The chemotactic response of peripheral blood polymorphonuclear leukocytes (PMNs) to N-formyl-methionyl-leucyl-phenylalanine was determined in four groups of persons (I) 19 patients with pustulosis palmoplantaris (PPP) and skeletal disorder (pustulotic arthro-osteitis); (II) 15 patients with a similar anterior chest wall involvement, but no PPP; (III) 9 patients with PPP, but without skeletal involvement, and (IV) 69 healthy adults (controls). The chemotactic activity of PMNs was found to be significantly increased in groups I–III, and patients with a similar osteoarthropathy, but no PPP compared with the controls. Furthermore the patients with pustulotic arthrosteitis had enhanced chemotactic activity compared with the patients with PPP only. This indicates that both skeletal involvement and PPP are somehow related to the function of PMNs. Colchicine was found of benefit in 2 of 3 group I, and in 6 group II patients, and it normalized their PMN chemotaxi