Shiga toxin‐associated hemolytic uremic syndrome (STEC‐HUS) is associated with significant mortality and morbidity. Case fatalities are often associated with severe neurological involvement in children and advanced age in adults but specific treatment is currently unavailable. Plasma exchange (PE) could theoretically enable removal of Shiga toxins, pro‐inflammatory cytokines, and prothrombotic factors and has been used in deteriorating patients with STEC‐HUS but the efficacy remains uncertain. In order to assess efficacy of PE in STEC‐HUS, a literature review was performed. PubMed, Web of Science, Embase, and LiLACS were searched for reports describing the outcomes of patients with STEC‐HUS treated with PE and 16 reports were included. Reports ranged from case reports to cohort studies and one case–control study with the largest study population coming from the 2011 German STEC‐HUS outbreak. Outcomes were variable but seemed to point towards lower case fatality rates in the elderly and improved outcomes in children with STEC‐HUS, treated with PE early in the course. However studies were mostly of low quality with risk of observation bias and confounding. Currently no definitive answers concerning the efficacy of PE in STEC‐HUS can be given, highlighting the need for well performed randomized controlled trials.

A 3-month-old boy presented with failure to thrive and a history of a prenatally detected unilateral hydroureteronephrosis which was confirmed after birth. His growth and developmental milestones had been normal during the first 2 months but in the third month his appetite was poor with reduced intake but no vomiting. At presentation, his temperature was normal, there was mild dehydration and there was weight loss (his weight had decreased by 270 g in the past month). Haemoglobin was 11.9 g/dL, total white cell count 20.2 × 10/L (7-15) [neutrophils 30% (39-75) and lymphocytes 61% (16-47)], platelets 702 × 10/L (150-450), BUN12.1 mmol/L (2.1-16.1), serum creatinine 35.4 μmol/L (15.0-37.1), sodium 126 mmol/L (135-144), potassium 6.8 mmol/L (3.6-4.8), chloride 88 mmol/L (98-106) and bicarbonate 14 mmol/L (19-24). Intravenous rehydration with sodium chloride 0.9% solution was commenced and he was transferred to the paediatric intensive care unit. A salt-wasting syndrome was suspected and a differential diagnosis included adrenal insufficiency, pseudohypoaldosteronism and congenital adrenal hyperplasia (owing to 21-hydroxylase deficiency). Urinalysis confirmed a urinary tract infection. Serum aldosterone was 3608 ng/dL (3.7-43.2), plasma renin activity > 38.9 pmol/L (<0.85), random cortisol 459 nmol/L (74-289), adrenocorticotropic hormone (ACTH) 6.01 pmol/L (1.32-6.60) and 17-hydroxyprogesterone 4.01 nmol/L (<3.2). Treatment of the urinary tract infection was followed by normalisation of serum electrolytes and other biochemical abnormalities, return of appetite and normal growth, which confirmed the diagnosis of transient pseudohypoaldosteronsim (TPHA). TPHA is discussed and insight provided to enable early recognition and adequate treatment of this rare clinical entity.