Cutaneous reactions may occur after messenger RNA (mRNA)-based coronavirus disease 2019 (COVID-19) vaccination. In the Moderna vaccine (mRNA-1273) clinical trial, immediate injection-site reactions were reported in 84.2% of participants after the first dose, and delayed injection-site reactions (on or after day 8) were reported in 0.8% of participants after the first dose and 0.2% after the second dose. Injection-site reactions after the third (booster) injection have also been reported.

In the largest registry-based study of cutaneous COVID-19 vaccine reactions to date, the majority of reported reactions to mRNA COVID-19 vaccination occurred with the Moderna vaccine (83%) as compared with the Pfizer-BioNTech vaccine (BNT162b2, Comirnaty [17%]). Individuals who experienced reactions were predominantly female (90%), White (78%), and middle-aged.

Reported reactions include:

• Early local reactions, including erythema, edema, and induration with or without pain or pruritus at the vaccine site.
• Delayed large local reaction, referred to as "COVID arm," which is a localized erythematous plaque surrounding the injection site that occurs an average of 7 days after the first vaccine dose with resolution usually within 11 days. The etiology of delayed large local reactions is unknown but is hypothesized to represent a delayed hypersensitivity reaction to the excipient polyethylene glycol. Delayed reactions are reported to be less severe with the second vaccine dose, and onset may be within 2-3 days. Recurrence after the vaccine booster has also been reported.
• Urticarial reaction: Seen with both mRNA vaccines. The onset is more than 24 hours postvaccination, and the mean duration in one study was a week.
• Morbilliform rash: Reported after the Pfizer-BioNTech and the AstraZeneca vaccines. Onset is around 4 days postvaccination, and the eruption lasts approximately 10 days.
• Pityriasis rosea-like (PR-like) eruption: Onset is around day 6, and this may last for up to 4 weeks. It has been postulated that the PR-like eruption may be secondary to HHV-6/7 reactivation stimulated by the vaccine.
• Papulovesicular eruption: Seen with both mRNA vaccines. Onset is approximately 6-7 days postvaccination, and this eruption may last up to 3 weeks.
  • Vaccine-related eruption of papules and plaques (V-REPP) has been introduced as a term to describe a spectrum of generalized cutaneous reactions to COVID-19 vaccines. Clinical appearance includes a papulosquamous eruption with scale (mild), PR-like eruption (moderate), and a papulovesicular eruption (severe). V-REPP generally appears on the trunk and extremities, but moderate and severe cases can involve the head, neck, and face.
• Purpuric eruptions, including leukocytoclastic vasculitis: Seen following Moderna and AstraZeneca vaccines.

Other reported reactions to mRNA vaccines include pernio / chilblains, erythema multiforme-like eruptions, erythromelalgia, new-onset bullous pemphigoid or bullous pemphigoid-like eruptions, a facial pustular neutrophilic eruption, symmetric drug-related intertriginous and flexural exanthema, erythema nodosum, and delayed inflammatory reactions to hyaluronic acid dermal fillers. Eruptive lichen planus after vaccination has also been reported. There have been rare reports of lymphomatoid reactions after vaccination with the Pfizer-BioNTech COVID-19 vaccine. Two cases of new-onset sclerotic skin disease (scleroderma-myositis overlap, eosinophilic fasciitis) following receipt of mRNA COVID-19 vaccines in patients with prior rheumatic cutaneous disease have been reported. New-onset vitiligo has also been reported in patients after receiving mRNA vaccines.

Severe cutaneous eruptions, including acute generalized exanthematous pustulosis (AGEP) and Stevens-Johnson syndrome (SJS) / toxic epidermal necrolysis (TEN), have been exceedingly rarely reported.

Additionally, a number of cases of herpes zoster developing shortly after vaccination, especially after the first dose, with mRNA vaccines almost exclusively, has been reported. Herpes simplex virus reactivation has also been reported. 

Cutaneous reactions appear to be self-limited but may be treated with topical corticosteroids, oral antihistamines, and/or pain-relieving medications. Blistering eruptions may be more persistent.

Patients may develop cutaneous reactions after the first dose, second dose, or both doses of an mRNA COVID-19 vaccine. Reactions to the second dose tend to be less severe and develop faster. There have been no reported cutaneous serious adverse events after the first or second dose. Patients should be reassured that development of a cutaneous reaction to the first dose is not a contraindication to receiving the second dose.

Compared with mRNA COVID-19 vaccines, cutaneous reactions have been less commonly reported after adenoviral vector COVID-19 vaccines. However, vaccine-induced immune thrombotic thrombocytopenia (VITT) has been reported in response to the Johnson & Johnson (Janssen) and the AstraZeneca COVID-19 vaccines. VITT may present with a purpuric rash 1-2 weeks after receiving an adenoviral vector COVID-19 vaccine. There have been rare reports of Guillain-Barré syndrome occurring about 2 weeks after having the Johnson & Johnson (Janssen) COVID-19 vaccine. Most cases have occurred in men aged 50 years and older. There is a report of drug reaction with eosinophilia and systemic symptoms (DRESS) following vaccination with the AstraZeneca COVID-19 vaccine.