Level 2 - Renal, Dermatology Flashcards
Definition of HUS?
- Triad of acute renal failure, microangiopathic haemolytic anaemia (schistocytes, burr cells) and thrombocytopenia
Damage in HUS?
- Endothelial damage to glomerular capillaries
Pathology in typical HUS? How is it acquired?
o Secondary to GI infection with E.coli 0157 (produces verocytotoxin which localises in endothelial cells of kidney and causes intravascular thrombogenesis)
o Coagulation cascade activated which consumes platelets and MHA results from damaged to red blood cells when they circulate through microcirculation
o Acquired through contact with farm animals, eating uncooked beef or less often, Shigella
Pathology in atypical HUS?
o Not-diarrhoea associated and often familial
When does HUS usually present?
- Typical HUS usually in <3 year olds
- Commonest cause of AKI, peaks in summer months
Risk factors for HUS?
o Rural populations
o Warmer summer months
o 6 months – 5 years
o Contact with farm animals
Symptoms and signs of typical HUS?
o Follows a prodrome of diarrhoea which turns bloody
o Often fever, abdominal pain, vomiting
o Haemorrhagic Colitis → Haemoglobinuria → Oliguria → CNS signs → Encephalopathy → Coma
DDx of HUS?
- Other causes of diarrhoea – gastroenteritis, appendicitis, IBD
- DIC
- HELLP syndrome (Haemolysis, Elevated Liver enzymes, Low Platelet count)
- TTP
What is seen on blood tests in HUS? What other tests are needed?
- Bloods
o FBC (raised WCC, low platelets, haemolytic anaemia, thrombocytopenia) and blood film (fragmented red cells), CRP, clotting
o U&Es (AKI), LFTs
o High LDH
- Stool microscopy and culture
- Urine microscopy and culture
Management of HUS?
- Inform local Health Protection Unit
- Early supportive treatment
o Appropriate fluid and electrolyte management
o Antihypertensive therapy
- Dialysis when required
Complications of HUS?
Intestinal perforation, pancreatitis, severe colitis, altered mental state, seizures, AKI, CKD, Haematuria, hypertension and proteinuria
Why does HUS need follow up?
- Follow-up as may be persistent proteinuria and hypertension
Definition of nephrotic syndrome?
- Clinical syndrome defined as:
o Proteinuria
o Oedema
o hypoalbuminemia
Pathology of nephrotic syndrome?
- Increased permeability of serum protein through the damaged basement membrane in the renal glomerulus
How is nephrotic syndrome classified?
- Classified as steroid sensitive, steroid resistant or steroid dependent
Aetiology of nephrotic syndrome?
- 90% cause is unknown
Primary glomerular causes of nephrotic syndrome?
Minimal change disease – 85% in children
Focal segmental glomerulonephritis (FSGN)
Membranous glomerular disease
Membranoproliferative glomerulonephritis
Secondary glomerular causes in nephrotic syndrome?
Infection – HIV, HepB/C, syphilis, malaria
SLE, HSP, Lupus
Diabetes
Alport’s syndrome
Malignancies
Toxins (snake bites, bee stings) and heavy metals
Symptoms and signs of nephrotic syndrome?
- Periorbital oedema, leg/ankle oedema, ascites and breathlessness
- Oliguria
- Proteinuria, oedema, hypoalbuminemia
- Dyslipidaemia, abnormalities in coagulation/fibrinolysis, reduced renal function
Investigations performed in nephrotic syndrome? and why?
- Urine dipstick
o Check for protein & microscopic haematuria
- Urine MSU
o Microscopy, culture and sensitivities to exclude UTI
- Bloods
o FBC, CRP, ESR, U&E’s (creatinine, low albumin)
o Complement levels
o Autoimmune screen
o HepB/C screen
- CXR and renal USS
- Renal biopsy
General management of nephrotic syndrome?
- Sodium and fluid restriction
- High-dose diuretics
Management of steroid sensitive nephrotic syndrome?
o Oral prednisolone for 4 weeks then wean over 4 months
If steroid toxicity, use cyclophosphamide
o Pneumococcal and influenza vaccination
Management of steroid-resistent nephrotic syndrome?
o Management of oedema with diuretics, salt restriction and ACE inhibitors (enalapril)
What is Steven Johnson Syndrome? Range of severity?
- Immune-complex-mediated hypersensitivity disorder
- Ranges from mild skin and mucous membrane lesions to a severe, sometimes fatal systemic illness: toxic epidermal necrolysis (TEN)
Spectrum of disorders in SJS? Classification?
- SJS, SJS/TEN overlap and TEN form a spectrum of severe cutaneous adverse reactions (SCAR) that can be differentiated by the degree of skin and mucous membrane involvement
- The classification is based on the percentage of body surface area detached
Epidemiology of SJS?
- Incidence is 2-3 cases/million population/year
- More common in individuals with HIV
- Females > males
- Most 10-30 years old