This film is inspired by Cabin Fever (2002) and The Evil Dead (1981).
Although very exaggerated, this film is based on a real human disease called hay fever. an allergy caused by pollen or dust in which the mucous membranes of the eyes and nose are inflamed, causing running at the nose and watery eyes. Symptom onset is often within minutes following allergen exposure, and can affect sleep and the ability to work or study. It can be severe if not treated.
Director Henry Richardson is a sufferer of hay fever and decided to make this film to show people who don't suffer from it what it feels like and how awful it is.