ABSTRACT
Background: Polyethylene glycol (PEG) is being used for the first time as an excipient in mRNA vaccines against SARS-CoV- 2 containing PEG 2000, highlighting it as a potential cause of anaphylaxis. We aim to report clinical cases of severe allergy to PEG and furthermore to assess the usefulness of skin tests (ST) performed with the commercial extract PEG 1500 for the allergy work-up of patients with suspected allergy to SARS-CoV- 2 vaccines. Method(s): We evaluated 126 patients with moderate to high risk of allergy to SARS-CoV- 2 vaccination referred to our Allergy Department from March to December 2021. ST were performed with extract PEG 1500 (Roxall), using the following methodology: prick tests with 0.1%, 1% and 10% concentrations, with readings at 30 minutes (according to manufacturer's instructions);if negative, intradermal tests (IDT) were performed with the 1/10 dilution (0.01%), except in cases of anaphylaxis, where dilutions 1/1000 and 1/100 were used (adapted from previous publication using PEG 20000). Immediate IDT readings were made at 30 minutes and delayed readings at 24 hours. The same protocol was applied to 5 healthy controls who received PEGylated vaccines. Result(s): We present 6 cases of severe PEG allergy: one near-fatal anaphylaxis after glucocorticoid injection containing PEG 3350 and five systemic allergic reactions after mRNA vaccine containing PEG 2000 (Pfizer-BioNTech or Moderna). All patients had positive immediate IDT using PEG 1500 allowing the diagnosis and the selection of vaccine without PEG. All of them were negative to polysorbate 80. One patient developed anaphylaxis following IDT 0.01%. In the remaining 120 patients, the ST using PEG 1500 were negative in immediate and delayed reading of IDT. Seven patients were positive to polysorbate 80. All healthy controls had negative ST using PEG 1500. Conclusion(s): To our knowledge this is the first case series describing the allergy work-up testing with commercial extract PEG 1500 in the scope of SARS-CoV- 2 vaccination. ST using extract PEG 1500 revealed to be a useful tool for the diagnosis of PEG allergy, since it allowed confirming six cases of severe PEG allergy, contraindicating the further administration of PEGylated vaccines. It also allowed allergy exclusion in one hundred cases that took afterwards SARS-CoV- 2 vaccines containing PEG 2000. Moreover, healthy controls had negative IDT demonstrating the reliability of the proposed procedure. Investigation should only be conducted in a specialized drug allergy centre.
ABSTRACT
Summary: Background. Polyethylene glycol (PEG) is being used for first time as an excipient for mRNA anti-SARS-CoV-2 vaccines containing-PEG2000, highlighting it as a potential cause of anaphylaxis. Objective. To assess the usefulness of skin tests using PEG1500 extract in patients with suspected allergy to SARS-CoV-2 vaccines. Methods. We evaluated 126 patients with moderate-high risk of allergy to SARS-CoV-2 vaccines referred to our department from March-December 2021. Skin tests were performed with PEG1500 extract (Roxall), using a stepwise approach, with readings at 30 minutes: prick tests with 0.1%, 1% and 10% concentrations; if negative, intradermal tests with 0.0001%, 0.001% and 0.01% concentrations. The same protocol was applied to 5 healthy controls. Results. Six patients had positive immediate intradermal tests with PEG1500, all with severe PEG allergy: one with a near-fatal anaphylaxis after glucocorticoid injection containing-PEG3350 and five with systemic allergic reactions after mRNA vaccines containing-PEG2000 (Pfizer-BioNTech or Moderna). One patient developed anaphylaxis during intradermal test. These six patients were negative to polysorbate 80. The remaining 120 patients had negative tests to PEG1500; seven had positive tests to polysorbate 80. All controls had negative tests. Conclusions. To our knowledge this is the first study describing the allergy work-up testing with PEG1500 commercial extract in the scope of SARS-CoV-2 vaccination. The algorithm designed for skin tests revealed to be a useful tool. Severe PEG allergy was diagnosed in 5% of patients, contraindicating PEG-containing vaccines. PEG allergy was excluded in one hundred patients that afterwards took SARS-CoV-2 vaccines containing-PEG2000. Investigation should be conducted in specialized drug allergy centres.
ABSTRACT
As the COVID-19 pandemic gradually comes under control, the members of the Spanish Contact Dermatitis and Skin Allergy Research Group (GEIDAC) have drawn up a proposed list of the requirements, limitations, and conditioning factors affecting the resumption of work in contact dermatitis units. The assumption is that the severe acute respiratory syndrome coronavirus 2 is still circulating and that occasional or seasonal outbreaks will occur. They recommend that the first step should be to assess how many patch tests each clinic can handle and review the waiting list to prioritize cases according to disease severity and urgency. Digital technologies can, where possible, be used to send and receive the documentation necessary for the patch test (information, instructions, informed consent, etc.). If the necessary infrastructure is available, patients can be offered the option of a remote initial consultation. Likewise, in selected cases, the patch test results can be read in a virtual visit using photographs taken by the patient or a video visit can be scheduled to allow the physician to evaluate the site of application remotely. These measures will reduce the number of face-to-face visits required, but will not affect the time spent on each case, which must be scheduled in the normal manner. All of these recommendations are suggestions and should be adapted to the needs and possibilities of each health centre.
ABSTRACT
As the COVID-19 pandemic gradually comes under control, the members of the Spanish Contact Dermatitis and Skin Allergy Research Group (GEIDAC) have drawn up a proposed list of the requirements, limitations, and conditioning factors affecting the resumption of work in contact dermatitis units. The assumption is that the severe acute respiratory syndrome coronavirus2 is still circulating and that occasional or seasonal outbreaks will occur. They recommend that the first step should be to assess how many patch tests each clinic can handle and review the waiting list to prioritize cases according to disease severity and urgency. Digital technologies can, where possible, be used to send and receive the documentation necessary for the patch test (information, instructions, informed consent, etc.). If the necessary infrastructure is available, patients can be offered the option of a remote initial consultation. Likewise, in selected cases, the patch test results can be read in a virtual visit using photographs taken by the patient or a video visit can be scheduled to allow the physician to evaluate the site of application remotely. These measures will reduce the number of face-to-face visits required, but will not affect the time spent on each case, which must be scheduled in the normal manner. All of these recommendations are suggestions and should be adapted to the needs and possibilities of each health centre.