This volume on Rarer Arthropathies, part of the series "Rare Diseases of the Immune System" aims to fill a gap in the literature by informing and updating clinicians on the unusual and uncommon forms of arthritis and related musculoskeletal conditions. It will be a valuable go-to resource for clinicians to support them in differential diagnosis, in particular when facing unusual presentations. Nineteen chapters written by experts have covered a wide range of these conditions, providing first rate information on topics yet lacking adequate coverage; from Palindromic Rheumatism to SAPHO Syndrome and other chronic immune-mediated conditions, while also including arthritis in leprosy, tuberculosis and chikungunya.