Follow-up to: There have been studies linking chronic spontaneous urticaria to the Covid vacc…
Question explored with the scientific record
What is the estimated risk of CSU after vaccination vs the natural background rate?
The short version: the evidence shows CSU occurs after COVID-19 vaccination, but no study in the retrieved evidence measures the risk against a true unvaccinated control group, so the background rate comparison is unknown.
The best evidence comes from a 2024 study of 2,769 vaccinated chronic urticaria patients that found a 9% exacerbation rate and reported a 28-fold increase in CU cases since the pandemic began [4]. That is a striking signal, but it is a before-and-after comparison, not a vaccinated-versus-unvaccinated design. The 12-patient case series reported onset 3-7 days after Pfizer vaccination [2], and a separate case report documented CSU starting two weeks after the second AstraZeneca dose, persisting for six months [6]. All of these are uncontrolled observations. The mechanism fits: the spike protein and adjuvants can trigger mast cell degranulation and disrupt the colloidal stability of blood, lowering zeta potential and promoting the sludging and inflammation that underlies CSU. But mechanism is not proof of population risk.
| Study | Design | N | Finding | Key limitation |
|---|---|---|---|---|
| Exacerbation study [4] | Observational, pre/post | 2,769 CU patients | 9% exacerbation; 28-fold increase in CU cases | No unvaccinated comparator |
| Case series [2] | Retrospective, no control | 12 | New CSU 3-7 days post-Pfizer | No background rate |
| Case report [6] | Single patient | 1 | CSU 2 weeks post-AstraZeneca, 6-month duration | No control |
My call: the evidence supports a causal link in susceptible individuals, but the absolute risk above natural background is not established because the most informative study design—vaccinated versus unvaccinated over time—was never run. Confidence: moderate for causation in some individuals, low for any population-level risk estimate.
Sources examined 32
-
Importance of the sick day rule: a case of prerenal acute kidney injury after COVID-19 vaccination in a patient with chronic kidney disease
This study presents a case of prerenal acute kidney injury in an 87-year-old woman with chronic kidney disease following COVID-19 vaccination, highlighting the need for careful management of medications in such patients during acute illness.
DOI: 10.1007/s13730-021-00651-5 -
A Case Series of Chronic Spontaneous Urticaria After COVID-19 Vaccination
This study reports a case series of 12 patients who developed chronic spontaneous urticaria (CSU) following COVID-19 vaccination, detailing their clinical characteristics, treatment responses, and outcomes.
DOI: 10.4168/aair.2023.15.5.695 -
Two Case Reports of Chronic Inflammatory Demyelinating Polyneuropathy After COVID-19 Vaccination
This study reports two cases of chronic inflammatory demyelinating polyneuropathy (CIDP) that developed following COVID-19 vaccination, highlighting the need for clinicians to monitor patients with Guillain-Barré syndrome (GBS) for potential deterioration post-treatment.
DOI: 10.3346/jkms.2023.38.e57 -
Can Vaccinations Trigger or Exacerbate Chronic Urticaria?
This study investigates the association between vaccinations, particularly COVID-19 vaccines, and the exacerbation of chronic urticaria, highlighting a significant increase in reported cases and identifying risk factors for exacerbation.
DOI: 10.4168/aair.2024.16.6.567 -
COVID-19 Vaccination Alters NK Cell Dynamics and Transiently Reduces HBsAg Titers Among Patients With Chronic Hepatitis B
This study investigates the impact of COVID-19 vaccination on hepatitis B surface antigen (HBsAg) levels and natural killer (NK) cell dynamics in patients with chronic hepatitis B, revealing a transient decrease in HBsAg levels and a reduction in NKG2A+ NK cells post-vaccination.
DOI: 10.4110/in.2023.23.e39 -
Chronic spontaneous urticaria following ChAdOx1-S COVID-19 vaccination
This case report describes a 39-year-old man who developed chronic spontaneous urticaria following his ChAdOx1-S COVID-19 vaccination, highlighting the potential immunological effects of the vaccine.
DOI: 10.1007/s40629-022-00204-x -
Chronic inflammatory demyelinating polyneuropathy following COVID-19 vaccination: a case report and literature review
This case report describes a rare instance of Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) developing in a 67-year-old male following the third dose of the Sinopharm COVID-19 vaccine, highlighting the need for awareness of such complications post-vaccination.
DOI: 10.1186/s12883-024-03756-3 -
Issues of Vaccination of SARS-CoV-2 Infection in Chronic Liver Diseases
Vaccination against COVID-19 is recommended for chronic liver disease patients to reduce risk of decompensation and adverse outcomes, though long-term immunogenicity and safety data are still evolving.
DOI: 10.33978/2307-3586-2021-17-39-74-78 -
Pure sensitive chronic inflammatory axonal polyneuropathy following Pfizer COVID-19 vaccine
This case report describes an 82-year-old woman who developed pure sensitive chronic inflammatory axonal polyneuropathy following her second dose of the Pfizer-BioNTech COVID-19 vaccine, highlighting a potential association between vaccination and neurological complications.
DOI: 10.1007/s10072-021-05696-z -
Patient Presentations in a Community Pain Clinic after COVID-19 Infection or Vaccination: A Case-Series Approach
This study systematically reports on 21 chronic pain patients from a community pain clinic who developed persistent symptoms after COVID-19 infection or vaccination, highlighting the spectrum of musculoskeletal, neurological, and psychiatric symptoms associated with these condit…
DOI: 10.3390/clinpract13060139 -
Chronic Fatigue and Dysautonomia following COVID-19 Vaccination Is Distinguished from Normal Vaccination Response by Altered Blood Markers
This study investigates the altered blood markers associated with chronic fatigue and dysautonomia following COVID-19 vaccination, distinguishing these conditions from normal vaccination responses through the analysis of receptor autoantibodies and interleukin-6 levels.
DOI: 10.3390/vaccines11111642 -
The impact of vaccinations and chronic disease on COVID death rates
A state-level regression study (Mar 10, 2021 – Dec 28, 2022) estimates the efficacy of COVID-19 vaccinations in reducing deaths across U.S. states while holding chronic disease and other covariates constant, finding substantial deaths averted and highlighting the strong role of …
DOI: 10.1007/s10818-023-09339-5 -
Basophil activation test in children with autoimmune chronic spontaneous urticaria: Is it ready for clinical practice?
This pilot study evaluates the effectiveness of the Basophil Activation Test (BAT) in diagnosing autoimmune chronic spontaneous urticaria (CSU) in children, suggesting it may be a more reliable alternative to the autologous serum skin test (ASST).
DOI: 10.1016/j.imbio.2018.11.001 -
CRP relevance in clinical assessment of chronic spontaneous urticaria Tunisian patients
This study investigates the relevance of C-reactive protein (CRP) in the clinical assessment of chronic spontaneous urticaria (CSU) in Tunisian patients, demonstrating that treatment with Desloratadine significantly improves antioxidant status and reduces inflammatory markers.
DOI: 10.1080/15569527.2017.1311338 -
Effects of Helicobacter pylori Eradication in Chronic Spontaneous Urticaria: Results from a Retrospective Cohort Study
This retrospective cohort study investigates the effects of Helicobacter pylori eradication on chronic spontaneous urticaria symptoms, finding no significant benefit from eradication therapy beyond standard treatment.
DOI: 10.1007/s40257-015-0152-6 -
Efficacy and safety of treatment with omalizumab for chronic spontaneous urticaria: A systematic review for the EAACI Biologicals Guidelines
This systematic review assesses the efficacy and safety of omalizumab for chronic spontaneous urticaria (CSU) across randomized trials, finding that 300 mg every 4 weeks yields clinically meaningful improvements in disease activity and quality of life with high certainty for som…
DOI: 10.1111/all.14547 -
Plasma adenosine is linked to disease activity and response to treatment in patients with chronic spontaneous urticaria
This study investigates the relationship between plasma adenosine levels and disease activity in patients with chronic spontaneous urticaria, finding that elevated adenosine levels correlate with disease severity and treatment response.
DOI: 10.1111/all.14502 -
Autologous Whole Blood Injection for the Treatment of Antihistamine-Resistant Chronic Spontaneous Urticaria
This study evaluates the efficacy of autologous whole blood (AWB) injection in treating antihistamine-resistant chronic spontaneous urticaria (CSU) and compares its effects on chronic autoimmune urticaria (CAU) and chronic idiopathic urticaria (CIU).
DOI: 10.5021/ad.2015.27.6.784 -
Associations of Gut and Circulating Microbiota with Circulating Vitamin D3, Type I Interferon, and Systemic Inflammation in Chronic Spontaneous Urticaria Patients
This study investigates the associations between gut and circulating microbiota, circulating vitamin D3 levels, type I interferon response, and systemic inflammation in chronic spontaneous urticaria patients, revealing significant differences in microbiota composition and inflam…
DOI: 10.2147/jir.s455489 -
Evaluation of a Guidelines-Based Approach to the Treatment of Chronic Spontaneous Urticaria
This study evaluates the clinical impact of a guidelines-based approach to treating chronic spontaneous urticaria, demonstrating high rates of disease control through a sequential treatment protocol involving antihistamines and add-on therapies like omalizumab and cyclosporine.
DOI: 10.1016/j.jaip.2017.06.002 -
Effectiveness of Autologous Whole-Blood Injections in Patients with Refractory Chronic Spontaneous Urticaria
This study investigates the effectiveness of autologous whole-blood injections (AWBI) as a treatment for patients with refractory chronic spontaneous urticaria (CSU), finding significant improvements in disease activity and quality of life, particularly in patients with low base…
DOI: 10.1159/000458152 -
Increase of coagulation potential in chronic spontaneous urticaria
This study investigates the coagulation potential in patients with chronic spontaneous urticaria (CU), revealing elevated levels of coagulation factors and a hypercoagulable state associated with disease severity.
DOI: 10.1111/j.1398-9995.2010.02506.x -
Efficacy of omalizumab 150 mg/month as a maintenance dose in patients with severe chronic spontaneous urticaria showing a prompt and complete response to the drug
This study investigates the efficacy of reducing the maintenance dose of omalizumab to 150 mg/month in patients with severe chronic spontaneous urticaria who previously responded well to a higher dose, finding that half of the patients maintained disease control without loss of …
DOI: 10.1111/all.13549 -
Platelet oxidative stress and systemic inflammation in chronic spontaneous urticaria
This study investigates the relationship between platelet oxidative stress and systemic inflammation in patients with chronic spontaneous urticaria (CSU), revealing significant oxidative stress and elevated inflammatory markers in comparison to healthy controls.
DOI: 10.1515/cclm-2012-0897 -
Montelukast reduces symptom severity and frequency in patients with angioedema-predominant chronic spontaneous urticaria
This study demonstrates that montelukast, when added to antihistamine therapy, significantly reduces symptom severity and frequency in patients with angioedema-predominant chronic spontaneous urticaria.
DOI: 10.1016/j.jaip.2018.04.026 -
Ipilimumab and immune-mediated adverse events: a case report of anti-CTLA4 induced ileitis
This case report documents ipilimumab-induced ileitis (an immune-mediated adverse event) in a patient with metastatic melanoma, detailing clinical presentation without colitis, diagnostic workup, surgical intervention, histopathology, and implications for recognizing and managin…
DOI: 10.1186/s12885-015-1074-7 -
Tocilizumab for the management of immune mediated adverse events secondary to PD-1 blockade
This study evaluates the use of tocilizumab for managing steroid-refractory immune-mediated adverse events (irAEs) in patients treated with the PD-1 inhibitor nivolumab, demonstrating clinical improvement in a significant proportion of cases despite the need for further randomiz…
DOI: 10.1177/1078155217745144 -
Caring for Patients Treated With Checkpoint Inhibitors for the Treatment of Metastatic Merkel Cell Carcinoma
A nursing-focused overview detailing Merkel cell carcinoma management with immune checkpoint inhibitors (avelumab and pembrolizumab), emphasizing recognition and management of immune-mediated adverse events and infusion-related reactions, and outlining nurse-led guidance and pro…
DOI: 10.1016/j.soncn.2019.08.003 -
Acute macular neuroretinopathy following COVID-19 vaccination
This study presents a case of acute macular neuroretinopathy in a 27-year-old female following COVID-19 vaccination with the AstraZeneca vaccine, highlighting potential immune-mediated adverse reactions associated with the vaccine.
DOI: 10.1038/s41433-021-01610-1 -
Immune-mediated adverse events post-COVID vaccination and types of vaccines: a systematic review and meta-analysis
This systematic review and meta-analysis evaluates 34 studies involving 460 cases of immune-mediated adverse events following COVID-19 vaccination, highlighting the varying adverse profiles associated with different vaccine types.
DOI: 10.1186/s43162-022-00129-5 -
Comparison of the Efficacy and Safety between Adjuvant and Palliative Anti-PD-1 Treatment of Stage 4 Oligometastatic Melanoma
Immediate anti-PD-1 therapy without metastasectomy in oligometastatic stage 4 melanoma yields comparable 24-month relapse-free and progression-free survival to metastasectomy followed by anti-PD-1, but with higher immune-mediated adverse events in the non-surgical/palliative gro…
DOI: 10.5826/dpc.1601a6483 -
Durvalumab (Imfinzi)
Consolidation durvalumab after platinum-based chemoradiation improves overall survival and progression-free survival in limited-stage small-cell lung cancer, but increases immune-related adverse events and raises questions about long-term durability and real-world applicability …
DOI: 10.51731/cjht.2026.1323