Synopsis
Treat FSGS as a histological pattern with multiple causes, distinguish primary podocytopathy from adaptive, genetic and secondary disease, and avoid harmful immunosuppression when it cannot help.
- Focal segmental glomerulosclerosis is a biopsy lesion, not one disease: focal means only some glomeruli and segmental means only part of an affected tuft is scarred.
- Primary FSGS is a circulating-factor podocytopathy typically causing abrupt nephrotic syndrome with diffuse foot-process effacement after secondary causes are excluded.
- Secondary adaptive FSGS follows reduced nephron mass, obesity, reflux, sickle disease or longstanding hyperfiltration and often produces proteinuria without profound hypoalbuminaemia.
Key red flags
A rapid creatinine rise with heavy proteinuria and collapsing capillary tufts may be associated with viral infection, medicine exposure or high-risk genotype and needs urgent cause assessment.
Investigation priorities
Quantify total and albumin protein, identify haematuria and establish response baselines.
Management branches
Native kidney pathology identifies a focal segmental sclerotic lesion.
- Confirm full nephrotic syndrome, review electron-microscopy effacement and adequacy, and ask renal pathology to describe variant, activity and chronicity.
- Search systematically for reduced nephron mass, obesity, reflux, infection, medicine or substance exposure, family history, early onset and syndromic features.
Key medicines
PrednisoloneSpecialist high-dose daily or alternate-day treatment continues until remission, intolerance or the maximum 16-week response period.
Tacrolimus or ciclosporinUse a trough-guided specialist regimen for at least six months in steroid-resistant primary disease before judging response.