oligoarthritis oligoarthritis oligoarthritis (from greek oligos - 'few') is defined as arthritis affecting two to four joints during the first six months of disease. oligoarthritisspecialtyrheumatology types two subcategories are recognized: persistent oligoarthritis: affecting not more than 4 joints throughout the disease course extended oligoarthritis: affecting a total of more than 4 joints after the first 6 months of disease notes petty re, southwood tr, manners p, et al. (february 2004). "international league of associations for rheumatology classification of juvenile idiopathic arthritis: second revision, edmonton, 2001". j. rheumatol. 31 (2): 390–2. pmid 14760812. rapini, ronald p.; bolognia, jean l.; jorizzo, joseph l. (2007). dermatology: 2-volume set. st. louis: mosby. isbn 978-1-4160-2999-1.