Henoch-Schonlein purpura in children. Influence of age on the incidence of nephritis and arthritis

To assess the epidemiological, clinical, and laboratory findings in children affected with Henoch-Schonlein purpura [HSP], and to analyze the influence of age on the incidence of nephritis and arthritis. This is a retrospective study of the case records of all patients admitted to Prince Rahmah Hospital, Irbid, Jordan with HSP from September 1997 to December 2006, and to King Abdullah University Hospital, Irbid, Jordan from August 2005 to December 2006. The clinical manifestations included purpura in 100% of the 68 patients, arthritis in 75%, and nephritis in 29%. The incidence of nephritis varied according to the age of patients. It occurred in 19% of children less than 5 years of age, and in 67% of children 10 years of age and above. Henoch-Schonlein purpura nephritis was mild in all age groups. The incidence of arthritis also varied according to the age of patients. Arthritis occurred in 56% of children less than 5 years of age, and in 89% of children 10 years of age and above. The incidence of nephritis and arthritis in children affected with HSP is age related. Older children have a higher incidence of nephritis and arthritis, while younger children have a lower incidence of nephritis and arthritis. Renal involvement was mild during the acute phase of the disease in all age groups