tldr:

  We present two cases of COVID-19 vaccine-induced pityriasis rosea. Skin lesions appeared in a 49-year-old female 8 days after the first dose of the BNT162b2 mRNA vaccine and in a 53-year-old male 7 days after the second dose of the same vaccine.
  ...
  Her rash gradually improved and at follow-up, 4 weeks later, it had resolved completely.
  ...
  The itching was self-limiting and therefore the patient did not receive any antihistamines. His rash resolved completely over a period of 4 weeks.