Case Report: Mast cell anergy: absence of symptoms after accidental re-exposure to amoxicillin/clavulanic acid 3 days after anaphylaxis.

Empty mast cell syndrome, also named post anaphylaxis mast cell anergy (PAMA), is a temporary state of loss of mast cell responsiveness after a severe immediate hypersensitivity reaction. In this study, we describe a case of PAMA after accidental re-exposure to amoxicillin in a patient who developed severe anaphylaxis to this drug three days earlier in the operating room. To our knowledge, this report is the second to document this phenomenon.

Comprehensive ophthalmological evaluation in atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD), a chronic Type 2 inflammatory skin disease, is frequently associated with ocular surface diseases (OSD) which may appear or worsen under anti-Type 2-targeted treatments. However, the exact prevalence of OSD and the ophthalmology referral criteria remain ill-defined in AD patients before initiating such biotherapies. OBJECTIVE: We aimed to characterize the prevalence, the nature and the factors related to OSD development in AD that may justify an ophthalmological management. METHODS: A total of 98 consecutive AD inpatients without biological treatment were retrospectively included. These were systematically evaluated by an ophthalmologist during their dermatological care. Clinical and laboratory data were analyzed to characterize OSD and their risk factors. RESULTS: OSD were found in 83/98 AD patients (85%); mainly dry eye syndrome (64%, 63/98), allergic conjunctivitis (42%, 41/98), posterior (33%, 32/98), and anterior blepharitis (27%, 26/98). In AD patients without ocular symptoms, OSD were also frequently found (63%, 12/19) and were mostly mild. Risk factors for OSD were history of allergic rhinitis, allergic sensitization, head and neck AD, ocular symptoms (foreign body sensation in the eye, burning, itching, photophobia), and total IgE level >3000kU/L. CONCLUSION: The prevalence of OSD was high, even in asymptomatic patients. The risk factors identified may indicate the need for ophthalmological examination for therapeutic management, especially when biological agents targeting Type 2 inflammation are considered.

Gene profiling in active dermatitis lesions strengthens the diagnosis of allergic contact dermatitis.

BACKGROUND: Distinguishing between allergic and nonallergic forms of Contact Dermatitis (CD) is challenging and requires investigations based on patch-testing. Early detection of allergy biomarkers in active CD lesions could refine and simplify the management of CD patients. OBJECTIVE: To characterize the molecular signatures of active CD lesions. METHODS: We studied the expression of 12 allergy biomarkers by qRT-PCR in active lesions of 38 CD patients. Allergic CD (ACD) was diagnosed based on patch test (PT) results and exposure assessment. Molecular signatures of active lesions, as well as positive PT reactions, were compared with those of reference chemical allergens and irritants. RESULTS: Nineteen of the 38 CD patients reacted positively upon patch-testing and exposure assessment confirmed ACD diagnosis for 17 of them. Gene profiling of active CD lesions revealed 2 distinct molecular patterns: patients harboring signatures similar to reference allergens (n = 23) or irritants (n = 15). Among the 23 patients with an "allergy signature," we found the 17 patients with confirmed ACD, while no culprit allergen was identified for the 6 other patients. Interestingly, the 15 patients without biomarker induction had negative PT, suggesting that they developed nonallergic CD reactions. CONCLUSION: Molecular signatures from active skin lesions may help to stratify CD patients and predict those suffering from ACD.

Omalizumab Drug Survival in Chronic Urticaria: A Retrospective Multicentric French Study.

BACKGROUND: Omalizumab (OMA) dramatically improves disease control and quality of life in patients with chronic urticaria (CU). OBJECTIVE: We aimed to evaluate the discontinuation patterns of OMA and their determinants in a cohort of French patients with CU. METHODS: We conducted a retrospective multicenter study in 9 French tertiary referral hospitals. All patients diagnosed with either spontaneous (CSU) and/or inducible (CIndU) CU who received at least 1 injection of OMA between 2009 and 2021 were included. We analyzed OMA drug survival and investigated possible determinants using Kaplan-Meier curves and log-rank tests. RESULTS: A total of 878 patients were included in this study; 48.8% had CSU, 10.1% CIndU, and 41.1% a combination of both. OMA was discontinued in 408 patients, but the drug was later reintroduced in 50% of them. The main reason for discontinuing treatment was the achievement of a well-controlled disease in 50% of patients. Half of the patients were still being treated with OMA 2.4 years after the initiation of treatment. Drug survival was shorter in patients with CIndU and in those with an autoimmune background. In atopic patients, OMA was discontinued earlier in patients achieving a well-controlled disease. A longer OMA drug survival was observed in patients with a longer disease duration at initiation. CONCLUSION: In French patients with CU, the drug survival of OMA appears to be longer than that observed in previous studies conducted elsewhere, highlighting discrepancies in prescription and reimbursement possibilities. Further studies are warranted to develop customized OMA treatment schemes based on individual patterns.

Hand eczema in glove-wearing patients.

BACKGROUND: Allergic contact dermatitis to gloves is mostly induced by rubber accelerators. The European baseline series (EBS) appears insufficient to detect glove allergy. Since 2017, it is recommended to use the European rubber series (ERS) and to test the patients' own gloves. OBJECTIVES: To investigate the clinical profile of glove-wearing patients with hand eczema (HE) and to evaluate their sensitisation profile to glove allergens and the value of testing the patients' own gloves. METHODS: We conducted a French multicentre study of patients evaluated for HE between 2018 and 2020 and tested with the EBS, the ERS and their own gloves in patch tests and semi-open (SO) tests. RESULTS: A total of 279 patients were included; 32.6% of patients had positive tests to their own gloves or to glove allergens. Almost 45% of the sensitisations to glove allergens were detected only by the ERS. Among the patients tested both in patch tests and SO tests with their own gloves with positive results, 28% had positive SO tests only. Polyvinylchloride (PVC) gloves were positive in four patients. CONCLUSION: Our series confirms the need to test the ERS. All the patients' gloves must also be tested including PVC gloves. SO tests with gloves are useful as a complement to patch tests.

Discrepancies in the management of acquired cold contact urticaria: Results of a French-speaking urticaria experts questionnaire survey.

Acquired cold contact urticaria (ACU) is a putatively serious condition, because of the risk of anaphylactic shock whenever patients are massively exposed to cold atmosphere/water, raising the question of the prescription of an "emergency kit" with oral antihistamines and epinephrine auto-injector. We performed an online survey to evaluate how French-speaking urticaria experts manage ACU. According to the 2016 consensus recommendations on chronic inducible urticarias, all the participants perform at least 1 of the available provocation tests and 84.2%, 77.8%, and 88.9% prescribe on-label use of second generation anti-H1 antihistamines (2GAH1) as a first line treatment, updosed 2GAH1 as a second line treatment, and omalizumab as a third line treatment, respectively. Interestingly, 44.4% of the practitioners always prescribe a continuous background treatment, versus 11.1% prescribing only on-demand therapy. Also, 11.7% of participants always prescribe an epinephrine auto-injector, 70.6% sometimes do, and 17.6% never do. Finally, 89.5% authorize swimming under strict conditions but 36.8% and 68.4% contra-indicate other water sports and occupational cold exposure, respectively.

Multiple cases of sensitization to an antiseptic containing chlorhexidine digluconate/benzalkonium chloride/benzyl alcohol with different profiles of sensitization in adults and children.

BACKGROUND: An aqueous antiseptic containing "chlorhexidine digluconate/benzalkonium chloride/benzyl alcohol" (CBB) is widely used in France. The only previous documented study dealing with allergic contact dermatitis (ACD) to this antiseptic is one small case series in children. The French Vigilance Network for Dermatology and Allergy (REVIDAL-GERDA) has collected many cases in the last few years. OBJECTIVES: To evaluate the clinical and sensitization profiles of patients diagnosed with ACD to CBB. METHODS: We performed a retrospective study of patients with contact dermatitis to CBB and positive tests to CBB and/or at least one of its components. All patients had to be tested with all components of CBB. RESULTS: A total of 102 patients (71 adults and 31 children) were included. The lesions were extensive in 63% of patients and 55% had delayed time to diagnosis. CBB patch tests were positive in 93.8% of cases. The allergen was identified in 97% of patients, mainly benzyl alcohol in adults (81.7%) and chlorhexidine digluconate in children (54.8%). About 32.4% of the patients were sensitized to several components. CONCLUSION: CBB is a cause of ACD at all ages. The components of the antiseptic should be tested. The sensitization profile seems to be different between adults and children.

Allergies and COVID-19 vaccines: An ENDA/EAACI Position paper.

BACKGROUND: Anaphylaxis, which is rare, has been reported after COVID-19 vaccination, but its management is not standardized. METHOD: Members of the European Network for Drug Allergy and the European Academy of Allergy and Clinical Immunology interested in drug allergy participated in an online questionnaire on pre-vaccination screening and management of allergic reactions to COVID-19 vaccines, and literature was analysed. RESULTS: No death due to anaphylaxis to COVID-19 vaccines has been confirmed in scientific literature. Potential allergens, polyethylene glycol (PEG), polysorbate and tromethamine are excipients. The authors propose allergy evaluation of persons with the following histories: 1-anaphylaxis to injectable drug or vaccine containing PEG or derivatives; 2-anaphylaxis to oral/topical PEG containing products; 3-recurrent anaphylaxis of unknown cause; 4-suspected or confirmed allergy to any mRNA vaccine; and 5-confirmed allergy to PEG or derivatives. We recommend a prick-to-prick skin test with the left-over solution in the suspected vaccine vial to avoid waste. Prick test panel should include PEG 4000 or 3500, PEG 2000 and polysorbate 80. The value of in vitro test is arguable. CONCLUSIONS: These recommendations will lead to a better knowledge of the management and mechanisms involved in anaphylaxis to COVID-19 vaccines and enable more people with history of allergy to be vaccinated.

Preparations of exploration of immediate hypersensitivity to antineoplastic agents: An oncology pharmacy perspective.

BACKGROUND: Cancer patients are being exposed to antineoplastic drugs more frequently and for longer periods, resulting in a higher risk of hypersensitivity reactions. The aim of this study was to assess the pharmaceutical time and direct cost of drug allergy explorations following immediate hypersensitivity reactions to antineoplastic agents. METHODS: A micro-costing method was used to collect data on consumption of human and material resources for allergy exploration preparations. The monetisation was carried out on the basis of prices and hourly wage costs applied in 2018. The number and type of allergy explorations prepared by the pharmacy as well as nature of antineoplastic drugs tested, and the number of culprit drugs reintroductions were collected. RESULTS: Almost 1.5 h is required to realise allergy tests for one patient including pharmacist time for prescription analysis and pharmacy technician's time for tests preparation. The mean manufacturing cost of these tests is estimated at €62.87 (€57.82-65.49) per culprit drug for one patient. Programming patients according to culprit drugs tested allows rationalising healthcare provider time and increasing efficiency. From January 2010 to December 2018, 277 patients were tested and 490 allergy explorations were performed, corresponding to more than 5000 preparations. Mostly, the culprit drug could be reintroduced (n = 383, 78.2%) allowing patients to receive the best possible treatment. CONCLUSION: Management of hypersensitivity reactions is constantly progressing, as it contributes to improving patient care in oncology. This activity is time-consuming for the pharmacy team but allows patients with previous hypersensitivity reaction to continue effective treatment.

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.

Effect of Diet in Chronic Spontaneous Urticaria: A Systematic Review.

Strategies for diets in chronic spontaneous urticaria (CSU) are controversial. This systematic review assessed the interest in diet for managing CSU. We searched for original reports in MEDLINE, EMBASE, CENTRAL and LILACS. Among the 278 reports screened, 20 were included, involving 1,734 patients. Reports described 3 types of systematic diet: pseudoallergen-free diet (n = 1,555 patients), low-histamine diet (n = 223) and diet without fish products (n = 47), which induced complete remission in 4.8%, 11.7% and 10.6% of patients, respectively, and partial remission in 37.0%, 43.9% and 4.3%. Eight reports described personalized exclusion diets (66 patients) adapted to symptoms/allergological test results and led to complete remission in 74.6% of patients, although the diagnosis of CSU was doubtful. No comparative randomized studies of diets were available. The only randomized studies were based on oral provocation tests with the suspected responsible diet. Population and outcomes were heterogeneous. In conclusion, there is evidence for the benefit of diets in CSU only in individual patients with clinical symptoms. However, the level of evidence is low for the benefit of systematic diets in CSU because systematic double-blind controlled trials of diet are lacking.

Therapeutic patient education improves knowledge and skills for patients with chronic spontaneous urticaria.

Therapeutic patient education (TPE) allows patients to better understand their disease and cope with treatment. TPE programmes have not yet been evaluated for chronic spontaneous urticaria (CSU). To investigate the cognitive and behavioural impact of TPE on CSU patients. CSU patients were selected who completed a TPE programme. A pre-post comparison was performed using a skill/knowledge questionnaire, based on six educational objectives, before and after the intervention. The course of CSU was also analysed, according to daily hive count and itch intensity. All of the 61 enrolled patients improved their knowledge and skills following TPE, with greatest improvement in itch management and use of alternatives to scratching. CSU activity was reduced at the end of the programme in 60% of patients. TPE improves knowledge and skills for CSU patients. Further research is needed to demonstrate the positive impact of TPE on CSU activity.

Efficacy and Safety of Infliximab Tolerance Induction in Patients with Inflammatory Bowel Diseases who Experienced Acute Infusion Reactions.

BACKGROUND AND AIMS: One of the reasons for the failure of infliximab (IFX) is immediate hypersensitivity reactions (IHR). We aimed to report the efficacy and safety of a tolerance induction protocol in inflammatory bowel diseases (IBD) patients who had previously experienced IHR during IFX infusions. PATIENTS AND METHODS: We reported all cases of IBD patients who had previously experienced IHR due to IFX and who were submitted to a standardized protocol of tolerance induction to IFX from 2010 to 2015. RESULTS: IHR occurred in a majority of patients (69%) during the first 3 infusions and for half of them after a period of IFX withdrawn. Skin prick tests were negative and only 2 intradermal tests were positive. Basophil activation tests and antidrug antibody measurements were performed in 8 out of 16 patients and were positive in 3 and 4 patients respectively. Induction of tolerance was successful in 69% of patients and IFX was pursued with clinical efficacy > 1 year in 7 patients (44%). Allergologic investigations were not predictive of tolerance induction success. CONCLUSION: A majority of IHR to IFX infusions occurred during the beginning or restarting of treatment and was related to a nonallergic hypersensitivity. Induction of tolerance to IFX is feasible and effective and may safely allow retreatment of IFX in almost 70% of IBD patients.

Chronic spontaneous urticaria in children - a systematic review on interventions and comorbidities.

BACKGROUND: Chronic spontaneous urticaria (CSU) is not frequent in children. Management guidelines have been developed for adults and randomized controlled trials (RCTs) included teenagers aged 12-18, but data for children under age 12 are limited. We performed a systematic review to assess comorbidities in children <12 years old with CSU and the efficacy and safety of treatments. METHODS: We searched for original articles of epidemiologic and treatment data in children <12 years old with CSU that were published from 2005 to July 2016 in MEDLINE, EMBASE, CENTRAL, and LILACS. Article selection and data extraction were performed in duplicate. RESULTS: Our systematic review included 9 reports on epidemiologic data (633 children). Five comorbidities and laboratory anomalies associated with CSU found were atopy (28.1%), positive autologous serum skin test (36.8%), thyroid biologic anomalies (6.4%) and detectable antinuclear antigen (10.4%), seroprevalence for Helicobacter pylori (21.1%), low vitamin D level (69.1%), and psychiatric disorders (70.4%). Only one study allowed for comparison with a control group. Our review included 10 studies (322 children), describing 5 different drug families, mostly H1-antihistamines (n = 297). One randomized controlled study compared single-dose rupatadine with single-dose desloratadine and placebo. Cyclosporine was effective and had no adverse effects in 18 children. Omalizumab, montelukast, and cefuroxime were reported in very small series (5, 1, and 1 patients). CONCLUSIONS: H1-antihistamines are effective for CSU in children <12 years old, with reassuring safety data at licensed doses. Cyclosporine seems effective, but the level of evidence is low.