Cutaneous Reactions and the COVID-19 Vaccine
Clinical trials for both vaccines noted the potential for cutaneous reactions after vaccination, but these reactions were not fully characterized.
An article published in the Journal of the American Academy of Dermatology in April 2021 presented findings from a provider-facing registry that tracked the morphology and timing of cutaneous reactions after mRNA COVID-19 vaccination from December 2020 to February 2021.2 The median age of the patients in the registry was 44 years, with the majority of the patients being female (90%), White (78%) and from the United States (98%). 414 cases of cutaneous reactions were reported, with 343 reported after Moderna vaccination and the remaining 71 cases reported after Pfizer vaccination.2
The most common cutaneous eruptions seen after Moderna vaccination included delayed large-local reactions, local injection site reactions, urticaria, morbilliform eruptions, and erythromelalgia. The delayed large-local reaction, often been referred to as “COVID arm,” is a phenomenon specifically linked to Moderna vaccinations and presented as erythema, pruritus, induration, and tenderness 2-12 days after vaccination.3 The most common cutaneous manifestations reported after Pfizer vaccinations included urticaria, local injection-site reactions, and morbilliform eruptions.2 Less common reports of other cutaneous findings with both vaccines included nine reports of swelling at the site of cosmetic fillers, which has been a subject of much interest in both media and patient populations.
The median time from first vaccination to onset of cutaneous symptoms was seven days, while the median time from second-dose vaccination to cutaneous symptoms onset was much shorter, occurring at day one. Reported cases of urticaria or angioedema were not immediate in onset; all came after 1 day or more. In addition, no cases of anaphylaxis were reported with either vaccine dose in the registry. In all patients who experienced a cutaneous reaction, no severe sequelae were identified and patients responded well to supportive therapy such as topical steroids, oral antihistamines, and/or pain relievers.2
Numerous hypotheses have been proposed regarding the etiology of these cutaneous reactions. Of note, it is proposed that the delayed large-local reaction associated with the Moderna vaccination is a possible delayed-type or T-cell mediated hypersensitivity. Biopsies taken from affected areas have shown superficial perivascular, perifollicular lymphocytic infiltrates with rare eosinophils and scattered mast cells, supportive of this theory.4 Also, both vaccines contain a well-known allergen, polyethylene glycol, which has been previously identified as a possible culprit for hypersensitivity reactions. Lastly, cases of facial swelling in patients with cosmetic fillers were reported with both vaccines, which likely represent a delayed-hypersensitivity reaction to the filler, with the vaccine acting as an immunologic trigger.1
The overall findings in this study support that cutaneous reactions to COVID-19 vaccines are generally self-limited, minor, and should not deter vaccination. However, providers should be aware of these reactions and appropriately counsel their patients when recommending vaccination. Additional and ongoing reporting and documentation of cutaneous reactions with all available vaccines, including Ad26.COV2.S by Janssen/J&J, is encouraged to assist in further elucidation of the incidence and development of these reactions.
1. Jackson LA, Anderson EJ, Rouphael NG, et al. An mRNA Vaccine Against SARS-CoV-2 – Preliminary Report.N Engl J Med. 2020;383:1920-1931.8
2. McMahon DE, Amerson E, Rosenbach M, et al. Cutaneous reactions reported after Moderna and Pfizer COVID-19 vaccination: A registry-based study of 414 cases. J Am Acad Dermatol. 2021 Apr 7:S0190-9622(21)00658-7.
3. Johnston MS, Galan A, Watsky KL, et al. Delayed Localized Hypersensitivity Reactions to the Moderna COVID-19 Vaccine: A Case Series. JAMA Dermatol. Published online May 12, 2021.
4. Blumenthal KG, Freeman EE, Saff RR, et al. Delayed Large Local Reactions to mRNA-1273 Vaccine against SARS-CoV-2. N Engl J Med. 2021 Apr 1;384(13):1273-1277.
Eileen Cheever MPAS, PA-C, resides with her husband Aaron in Lunenburg, Massachusetts. She works at Clearview Dermatology in Leominster, Massachusetts. In her spare time, she enjoys cheering on her favorite Boston sports teams and exploring the outdoors with her husband and their dog, Jasta.