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
Aetiology of SJS?
- Approximately 75% of SJS/TEN are caused by medications and 25% by infections and ‘other’ causes
What medications cause SJS?
- Allopurinol, carbamazepine, sulphonamides, antiviral agents, phenobarbital, phenytoin, valproic acid, lamotrigine
What infections causes SJS?
- HSV, EBV, HIV, influenza, bacterial, fungal
Symptoms and signs of SJS?
- Starts with a URTI
- May be associated with fever, sore throat, chills, headache, arthralgia, vomiting and diarrhoea and malaise
- Mucocutaneous lesions develop suddenly and clusters of outbreaks last from 2-4 weeks. The lesions are usually not pruritic
Describe the lesions in SJS? Pattern? Types? Signs?
o Lesions most commonly palms, soles, dorsum of hands and extensor surfaces
o Begin as macules develop into papules, vesicles, bullae, urticarial plaques, or confluent erythema
o Centre of lesions may be vesicular, purpuric, or necrotic
o Appearance of a target
o Nikolsky sign is positive (mechanical pressure to skin leading to blistering within minutes or hours)
Other symptoms in SJS?
- Oromucosal ulceration
- Dysuria or an inability to pass urine
- Painful red eye, purulent conjunctivitis, photophobia, blepharitis
Investigations in SJS?
- Serum electrolytes, glucose and bicarbonate essential to assess severity and dehydration
- Clinical diagnosis classification
- Skin biopsy
o Bullae are sub epidermal
o Epidermal cell necrolysis may be seen and perivascular areas are infiltrated with lymphocytes
Acute management of SJS?
o Identify and remove causative drug or underlying cause.
o Use of the ALDEN (Algorithm for assessment of Drug-induced Epidermal Necrolysis) may be useful
o A rapid assessment of prognosis should be made using the SCORTEN
Supportive therapy in SJS?
o Attention to airway and haemodynamic stability.
o Severe fluid loss
- IV fluid replacement and electrolyte correction.
o Analgesia
o Skin lesions are treated in the same way as for burns.
Mouth: mouthwashes; topical anaesthetics are useful in reducing pain and allowing the patient to take in fluids.
Eye care: frequent ophthalmology assessment and frequent eye drops, including antibiotic and steroid when required
What is thrush?
- Candida is a yeast-like fungus which is part of the normal commensal flora of the human gastrointestinal tract and the vagina
Risk factor for thrush?
- Complication of nappy rash
Symptoms of nappy rash/thrush??
- Bright red rash with clearly demarcated edge
- Satellite lesions beyond border
- Inguinal folds usually involved
- May have oral thrush too
Diagnosis of nappy rash?
Diagnosis is made clinically
Management of nappy rash?
- Frequent nappy changes
- Barrier ointment cream, expose to air
When would suspect thrush in nappy rash?
Worse in flexures or satellite lesions (a portion of the rash of cutaneous candidiasis in which a beefy red plaque may be found surrounded by numerous, smaller red macules located adjacent to the body of the main lesions)
Management of thrush in nappy rash?
- Topical antifungal e.g. nystatin ointment 6-hourly (if severe, may benefit from oral antifungal simultaneously)
What is thrush?
- Candida is a yeast-like fungus which is part of the normal commensal flora of the human gastrointestinal tract and the vagina
Risk factor for thrush?
- Complication of nappy rash
Symptoms of thrush??
- Bright red rash with clearly demarcated edge
- Satellite lesions beyond border
- Inguinal folds usually involved
- May have oral thrush too
Diagnosis of thrush?
Diagnosis is made clinically
Management of thrush?
- Frequent nappy changes
- Barrier ointment cream, expose to air
When would suspect thrush in nappy rash?
Worse in flexures or satellite lesions (a portion of the rash of cutaneous candidiasis in which a beefy red plaque may be found surrounded by numerous, smaller red macules located adjacent to the body of the main lesions)
Management of thrush?
- Topical antifungal e.g. nystatin ointment 6-hourly (if severe, may benefit from oral antifungal simultaneously)
What is nappy rash? Other names?
- Acute inflammatory reaction of the skin in the nappy area, which is most commonly caused by an irritant contact dermatitis. It is also known as ‘napkin dermatitis’ or ‘diaper dermatitis’
PAthology of nappy rash?
- Skin barrier function compromised by skin maceration (excessive hydration), friction between the skin and nappy, prolonged skin contact with urine and faeces, and resultant increased skin pH - Increase skin permeability and activate faecal enzymes which further act as skin irritants
What common secondary infections occur in nappy rash?
- Possible secondary infection with Candida albicans and bacteria (most commonly Staphylococcus aureus and streptococci)
Prognosis of nappy rash?
Uncomplicated nappy rash should settle with appropriate management in primary care, and typically lasts about three days. Can get secondary infections (thrush, viral).
Risk factors for nappy rash?
- Prolonged skin contact with urine and faeces
- Type of nappy used
- Soaps, detergents, or alcohol-based baby wipes.
- Mechanical friction from skin contact with nappies or over-vigorous cleaning.
- Pre-term infants
- Diarrhoea
Symptoms of nappy rash?
- Itchy and painful
- Well-defined areas of confluent erythema and scattered papules
- Over convex surfaces in contact with the nappy (the buttocks, genitalia, suprapubic area, and upper thighs)
- Sparing of the inguinal skin creases and gluteal cleft
- Glazed appearance if acute
DDx of nappy rash?
- Allergic contact dermatitis, perianal streptococcal dermatitis, infantile seborrheic dermatitis
- Atopic Eczema, eczema Herpeticum
- Psoriasis
Investigations in nappy rash?
- Clinical diagnosis and no investigations needed
- Skin swab for culture and sensitivity if secondary bacterial infection
Self-management of nappy rash?
- High absorbency nappy
- Ensure the nappy fits properly
- Leave nappies off for as long as possible
- Dry gently after cleaning — avoid vigorous rubbing.
- Do not use soap, bubble bath, lotions, talcum powder, or topical antibiotics which can have an irritant effect.
Drug therapy in nappy rash?
Emollients Topical hydrocortisone 1% cream
Prognosis of nappy rash?
Uncomplicated nappy rash should settle with appropriate management in primary care, and typically lasts about three days. Can get secondary infections (thrush, viral).
What is impetigo? When are lesions infectious?
- Highly-contagious Staph aureus or B-haemolytic Strep superficial skin infection.
- May be primary or complicate other skin disease (e.g. HSV infection, eczema, scabies).
- Nasal carriage is often source of infection
- Autoinoculation occurs and lesions are infectious until dry
Epidemiology of impetigo?
- Most common in infants and young children
Risk factors for impetigo?
- More common when pre-existing skin condition
- Overcrowding
- Poor hand hygiene
Symptoms of impetigo?
- Lesions well defined, usually start around nose & face
- Erythematous macules become vesicular/pustular and then rupture to give classical honey-coloured crusted lesions
- Superficial flaccid blisters can occur
Investigations in impetigo?
- Examination should confirm diagnosis
- If very severe, skin swabs could be done
Management of impetigo?
Consider hydrogen peroxide 1% cream (apply two or three times daily for 5 days) for people who are not systemically unwell or at a high risk of complications.
Otherwise:
- Topical fusidic acid for localised infections
- Oral flucloxacillin QDS for 7 days if severe
- Hygiene advice
- Avoid going to nursery or school until lesions are dry
