associated with community containment and lockdown measures are a possible explanation for these lesions.

Adverse cutaneous reaction to diabetic glucose sensors and insulin pumps: Irritant contact dermatitis or allergic contact dermatitis?

BACKGROUND: Adverse cutaneous reactions to diabetes medical devices (glucose sensors and insulin pumps) are described, notably allergic contact dermatitis (ACD) with isobornyl acrylate (IBOA) and N,N dimethylacrylamide (DMAA) as the main allergen. OBJECTIVES: To determine if all cases of adverse cutaneous reactions observed with diabetes medical devices (ie FreeStyle Libre, Enlite sensors or insulin pumps), referred to our department with suspected allergies are confirmed as ACD. PATIENTS AND METHODS: Fifty-two patients who presented skin reactions to diabetes medical devices were patch tested with the European baseline series, a plastic and glues series, a (meth) acrylates series, a piece of the adhesive part of the device, as well as IBOA 0.1% and DMAA 0.1% pet. RESULTS: Seventeen patients had no positive reaction to IBOA nor to the adhesive part of the device; 11 of these also tested with DMAA with negative result. No other relevant allergen was identified. CONCLUSION: Some cutaneous reactions, otherwise very similar to those of patients sensitized to IBOA, can be explained either by the presence of an untested allergen not yet discovered, or by irritant contact dermatitis. Therefore, European legislation on the full labelling of ingredients by manufacturers, in order to facilitate the identification of allergens and irritants, is imperative.

Isobornyl Acrylate.

Multidisciplinary collaboration between several European dermatology departments has identified isobornyl acrylate (IBOA; CAS 5888-33-5), once deemed a low-risk sensitizer, as a major culprit contact allergen in glucose sensors and insulin pumps, medical devices used by diabetes patients worldwide. Although the patch test modalities of IBOA have been fairly well characterized, intriguing questions remain. For example, its cross-reactive profile to other acrylates remains to be determined, and the striking occurrence of concomitant positive patch test reactions to sesquiterpene lactones needs to be further elucidated. Importantly, the path to its discovery as a contact sensitizer in diabetes devices and the difficulties that were associated with this quest illustrate that apparent difficulties in obtaining sufficient cooperation from the medical device industry may seriously hamper the correct workup of cases of allergic contact dermatitis. The IBOA saga will convince companies to lend more cooperation to dermatologists and policymakers to side with patients and physicians when it comes to updating medical device regulations, including the compulsory labeling of medical devices in general and of diabetes devices in particular.

Contact dermatitis caused by glucose sensors in diabetic children.

BACKGROUND: Allergic contact dermatitis caused by glucose sensors has been recently described in diabetics, mostly in adult patients. Isobornyl acrylate and N-N dimethylacrylamide are the potent causative agents. OBJECTIVES: To describe a child population with contact dermatitis caused by glucose sensors, determine the causative allergen, and assess the prevalence of isobornyl acrylate (IBOA) sensitization. PATIENTS AND METHODS: Overall, 12 children with a reaction to medical devices, either glucose sensors or insulin sets, were patch tested with the European baseline series, glues and rubber, (meth) acrylates series, and with piece of the adhesive part of the glucose sensor FreeStyle Libre. Isobornyl acrylate 0.1% pet. was patch tested in 11 patients, and N-N dimethylacrylamide in two. Some patients were tested with adhesive parts of the infusion set. RESULTS: Overall, 10 children reacted to the adhesive part of the sensor FreeStyle Libre, and 10 children were sensitized to IBOA. One patient turned out to be negative in all patch tests. CONCLUSION: Allergic contact dermatitis caused by glucose sensors is common in the pediatric diabetic patient population. Like in the adult patient population, IBOA was the culprit allergen, with 83.3% sensitization prevalence in children exhibiting adverse cutaneous reactions caused by FreeStyle Libre.

Allergic contact dermatitis caused by isobornyl acrylate in the Enlite glucose sensor and the Paradigm MiniMed Quick-set insulin infusion set.

BACKGROUND: The FreeStyle Libre glucose sensor has caused many cases of allergic contact dermatitis, and isobornyl acrylate (IBOA) in this sensor has been identified as one of the culprit allergens. OBJECTIVES: To report on the presence of IBOA in devices produced by Medtronic, namely, the Enlite sensor and the insulin infusion set Paradigm MiniMed Quick-set. PATIENTS AND METHODS: Five patients reacting to the glucose sensor Enlite and/or the insulin infusion set Paradigm MiniMed Quick-set observed in three clinics (two Belgian and one Swedish) were patch tested with the baseline and other series, as well as with IBOA; four of them also with pieces of adhesive patches from the devices, and two with a thin layer chromatogram of Enlite glucose sensor extracts. Gas chromatography-mass spectrometry (GC-MS) analyses were performed. RESULTS: Four patients reacted to IBOA and one to colophonium, a known allergen in Enlite, and three to the adhesive part of the sensor or the insulin infusion set. IBOA was identified in the sensor by GC-MS, and its presence was indicated in the infusion set. CONCLUSIONS: IBOA is a contact allergen in Enlite glucose sensor, and likely also in the infusion set. Therefore, these devices are not suitable alternatives for patients sensitized to the FreeStyle Libre sensor.