A 10-year-old girl with no previous history developed a sore throat without fever 4 weeks prior to admission. Antibiotics were not given and the symptoms subsided within 4-5 days. About 2 weeks later, she developed palpebral oedema and decreased urine output followed by low-grade fever during a 5-day vacation in Bali. She did not receive any medical treatment except for some antipyretic drug. Two days later, she was referred to our hospital because of fever and facial swelling.On admission, physical examination revealed a body temperature of 39.8°C, pulse rate 118/min, respiratory rate 38/min and blood pressure of 132/77 mm Hg. She also developed an erythematous rash over the neck, trunk and proximal regions of all limbs. The rash was evanescent, not itching and became prominent with the development of fever, with some raised areas and a serpiginous border (Fig. 1). Her throat showed congestion and tonsillar enlargement. Cardiac examination revealed a grade 2/6 systolic murmur over the apex of the heart. Laboratory investigations revealed the following: haemoglobin 10.6 g/ dl, elevated ESR at 30 mm/h, normal total and differential white blood cell counts, normal blood urea nitrogen and serum creatinine. Urinalysis showed proteinuria (+++), 25-30 RBCs/hpf and abundant dysmorphic RBCs. The 24-h urine collection showed a protein loss of 2.838 g/day. Creatinine clearance was 44 ml/min. Blood and urine cultures were negative. Serum complement levels revealed decreased C3 (14.6 mg/dl,normal 79-152 mg/dl) and normal C4 (26.4 mg/dl). Rheumatoid factor was negative and the anti-double strain DNA antibody was negative. A chest X-ray film revealed cardiomegaly and an ECG showed poor R wave progression. Echocardiography showed mild mitral, aortic valve regurgitations and tiny tricuspid, pulmonary valve insufficiencies. Moreover, pericardial effusion was also present. Fig. 2 Mildly enlarged glomeruli showing a picture of mesangial cell proliferation, scattered polymorphonuclear infiltration and the regeneration of tubules and RBC in the lumen. Haematoxylin and eosin, ·400Fig. 1 Skin rash over the patient's anterior abdominal and chest regions. The serpiginous border with central clear appearance (arrow) is evident Eur J Pediatr (2003) 162: 655-657