A revision of the present concept of the named collagenosis in the pediatric age, supported of the experience of the Pediatrics Department at the Barcelona University is exposed. A casuist of 109 cases of the Schoenlein-Henoch syndrome, 55 observations of juvenile rheumatoid arthritis and 16 pediatric patients affected of classic collagenosis is included. A classification of the collagenosis in pediatrics, discriminating classic forms and other process and in both groups the entities of known etiology, and the unknown ones, that are majority, been considered as collagenosis in the strict sense is offered.