Many sorts of eruptions have been reported to follow vaccination against smallpox. In 1942 Bloch1 reported 123 postvaccinial rashes after 500,000 persons were vaccinated in Glasgow because of a smallpox epidemic there. These eruptions usually appeared 7 to 11 days after a well-marked positive primary vaccination. Most of these eruptions were diagnosed as papular urticaria or erythema multiforme, with a scattering of other conditions appearing. None of these, however, were diagnosed as pityriasis rosea. Sulzberger2 reported that he has never seen a case of pityriasis rosea following smallpox vaccination. Cohen3 has not observed such an occurrence in Great Britain. Marshall,4 in a recent extensive study in South Africa, does not mention vaccination preceding pityriasis rosea.
Last winter a senior medical student at Vanderbilt University developed pityriasis rosea following a routine vaccination. After this, the lesions of pityriasis rosea became vesicular and were con