Diagnosis and Treatment of Difficult Nephrotic Syndrome

Albumin infusion alongside diuretics is reserved for children with resistant, severe oedema, generalised swelling causing respiratory or genital distress, or an albumin level around 1.5 or below. A child with just mild eyelid swelling from a relapse does not need diuretics: the relapse itself is treated first, typically with steroids and review every third day, and diuretics are added only if the swelling is not settling, partly because prolonged oedema is an excellent medium for secondary bacterial infection, including spontaneous bacterial peritonitis.

It follows the same mechanism as the rest of the oedema: low albumin causes fluid to shift into dependent spaces in the body, and the right lung is affected somewhat more often than the left. The underlying pathophysiology is hypoalbuminaemia driving fluid out of the vascular space into surrounding tissue, known as third spacing.

Abdominal pain in these children usually has a few overlapping causes: spontaneous bacterial peritonitis, treated with a third-generation cephalosporin, since a diagnostic ascitic tap is no longer recommended because the puncture site tends to leak and add a further infection risk; stretching of the liver capsule; and simply the physical discomfort of a child's abdomen suddenly distending, similar in scale to a late-term pregnancy, which makes walking and daily activity very difficult. Swelling of the intestines themselves also contributes to the pain and can cause diarrhoea.

Children who present soon after a relapse with only mild eyelid swelling respond to steroids alone and do not need diuretics. Children with full-body swelling, low albumin around 1.5 or below, and no response to oral diuretics need albumin infusion alongside diuretics, and are identifiable clinically by severe swelling causing breathing difficulty or genital oedema. Oral diuretics alone are for children who have been on steroids for 10 to 14 days, are heading into remission, but still have uncomfortable, spreading facial swelling.

Monitoring has to cover growth, charting height and weight and adjusting diet if the child is faltering, immunisation status, since immunity is lower on immunosuppressants and needs support, and the eyes, since cataracts and raised intraocular pressure can develop and fundus changes can reflect hypertension. Blood pressure itself needs care to interpret correctly: parents are asked to record home readings at different times of day along with the child's position and activity, since white-coat hypertension can otherwise be mistaken for the real thing. Longer term, children with frequent relapses can also develop hair loss, hypothyroidism and visible skin changes, all of which need specific follow-up.

A subset of children with nephrotic syndrome relapse frequently, become dependent on steroids to stay in remission, or never respond to steroids at all. These patterns only become clear over months of following a child's disease, not from a single visit.

Whether a child is an infrequent relapser, a frequent relapser, steroid-dependent, or steroid-resistant is defined by how their disease behaves over repeated episodes, not by any single test result at diagnosis.