Oral food challenges are usually undertaken in hospital, although for some adults, guided oral food challenge can be safely undertaken at home. Oral food challenges are distinct from supervised feeding or introduction of allergenic foods such as nuts, into the diets of high-risk infants. Oral food challenges are often used as a diagnostic tool but can also be useful to assess tolerance to milk, egg, nuts and other foods in older children and adults. They often have a positive impact on quality of life, irrespective of the outcome.