COVID-19 vaccine booster shots may cause delayed-onset urticaria

Sixteen patients at a private dermatology practice in Denmark developed delayed-onset urticaria after receiving COVID-19 vaccine boosters between February and June 2022, according to a letter published in Clinical and Translational Allergy.

Patients also developed symptomatic dermographism after receiving the Pfizer-BioNTech and Moderna boosters, according to Jakob Lillemoen Drivenes, MD, of Vestfold Hospital Trust in Tonsberg, Norway, and colleagues.

“In private dermatology practice, we noticed an increasing number of patients with newly developed or aggravated urticarial reactions and symptomatic dermographism following booster vaccination,” Drivenes told Healio. “This led to a discussion on a Danish mailing list for dermatologists about a possible relation to COVID booster vaccines, especially Moderna. After this discussion, we started to prospectively collect patients.”

The patients included 10 women and six men (median age, 33 years; range, 20-73). Thirteen of them developed inducible urticaria and/or spontaneous urticaria after receiving the booster, even though they had no previous medical history of urticaria.

Also, three patients with existing urticaria experienced exacerbations, and two patients developed symptomatic dermographism. One patient later developed cutaneous lymphocytic vasculitis.

All these symptoms developed between 1 day and 3 weeks (median, 14 days) after the booster was administered. Most patients experienced severe symptoms. Six required acute doctor visits, and four were admitted to the ED.

“What was characteristic and caught our attention to this patient group was the highly symptomatic dermographism, which was the main complaint by the patients (eg, bothersome itchy dermographism), and also patients referring that they could write on their skin,” Drivenes said.

Clinicians used high-dose antihistamines to treat all 16 patients. Four patients also received systemic corticosteroids and five received further treatment with omalizumab (Xolair; Genentech, Novartis).

The researchers attributed these reactions to the booster as they did not find any other plausible causes via medical histories and routine blood tests, in addition to more extensive blood testing and clinical workup for many of the patients.

The urticaria and dermographism had resolved for four of the patients after a median of 3 months. Also, four patients were in clinical remission and receiving antihistamines and omalizumab. However, despite antihistamines and omalizumab for symptom control, seven patients remained symptomatic, with one patient lost to follow-up.

Seventy-five percent of patients in this study received the Moderna vaccine and although this was interesting, Drivenes said, the numbers were too low to draw conclusions.

The researchers could not elucidate the mechanism behind these reactions, but they suggested that their timing does not indicate any type 1 IgE mediation. Symptom onset, the researchers continued, seemed to correlate with the peak responses of the humoral and cellular immunity that vaccination induces, with the production of histamine-releasing autoantibodies another potential mechanism behind these reactions.

“Although true reactions to mRNA vaccines are rare, it is important to identify and distinguish between immediate hypersensitivity reactions and delayed urticarial reactions, as the immediate hypersensitivity reactions prompts postponing the subsequent vaccine dose,” Drivenes said.

Also, Drivenes said it was important to note that treatment for patients with this distinct clinical picture would be similar to treatment for chronic spontaneous urticaria and that these symptoms are not a contraindication for future vaccination.

“Doctors can help guide care when patients have concerns about a prior vaccine reaction with employment of shared decision-making and by performing deep phenotyping and providing risk stratification and recommendations based on current available information,” Drivenes said.

Due to increasing literature and research about this subject, Drivenes continued, Danish Patient Compensation has begun investigating cases of delated urticarial reactions after COVID-19 vaccination.

“More research is needed to better understand the cause of reactions in patients who develop delayed-onset urticaria and symptomatic dermographism following COVID-19 booster vaccinations,” Drivenes said.

For more information:

Jakob Lillemoen Drivenes, MD, can be reached at jakobdrivenes@hotmail.com.