Orf virus has a worldwide distribution among sheep and goats. The hypersensitivity reaction erythema multiforme (EM) is a known complication of orf infection in humans; however, its occurrence is poorly understood and has not been extensively reviewed. We present two unrelated cases of orf-associated EM, and a review of the literature, highlighting important clinical, epidemiological and immunological aspects of this condition. Orf and its associated complications can occur in rural areas, as well as urban settings, where it is less well-known, through religious or cultural practices involving animal slaughter. Obtaining a history of animal exposures from patients with lesions suspicious for orf and secondary skin eruptions can guide diagnosis and identification of the inciting immune stimulus. Determining the pathophysiology and relative contribution of host and viral factors contributing to EM and other orf-associated hypersensitivity reactions could facilitate the identification of risk factors and inform treatment decisions.

Hepatitis E virus (HEV) infection results in hepatitis E, an acute and self-limited disease. The virus is transmitted in a faecal–oral manner and is a major cause of viral hepatitis in much of the developing world, where it causes rampant sporadic infections and large epidemics. A curious feature of hepatitis E is the unusually high rates of mortality that are observed in pregnant women, in whom the disease is exacerbated by the development of fulminant liver disease. In the absence of viable in vitro propagation systems, several geographical isolates of HEV have been maintained in vivo in nonhuman primates and, subsequently, the viral genome has been cloned and sequenced. HEV has been classified provisionally into a separate family known as the HEV-like viruses, which has at least four recognised genotypes, but has only a single serotype. The viral genome is a positive-stranded (+)RNA of ~7.5 kb and encodes at least three proteins. Open reading frame 1 (ORF1) encodes the viral nonstructural polyprotein, which has domains that are homologous to some of the replication and processing enzymes found in other +RNA viruses. The HEV protein itself remains poorly characterised. The protein encoded by open reading frame 2 (ORF2) is the major HEV capsid protein, and the protein encoded by open reading frame 3 (ORF3) appears to be involved in virus–host interactions. Several questions related to the biology, epidemiology and pathogenesis of HEV remain unanswered; the progress of a few of these is reviewed here.

A case of orf affecting the pinna is discussed. This is an unusual presentation of aninfection that is common in farming communities.

At the initial presentation the diagnosis was not suspected, the management therefore was inappropriate and probably gave rise to the secondary infection that ensued. The history described is classical.

Orf affecting the external auditory canal has been reported once, but orf affecting the pinna has not been described before.