Skin lesions after Covid 19 vaccination

In a non-interventional retrospective study of the Clinic and Polyclinic for Dermatology and Allergology of the Technical University of Munich, it could be shown within a large patient collective by specialist dermatological assessment of the skin changes and the course that the reactions were not limited to certain vaccines, were of non-allergic origin and could be divided into known reaction patterns.

A total of 83 patients were included who presented to the clinic because of skin lesions occurring within 30 days of Covid-19 vaccination (mean age, 47.3 years ± 18.3 years; 71.1% female). More than one skin reaction was reported by 10 patients (8 women, 2 men). Most patients received BNT162b2 (57; 68.7%) before the initial onset of skin lesions, followed by mRNA-1273 (12; 14.5%), ChAdOx1 (11; 13.3%), Ad26.COV2.S (2; 2.4%), and CVnCoV (CureVac, clinically tested in Germany) (1; 1.2%).

Time of occurrence

Skin changes were classified according to reaction patterns (Fig. 1). 62.0% of the skin reactions occurred initially after the first vaccination, 28.3% only after the second and 9.8% after the third vaccination. In the latter cases, the first and/or second vaccination had been well tolerated. 72.8% of skin reactions manifested within the first week after vaccination, with 16.3% occurring on the day of vaccination and 21.7% occurring in the second week after vaccination. The median time to onset of reactions was 3 days. Immediate hypersensitivity reactions such as urticaria occurred mainly in the first week with a median delay of one day, while chronic inflammatory skin conditions tended to occur later with a median delay of 7 days (p=0.02).

Clinical course

Treatment was necessary in 83.9% of cases. Antihistamines (56.3%), topical (46.3%), and systemic glucocorticosteroids (35.0%) were used. In 19.4% of cases, inpatient treatment was required. In 77.4% of cases, the skin changes were only temporary and completely resolved during the course, while in 22.6% of cases they had not completely resolved at the last presentation. No recurrence of skin reactions occurred in 51.2% after follow-up vaccination, although four of the patients had received premedication (prophylactic use of antihistamines or 10 mg prednisolone at the time of the second vaccination). In 48.8% (21/43), the previously reported skin reactions also occurred in the first week after follow-up vaccination. Immediate hypersensitivity reactions (34 vaccine reactions: 26 urticaria, 4 flushing, 3 pruritus, 1 angioedema) also accounted for the majority of reactions in this patient cohort. Diagnostic skin tests were performed in 15 patients for allergological clarification. These were all negative; there was no evidence of an underlying allergy of the immediate type as the causative trigger of the skin reactions.

Conclusion

The recurrence of the same skin lesion at subsequent vaccination in about half of the patients argues against a purely coincidental temporal association of the two events. The skin reactions did not recur with each subsequent vaccination, suggesting that vaccination may trigger skin reactions primarily in those patients who are predisposed to such reactions or skin diseases. The majority of reactions were mild and self-limiting, with symptomatic treatment usually required.

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