Statistics from Altmetric.com
Editor,—Acute appendicitis is the most common surgical emergency in children, estimated to occur at a rate of 4 per 100 per annum. Its prompt diagnosis is important because the risk of perforation increases with time, occurring in 10% of patients by 24 hours and up to 50% by 48 hours.1 The technique for renal transplantation in children is similar to that in adults, the extraperitoneal placement of the kidney being sited in the right (or more rarely left) iliac fossa (RIF). The renal artery is anastomosed to the common iliac artery or aorta and the renal vein to the external iliac vein or inferior vena cava. The differential diagnosis of RIF pain in this group of children will therefore include conditions frequently affecting the graft: acute obstruction, urinary tract infection, and acute allograft rejection. This may result in a delay in diagnosis of acute RIF pain secondary to other causes.
A 10 year old boy was transferred from his local hospital where he presented with a history of suspected gastroenteritis and severe hypo-osmolar dehydration. He had received a cadaveric renal transplant eight months previously. He was in renal failure from pseudo-prune-belly syndrome (grossly dilated urinary tract but good rectus muscles),2 and extensive urological surgery had been undertaken in the past. Four days before presentation, he developed a pyrexial illness associated with headache, diarrhoea, and vomiting. There was notable right sided abdominal and suprapubic pain. After 12 hours at the local hospital he was transferred with a presumptive diagnosis of acute allograft rejection.
On examination he was febrile (38.5°C) and his blood pressure was 110 mm Hg systolic. He had a tachycardia and a capillary refill time of two seconds. His abdomen was diffusely tender with localisation over the graft in the RIF with guarding. A rectal examination was not done. Haemoglobin was 102 g/l; white cell count 22 000 (90% neutrophils); plasma sodium 113 mmol/l, plasma creatinine concentration 78 μmol/l compared to a baseline of 60 μmol/l. His urine microscopy was negative for leucocytes and bacteria.
Following resuscitation with intravenous fluids he underwent urgent laparotomy; a perforated appendix was resected. There was subhepatic and subphrenic collections of free pus. He was given 50 ml/kg body weight colloid and blood during surgery, and postoperatively he required ventilation for 12 hours. He was kept nil by mouth for six days and received immunosuppression and nutrition intravenously. Intravenous antibiotics were continued for one week. He was allowed home on the ninth postoperative day with normal renal function.
There are few reports of appendicitis in kidney transplant recipients. Eight patients, all of them adults, have been reported in the literature to date.3-6 Appendicitis in kidney transplant recipients is an important diagnosis to make promptly because of the risk of perforation. A delay in the diagnosis of acute appendicitis in preschool children has been highlighted in a recent review.7 Of 132 children treated for acute appendicitis, 36 (27%) had an uncomplicated illness, 63 (48%) had perforation, and 29 (22%) had an appendix mass. The mean duration of symptoms before admission was 39 hours in the uncomplicated group, 53 hours for perforation, and 82 hours for appendix mass. A misdiagnosis was made in 53 cases (40%) leading to a delay in management.
Renal transplantation is a relatively uncommon clinical subject for the general paediatrician, who will be unfamiliar with many of the acute problems presenting in a transplant patient. It is uncommon for acute allograft rejection, obstruction, or urinary tract infection to cause peritonism. However, acute appendicitis can occur in the transplant recipient just as in the general population; any delay in diagnosis may complicate the illness.