Chronic Spontaneous Urticaria (CSU) Following COVID-19 Vaccine:
Preliminary Observations and Self-Tracking Data
Isaac Gerg, firstname.lastname@example.org
Information Processing & Algorithms Laboratory (iPAL)
Dept. of Electrical Engineering & Computer Science (EECS)
Pennsylvania State University (PSU)
•I developed urticaria (CSU) after getting COVID-19 vaccine booster (2 doses + booster).
•Others are developing this condition under similar circumstances.
Anecdote: My dermatologist reported seeing a lot of urticaria in January 2022.
Online Facebook group “Chronic Spontaneous Urticaria After COVID-19 Vaccine Support Group, ” 6k members.
•Literature reports this phenomenon: , , , , , , , .
.A. R. Wolfson et al. “Urticaria 12 Days After COVID-19 mRNA Booster Vaccination”. In: JAMA (Apr. 2022). issn: 0098-7484. doi:10.1001/jama.2022.5247. eprint:
.Chronic urticaria for 4 months after the ﬁrst dose of Pﬁzer mRNA COVID-19 vaccine.https://www.aaaai.org/Allergist-Resources/Ask-the- Expert/Answers/2021/chronicurticaria.
.M. Smee et al. “COVID-19 Vaccine Induced Flares of Chronic Spontaneous Urticaria: A Case Series”. In: Journal of Allergy and Clinical Immunology 149.2 (2022), AB180.
.J. Thomas et al. “Chronic Spontaneous Urticaria After COVID-19 Vaccine”. In: Cureus 13.9 (2021).
.C. Alﬂen et al. “Two cases of well controlled chronic spontaneous urticaria triggered by the moderna COVID-19 vaccine”. In: Allergy & Rhinology 12 (2021), p. 21526567211026271.
.C. A. e. a. Thomas J Thomas G. Chronic Spontaneous Urticaria After COVID-19 Vaccine.
https://www.cureus.com/articles/69363-chronic- spontaneous-urticaria- after-covid- 19-vaccine. Accessed: 2022-04-14.
.M. S. Johnston et al. “Delayed localized hypersensitivity reactions to the Moderna COVID-19 vaccine: a case series”. In: JAMA dermatology 157.6 (2021), pp. 716–720.
.S. G. Brooks et al. “Chronic Spontaneous Urticaria Triggered by the AstraZeneca/Oxford COVID-19 Vaccine with Achieved Remission: A Case Rep ort”. In: Allergy & Rhinology 13 (2022),
Preliminary ObservationsIy 1/16Iy
Is Urticaria from COVID-19 Vaccine Reported in the VAERS Database?
•If urticaria patients don’t show a “signal” in the reporting system, we can’t get our problem addressed.
•YES, we see urticaria post-COVID19-vaccine in VAERS database.
•Overview of Vaccine Adverse Event Reporting System (VAERS)
Maintained by US Department Health and Human Services (HHS)
Established in 1990
Co-managed by Centers for Disease Control and Prevention (CDC) and the U.S. Food and Drug Administration
Anyone can report. However, “Healthcare professionals are required to report certain adverse events and vaccine
manufacturers are required to report all adverse events” - https://vaers.hhs.gov/about.html
•We considered VAERS records from 2021-2022
Start with 873,253 records.
Filter for COVID19 vaccine: 810,687 (93%)
Filter by symptom type “urticaria”, “wheals”, “hives”: 25,486 (3%)
VAERS DatabaseIy 2/16Iy
Onset of Symptoms by Vaccination Date
Figure 1: (Left) 2D Histogram of pertinent cases by date of vaccine and number of days until symptom onset. We
categorize this data into three cohorts: early (2021-01 thru 2021-05), late (2021-11 thru 2022-01), and overall (everyone).
(Right) Histogram of early (blue) and late (orange) cohorts.
•The late cohort has a mode at 10-11 days where as the early cohort has one at 7-8 days.
•Early and late cohorts have diﬀerent symptom proﬁle which could indicate booster-related eﬀect.
•In the late cohort, we see urticaria-like symptoms start 10 days post vaccine (similar to what is reported in
online FB group as I will show).
VAERS DatabaseIy 3/16Iy
VAERS Reports by Vaccine Manufacturer
(a) Overall (b) Early (c) Late
Figure 2: Vaccine manufacturer distribution by cohort.
•Why Moderna vaccine increase in late cohort? Trying to ﬁnd overall numbers of each vaccine administered
VAERS DatabaseIy 4/16Iy
Onset of Symptoms by Vaccination Date - Non-COVID19 Vaccines
Figure 3: (Left) Scatterplot of pertinent cases by date of vaccine and number of days until symptom onset. We use the
same three cohorts previously deﬁned: early (2021-01 thru 2021-05), late (2021-11 thru 2022-01), and overall (everyone).
(Right) Histogram of early (blue) and late (orange) cohorts. Diﬃcult to tell if any correlation with COVID-19 vaccine.
Further statistical testing warranted but sample size is very small.
•We see a similar pattern in the late cohort as the COVID-19 vaccination results.
•Too few data points to check for signiﬁcance. Could be reporting error (truly COVID-19 vaccine
administered but incorrect vaccine selected when reporting)? Time of year eﬀect?
VAERS DatabaseIy 5/16Iy
Shift from Acute Urticaria to Chronic Spontaneous Urticaria?
•Majority of literature reports focus on immediate onset and quick resolution of symptoms, but this becomes
a chronic problem for some.
•Are these the 10 day post-vaccine urticaria patients we saw in VAERS which now have progressed to CSU?
•Facebook group “Chronic Spontaneous Urticaria After COVID-19 Vaccine Support Group”
Started around December 15, 2021
As of April 2022 6k+ members
Informal surveys of members show median onset of symptoms 11 days after second shot or booster,
As of March 2022, GP and Allergists treating primarily with 2nd generation anti-histamine but with double and
quadruple doses, augmenting with H2antagonists.
•Performed several “polls” in the Facebook group to collect data on cohort in late April 2022.
Following slides show results.
Shift from Urticaria to CSU?Iy 6/16Iy
FB Group - Members
Shift from Urticaria to CSU?Iy 7/16Iy
FB Group - Country of Origin
•Likely biased since USA likely uses FB more than other countries and group language is English (there is a
German language forum also!).
Shift from Urticaria to CSU?Iy 8/16Iy
FB Group - Gender & Age
Shift from Urticaria to CSU?Iy 9/16Iy
FB Group - Vaccine Manufacturer & Symptom Onset after Vaccine
•Similar to VAERS
•Trying to located overall numbers of each vaccine administered.
Shift from Urticaria to CSU?Iy 10/16Iy
FB Group - Patient Blood Type
•p = 0.02 of being USA blood type distribution (unknown how many participants are from USA due to FB
Shift from Urticaria to CSU?Iy 11/16Iy
FB Group - Pharmaceutical Treatments
•Most patients use multiple pharmaceutical treatments.
•Diﬃcult to obtain Ndue to FB poll limitations.
Shift from Urticaria to CSU?Iy 12/16Iy
FB Group - Symptom Change from Exercise
•Most report that exercise results in no change of symptoms.
Shift from Urticaria to CSU?Iy 13/16Iy
My Self-Tracking Results
•Majority of bloodwork normal, C-reactive protein (CRP) ↓, .
•SARS Cov2 Ab above reporting threshold. Wife is 100.0; same vaccination schedule as myself. Several FB
members noted outside of detection limits (i.e. high levels) also. Suggestive of a diagnostic test?
•Elevated IgE (cutoﬀ 87 kU/L), IL-10 (cutoﬀ 2.8 pg/mL)
.H. M. Akca et al. “Correlation of urticaria activity score in chronic spontaneous urticaria with serum C-reactive protein level and neutrophil/lymphocyte ratio”. In: Dermatologic Therapy 33.6
.I. Puxeddu et al. “Biomarkers in chronic spontaneous urticaria: current targets and clinical implications”. In: Journal of asthma and allergy 12 (2019), p. 285.
Looking for Collaborators
Consider donating to Dr. Blumenthal’s Vaccine Allergy Research
Join the Citizen Scientists for the Understanding of CSU Following COVID19 Vaccination (CSU2FCV) as
a CSU suﬀerer or control. https://www.facebook.com/groups/1145587869597781.
Next StepsIy 15/16Iy
•Open Humans Community: Dr. Bastian Greshake Tzovaras, Dr. Mad Price Ball, Richard Sprague
•Members of Chronic Spontaneous Urticaria After COVID-19 Vaccine Support Group
(https://www.facebook.com/groups/442950024085956) and Chronic Spontaneous Urticaria After
COVID-19 Vaccine Science Group (https://www.facebook.com/groups/1392535707859728)
•Stryx Biotech - Dr. Rick Roy
Additional Self-Tracking Resources
•Serimmune - “Our goal is to understand diﬀerences in personal immune response to infection by the
COVID-19 virus, SARS-CoV-2.” (https://serimmune.com/covid19study/)
•COVID-19 Vaccine Allergy Case Registry (https://allergyresearch.massgeneral.org)
•FB CSU Support Group Surveys
Age - https://www.facebook.com/groups/442950024085956/permalink/521733762874248
Exercise - https://www.facebook.com/groups/442950024085956/permalink/522258149488476
Pharmaceutical Treatments -
Gender - https://www.facebook.com/groups/442950024085956/posts/521677552879869
Manufacturer - https://www.facebook.com/groups/442950024085956/posts/521683846212573
Blood Type - https://www.facebook.com/groups/442950024085956/posts/520551982992426
Country - https://www.facebook.com/groups/442950024085956/posts/521683116212646
How can patients self-track their condition?
Good overview of serum tests 
Many US states don’t require MD order to get serum tests
Anti-FcϵRI or Anti-IgE autoantibodies ↑and IgE ↓=⇒more severe
C-reactive protein level and neutrophil/lymphocyte ratio 
Total IgE 
CRP ↑, D-dimer ↑in H1non-responders 
•Urticaria Activity Score (UAS7) 
urticaria-score- sheet.pdf From Puxeddu, et al. (2019)
.Puxeddu et al., “Biomarkers in chronic spontaneous urticaria: current targets and clinical implications”.
.R. Sabroe et al. “Chronic idiopathic urticaria: comparison of the clinical features of patients with and without anti-FcϵRI or anti-IgE autoantibodies”. In: Journal of the American Academy of
Dermatology 40.3 (1999), pp. 443–450.
.Akca et al., “Correlation of urticaria activity score in chronic spontaneous urticaria with serum C-reactive protein level and neutrophil/lymphocyte ratio”.
.S. Altrichter et al. “Total IgE as a marker for chronic spontaneous urticaria”. In: Allergy, Asthma & Immunology Research 13.2 (2021), p. 206.
.L. de Montjoye et al. “Correlations between disease activity, autoimmunity and biological parameters in patients with chronic spontaneous urticaria”. In: Eur Ann Allergy Clin Immunol 53.2
(2020), pp. 55–66.
.T. Hawro et al. “The Urticaria Activity Score—validity, reliability, and responsiveness”. In: The Journal of Allergy and Clinical Immunology: In Practice 6.4 (2018), pp. 1185–1190.
•Vitamin D , 
.I. Oguz Topal et al. “Does replacement of vitamin D reduce the symptom scores and improve quality of life in patients with chronic urticaria?” In: Journal of Dermatological Treatment 27.2
(2016), pp. 163–166.
.R. Rasool et al. “Chronic urticaria merits serum vitamin D evaluation and supplementation; a randomized case control study”. In: World Allergy Organization Journal 8.1 (2015), pp. 1–10.
Vaccine Approval Dates
EUA, ages 12-15, Aug 23, 2021. ages 16+ Dec 11, 2020
•Moderna COVID-19 Vaccine
EUA. Dec 18, 2020, ages 18+ . Approved Ages 18+ Jan 31, 2022