Deck 10 Flashcards
(20 cards)
How is chronic granulomatous disease diagnosed?
Negative nitroblue-tetrazolium test
Abnormal dihydrorhodamine flow cytometry
What is Chediak-Higashi syndrome and how does it present?
Neutrophil disorder resulting from a defect in microtubule polymerisation leading to reduced phagocytosis
Affected children have partial albinism and peripheral neuropathy, recurrent bacterial infections
What is leucocyte adhesion deficiency and how does it present?
Neutrophil disorder caused by defect in LFA-1 integrin on neutrophils
Leads to recurrent bacterial infections, delay in umbilical cord sloughing and absence of neutrophils at site of infection
How does common variable immunodeficiency present?
It is a B cell disorder that results in hypogammaglobulinaemia
It may predispose to lymphoma and autoimmune disorders
What is Bruton’s X-linked agammaglobulinaemia?
B cell disorder characterised by a defect in Bruton’s tyrosine kinase resulting in a severe block in B cell development
Patients develop recurrent bacterial infections, there is an absence of B cells and reduced immunoglobulins of all classes
How might selective IgA deficiency manifest?
Recurrent sinus and respiratory tract infections
Associated with coeliac disease
May develop severe reactions to blood transfusions (due to anti-IgA antibodies)
What is DiGeorge syndrome and how does it manifest?
T cell disorder caused by 22q11.2 deletion resulting in failure to develop the 3rd and 4th pharyngeal pouches
Manifestations include congenital heart disease (e.g. tetralogy of Fallot), learning difficulties, hypocalcaemia, recurrent viral/fungal diseases, cleft palate
List some combined B and T cell disorders.
SCID (multiple causes)
Ataxia Telangiectasia (defect in DNA repair, leads to cerebellar ataxia, telangiectasia, recurrent chest infections and increased risk of malignancy)
Wiskott Aldrich Syndrome (defect in WASP gene, recurrent bacterial infection, eczema, thrombocytopaenia, autoimmune diseases)
Hyper IgM Syndrome (mutation in CD40 gene, hepatitis, diarrhoea, PCP infection)
What are the recommendations for secondary prevention of osteoporotic fractures in postmenopausal women?
1st line: alendronate
2nd line: risedronate or etidronate
3rd line: strontium ranelate or raloxifene
What is myotonic dystrophy and what are its main features?
Inherited myopathy that presents at around 20-30 years
Autosomal dominant trinucleotide repeat disorder (DM1 caused by CTG repeat, DM2 is caused by repeat expansion of ZNF9 gene)
Main features are myotonic facies, frontal balding, bilateral ptosis, cataract and dysarthria
Also associated with dysphagia, diabetes mellitus, mild mental impairment, testicular atrophy, heart block and cardiomyopathy
How should giant cell arteritis be managed?
Uncomplicated (no visual involvement or tongue/jaw claudication) –> PO prednisolone 40-60 mg OD
Complicated (visual involvement and/or tongue/jaw claudication) –> IV methylprednisolone 500-1000 mg for 3 days before starting oral prednisolone
List some features of severe malaria.
Schizonts on a blood film Parasitaemia > 2% Hypoglycaemia Acidosis Temperature > 39 °C Severe anaemia Cerebral malaria (seizures, coma) Acute renal failure ARDS DIC
What is an important contraindication of anticholinergic treatment for urge incontinence?
Previous history of urinary retention
NOTE: it should also be avoided in the elderly as it can worsen confusion
What is the main test used to screen for latent TB?
Mantoux
IGRA is used if Mantoux is positive
What can precipitate pompholyx eczema?
High humidity and heat
What are the main translocations associated with the various types of lymphoma/leukaemia?
Follicular Lymphoma - t(14,18) Burkitt Lymphoma - t(8,14) CML - t(9,22) Mantle Cell Lymphoma - t(11, 14) Ewing Sarcoma - t(11, 22) APML - t(15, 17)
How should wounds at risk of tetanus infection be managed?
Full course of tetanus vaccines (5) with last dose < 10 years –> no vaccine or immunoglobulin
Full course of tetanus vaccines with last dose > 10 years –> if tetanus prone then reinforcing dose of vaccine, if very high-risk give reinforcing dose and tetanus immunoglobulin
If vaccination history unclear –> give reinforcing dose, give tetanus immunoglobulin if tetanus-prone or high-risk wound
What are the main features of acute intermittent porphyria?
autosomal dominant
defect in porphobilinogen deaminase
female and 20-40 year olds more likely to be affected
typically present with abdominal symptoms, neuropsychiatric symptoms
hypertension and tachycardia common
urine turns deep red on standing
What are the main features of porphyria cutanea tarda?
most common hepatic porphyria
defect in uroporphyrinogen decarboxylase
may be caused by hepatocyte damage e.g. alcohol, oestrogens
classically photosensitive rash with bullae, skin fragility on face and dorsal aspect of hands
urine: elevated uroporphyrinogen and pink fluorescence of urine under Wood’s lamp
manage with chloroquine
What are the main features of variegate porphyria?
autosomal dominant defect in protoporphyrinogen oxidase photosensitive blistering rash abdominal and neurological symptoms more common in South Africans
