Sweet, working in Plymouth in 1964, described a disease with four features: fever; leukocytosis; acute, tender, red plaques; and a papillary dermal infiltrate of neutrophils.
More recently, it has also been shown that not only bacteria but also pathogenic fungi such as Candida albicans induces neutrophils to form NETs that capture and kill C. albicans hyphal as well as yeast-form cells.
Diagnosis is by aspiration (giving a turbid, non-viscous fluid), Gram stain and culture of fluid from the joint, as well as tell-tale signs in laboratory testing (such as a highly elevated neutrophils (approx. 90%), ESR or CRP).