Milk-alkali syndrome

Milk-alkali syndrome is the triad of hypercalcaemia, renal failure and metabolic alkalosis secondary to ingestion of large amounts of calcium and absorbable alkali.

Historically it was due to milk and alkali being given for peptic ulcer disease.  It is now becoming more prevalent again due to widespread use of calcium carbonate in the prevention of osteoporosis.  Some estimate it to now be the third most common cause of in-hospital hypercalcaemia.

Treatment is to stop the causative agent and hydrate the patient.

    

                                                                                                                                                                         

Reference:

 Medalov, B. Milk-alkali syndrome. Mayo Clin Proc. 2009; 84(3): 261-267.

Dermatomyositis and polymyositis

Polymyositis is an idiopathic inflammatory disorder of skeletal muscle. When it is associated with cutaneous lesions it is dermatomyositis.

Features:

• Progressive proximal muscle weakness
• Dysphonia
• Dysphagia
• Fever
• Arthralgia/arthritis
• Muscle pain
• More rarely respiratory muscle weakness

Possible complications:

• Cardiomyopathy
• Intersitial lung disease
• Malignancy – commonest in dermatomyositis; most frequently lymphoma or ovarian or gastric cancer

Skin signs:

• Pathognomonic
• Gottron’s papules = erthematous papules over IP/MCP/elbow/knee joints
• Gottron’s sign = macules/plaques in same distribution as Gottron’s papules
• Non-pathognomic signs
• Heliotrope (liliac-purple) rash around eyelids/cheeks
• Shawl sign = macular rash over back and shoulders
• Periungal telangectasia

Investigations

• Raised CK/AST/ALT/LDH
• Raised ANA in 60-80%
• Anti-Jo antibodies in 20% of dermatomyositis
• Abnormal EMG

Treatment is:

• Prednisolone
• Methotrexate/cyclosporin
• Screen for malignancy

Reference:

Koler, R. and Montemarano, A. Dermatomyositis. Am Fam Physician. 2001; 64(9); 1565-1572.

Familial hypocalciuric hypercalcaemia

Familial hypocalciuric hypercalcaemia is an autosomal dominant condition which results in asymptomatic mild hypercalcaemia.

Bloods show mildly raised calcium and a normal or mildly raised PTH.

Familial hypocalciuric hypercalcaemia can be distinguished from primary hyperparathyroidism by fractional urinary calcium excreation:

• Patients with familial hypocalciuric hypercalcaemia: fractional urinary calcium excreation <0.01
• Patients with primary hyperparathyroidism: fractional urinary calcium excreation >0.02

It is important to distinguish the two as primary hyperparathyroidism requires treatment whilst familial hypocalciuric hypercalcaemia does not.

References:

Blackburn, M. and Diamond, T. Primary hyperparathyroidism and familial hyperparathyroid syndromes. Aust Fam Physician. 2007; 36(12): 1029-1033.

Taniegra, E. Hyperparathyroidism. Am Fam Physician. 2004; 69(2): 333-339.

Hyperparathyroidism

The parathyroid glands should release parathyroid hormone in response to low or falling calcium.  Parathyroid hormone (PTH) causes increased calcium and decreased phosphate.

Primary hyperparathyroidism

Primary hyperparathyroidism is the inappropriate secretion of PTH, resulting in hypercalcaemia.

Presentation was classically with the signs/symptoms of hypercalcaemia (‘bones, stones, abdominal groans and psychic moans’) but now 80% of cases are detected incidentally on bloods.

Biochemically there is a raised serum calcium, elevated or inappropriately normal PTH and often a low serum phosphate due to renal phosphate wasting.

85% of cases are caused by a single adenoma.

Parathyroid carcinoma is rare, affecting <0.5% of those with hyperparathyroidism.

Primary hyperparathyroidism may be hereditary – it is a feature of MEN I and MEN IIa.

Treatment

• Parathyroidectomy
• if calcium > 1.0mg/dl above upper limit of normal or creatinine clearance <60ml/min or osteoporosis or aged under 50
• 95% cure
• small risk of recurrent laryngeal nerve palsy
• risk of 'hungry bone syndrome' - associated with hypocalcemia, hypophosphatemia, and low urinary calcium excretion
• Medical management
• Adequate hydration
• Avoid immobility
• Alendronate to increase bone mineral density

NB it is important to differentiate primary hyperparathyroidism from familial hypocalciuric hypercalcaemia as the latter does not require any treatment.

Secondary hyperparathyroidism

Secondary hyperparathyroidism is characterised by raised PTH with low calcium - it is therefore an appropriate homeostatic response.

The commonest causes of secondary hyperparathyroidism are chronic renal failure and vitamin D deficiency.

Tertiary hyperparathyroidism

Tertiary hyperparathyroidism is seen after long-term secondary hyperparathyroidism due to hyperplasia of the parathyroid glands. It results in raised calcium and very raised PTH.  It generally occurs in end stage renal failure.

Summary

Small print gem: Hyperparathyroidism-jaw tumour syndrome is a rare condition in which there is a solitary parathyroid adenoma with associated bone lesion in the jaw and either Wilms’ tumour or renal cysts.

References

Bilezikian, J. et al. Guidelines for the management of asymptomatic primary hyperparathyroidism: Summary statement from the third international workshop. JCEM. 2009; 94(2): 335

Blackburn, M. and Diamond, T. Primary hyperparathyroidism and familial hyperparathyroid syndromes. Aust Fam Physician. 2007; 36(12): 1029-1033.

Taniegra, E. Hyperparathyroidism. Am Fam Physician. 2004; 69(2): 333-339.

Acromegaly

Acromegaly is a condition caused by excess growth hormone. Almost all cases are due to a pituitary tumour.

Classical features include:

• Soft tissue growth (large hands, coarsening of features etc)
• Hyperhydrosis
• Headaches
• Parasthesia
• Hypertension
• Impaired glucose tolerance/diabetes
• Hoarse voice

MRCP smaller-print features include:

• Colonic polyps
• Proximal myopathy
• Arthralgia
• Raised triglycerides
• Osteopenia
• Cardiomegaly – up to 90% in long-term patients
• OSA

Diagnosis is by the failure of GH to decrease to less than 1 microgram/l 2 hrs after an oral glucose challenge of 75g. False positives may occur in pregnancy, diabetics, renal/hepatic impairment, obesity or those on oestrogen therapy.

Serum IGF-1 is raised but this is only useful for screening.

Treatment:

• Transphenoidal surgery – 50-70% cure
• Octreotide = somatostatin analogue – 70% efficacy – causes gallstones in 30%...
• Pegvisomant = competitive GH receptor antagonist – 80% effective
• Radiotherapy – but takes up to 20 yrs(!) to work
• Dopamine agonists – bromocriptine not believed to be effective; cabergoline works in less than 10%

Small print gem: IGF1 is the target hormone for GH and mediates most of GH’s growth-promoting actions. 80% of IGF1 is made in the liver.

References:

Melmed, S. Acromegaly pathogenesis and treatment. J Clin Invest. 2009; 119(11): 3189-3202.

Melmed, S. et al. Guidelines for acromegaly management: an update. JCEM. 2009; 94(5): 1509.

Hypercalcaemia

Calcium homeostasis is primarily controlled by parathyroid hormone and hydroxylated vitamin D. Parathyroid hormone is produced by the parathyroid gland and vitamin D is either indigested in the diet or synthesized in the skin via exposure to sunlight. The mechanisms of action are outlined in the diagram below:

Hypercalcaemia can result in the following signs and symptoms (beyond the classical ‘stones, bones, abdominal groans and psychic moans…’)

• Polyuria
• Polydipsia
• Renal stones
• Nausea and vomiting
• Anorexia
• Constipation
• Confusion
• Psychotic behaviour
• Headache
• Bone pain
• Hypertension (rare)

Causes of hypercalaemia:

• Main causes (>90%)
• Primary hyperparathyroidism
• Malignant disease
• Other causes
• Sarcoidosis
• Immobilisation
• Vitamin A or D toxicity
• Drugs – thiazide, lithium
• Thyrotoxicosis
• Addisons
• Phaeochromocytoma
• Granulomatous disease –TB, Wegeners granulomatosis, histoplasmosis
• Milk-alkali syndrome 

Malignant disease can cause hypercalcaemia due to:

• Bone involvement – boney mets - ‘bronchus, breast, byroid, brostate and bidney’ (AKA bronchus, breast, thyroid, prostate and kidney) and myeloma
• Parathyroid Hormone related Peptide (PTHrP) produced by tumour, especially squamous cell tumours such as lung, oesophagus and breast, renal and bladder tumours.

ECG changes seen in hypercalcaemia can include: short QT, bradycardia, bundle branch block or AV block

Treatment is:

• Treat cause
• Normal saline
• Pamidronate

Small print gem: Hypercalcaemia increases sensitivity to digoxin

References:

Makras, P. and Papapoulos, S. Medical treatment of hypercalcaemia. Hormones (Athens). 2009; 8(2): 83-95.

Mundy, G. and Gulse, T. Hormonal control of calcium homeostasis. Clin Chem. 1999; 45(8 Pt2): 1347-1352.

Ralston, S. Medical management of hypercalcaemia. Br J Clin Pharmacol. 1992; 34(1):11-20.

Shaw, Q. On aphorisms. Br J Gen Pract. 2009; 59(569): 954-955.

Systemic sclerosis

Systemic sclerosis is a connective tissue disease characterised by fibrosis of the skin and visceral organs. It is relatively rare, affecting around 20 per 100.00. Females are more affected than males (6:1 in UK) and it is commonest in the 5th decade.

There are 2 main subdivision:

• Limited systemic sclerosis
• skin involvement is limited to face, hands and feet
• organs are involved later
• associated with anti-centromere antibodies in 50%
• CREST (calcinosis, Raynauds, oesophageal dysmotilty, sclerodatyl and telangectasia) is a subtype of limited systemic sclerosis

• Diffuse systemic sclerosis
• More skin involvement
• Earlier visceral involvement
• Anti Scl 70- found in 40%

Both types are associated with ANA in 85-98% of cases.

Anti-Ro is found in 9% of cases and is associated with a very severe and rapidly progressive disease.

Features of systemic sclerosis include:

• Raynauds – occurs in 98% of cases and is 1st symptom in 70% of cases
• GI tract involvement – strictures
• Skin involvement
• Telangiectasia
• Microstomia/peri-oral puckering
• Smooth shiny skin
• Renal failure
• Pulmonary hypertension/fibrosis
• Arthralgia

Treatment is

• Supportive
• Nifedipine/lorsartan for Raynaulds
• ACE I to protect kidneys
• d-penicillamine
• possibly steroids

Small print gem: side effects of penicillamine include proteinuria, leucopenia, thrombocytopenia, mucosal ulceration, cholestatis.

References:

Haustein, U. Systemic sclerosis-scleroderma. Dermatol Online J. 2002; 8(1):3.

Lim, I and Schrieber, L. Management of systemic sclerosis. Isr Med Assoc J. 2002; 4(11);953-957.

Arnold-Chiari Malformation

The Arnold-Chiari malformation is a malformation of the brain in which part of the brainstem and cerebellum are herniated into the cervical vertebral canal through the foramen magnum.

Arnold-Chiari malformations are classified anatomically:

• Type I
• downward displacement of cerebellar tonsils only
• associated with syringomyelia in up to 80% of cases
• many patients are asymptomatic
• mean age of onset 25
• Type II
• downward displacement of cerebellum, lower pons and medulla
• commonest form
• tends to present in childhood
• associated with spina bifida and hydrocephalus
• more severe form
• Type III
• cerebellar herniation into a high cervical meningocele
• Type IV
• Hypoplasia/aplasia of the cerebella hemispheres

Clinical manifestions of Arnold-Chiari include:

• Downbeat nystagmus
• Headaches – made worse by valsalva manoeuvres
• Vertigo
• Tinnitus
• Dysarthria
• Dysphagia
• Parasthesias
• Facial pain

References:

OMIM: Chiari malformation type I. Available at http://omim.org/entry/118420

OMIM: Chiari malformation type II. Available at http://omim.org/entry/207950

Pieh, C. and Gottlob, I. Arnold-Chiari malformation and nystagmus of skew. J Neurol Neurosurg Psychiatry. 2000; 69(1): 124-126.

Vitamin B12 deficiency

Vitamin B12 (cobalamin) is essential for DNA synthesis and neurological function.

It is found in meat and dairy products, so most people (except vegans) should have enough in their diet.

Absorption of B12 requires intrinsic factor (which is released from parietal cells in the stomach) to bind to it to facilitate its absorption as a complex uniquely in the terminal ileum.

Deficiency of B12 may result in:

• Megaloblastic anaemia
• Pancytopaenia
• Peripheral neuropathy
• Dementia/depression/psycohsis
• Subacute combined degeneration of the spinal cord

Causes of B12 deficiency can be split into:

• Insufficient intake – vegans, alcoholics, anorexics
• Lack of absorption
• Lack of intrinsic factor
• Pernicious anaemia - autoimmune condition in which autoantibodies to parietal cells cause B12 deficiency.  Female>males.
• Gastrectomy
• fish tapeworm causing disassociation of B12 from IF
• proton pump inhibitors – decreased acidity stops release of B12 from food
• Lack of terminal ileum
• Crohns disease
• Resection
• Whipples disease
• Imerslund-Grasbeck syndrome – rare autosomal recessive condition in which there is selective B12 malabsorption

Diagnosis is usually clinical combined with blood tests showing low B12. Folic acid must always be measured too and this should be replaced first if found to be low. If the result is inconclusive serum methylmalonic and homocysteine levels may be measured; if either are elevated this also suggests B12 deficiency (these are substrates for the two enzymatic reactions B12 usually catalyses)

If B12 deficiency is diagnosed the Schilling test may be performed to determine if the deficiency is due to lack of intrinsic factor. This involves giving radioactively labelled B12 orally and unlabelled B12 IM. The amount of labelled B12 in 24hrs of urine is then recorded. This procedure is then repeated with IF given at the same time – if the amount excreted increases, this suggests lack of IF is the cause of the B12 deficiency. The Schilling test has fallen from fashion, replaced by blood tests for IF antibodies (pathognomic for pernicious anaemia – specificity 100%, sensitivity 70%) or parietal cell antibodies (low specificity)

Treatment of B12 deficiency is to treat the cause/give B12.

Small print gem: The body has approximately 5 years worth of B12 stored, 'just in case.'

References:

Hvas, A. and Nexo, E. Diagnosis and treatment of vitamin B12 deficiency – an update. Haematologica. 2006; 91(11): 1506-1512.

Oh, R. and Brown, D. Vitamin B12 deficiency. Am Fam Physician. 2003; 67(5): 979-986.

Schjonsby, H. Vitamin B12 absoprtion and malsorption. Gut. 1989; 30(12): 1686-1691.

Paget disease of bone

Paget disease of bone is a condition characterised by focal regions of accelerated bone turnover due to increased number and size of osteoclasts resulting in disorganised bone structure. It affects mainly the axial skeleton.

Risk factors for Pagets:

• Increasing age - it is rare in under 40s
• Anglo-saxon origin
• Positive family history
• Males slightly more affected than females

Features of Paget disease of bone include:

• Bone pain
• Bone deformities – bowing of a limb, bossing of the skull
• Fractures
• Arthritis
• Hearing loss
• Tinnitus
• Headache
• Cardiac failure

However, it is often asymptomatic

Osteosarcoma develops in less than 1% of patients

Bloods show raised ALP and a normal calcium and phosphate
A bone scan should be performed.

Treatment

• No cure
• Bisphosphonates (which block osteoclast formation and induce osteoclast apoptosis) can induce remission
• Calcintonin (which blocks osteoclast formation and action) can also induce remission

References:

Kotowicz, M. Paget disease of bone – Diagnosis and indications for treatment. Australian Fam Phys. 2004; 33(3): 97-192.

OMIM: Paget disease of bone. Available at http://omim.org/entry/602080?search=paget&highlight=paget

Roodman, G. and Windle, J. Paget disease of bone. J Clin Invest. 2005; 11(2): 200-208. 

Peutz Jegher Syndrome

Peutz Jegher Syndrome is an autosomal dominant condition characterised by:

• hamartomatous polyps in gastrointestinal tract
• pigmented 'freckles' (macules) on lips, face, palms and soles

The only identified mutations causing PJS are of gene LKB1 (also known as STK11)

Complications of PJS include:

• Predisposition to malignancies – over 90% will get a cancer
• Obstruction/intususception
• GI bleeding
• Anaemia
• Abdominal pain

Reference

Kopacova, M., Tacheci, I., Rejchrt, S. and Bures, J. Peutz-Jeghers syndrome: diagnostic and therapeutic approach. World J Gastroenterol. 2009; 15(43):5397-5408.

Carcinoid tumours

Carcinoid tumours are neuroendocrine tumours. The majority (55%) are found in the GI tract with the commonest location being the small intestine, especially the ileum (note that previously the appendix was thought to be the commonest location). A further 30% of carcinoid tumours are found in the lungs.

They primarily secrete serotonin (5HT) but may also produce other substances.

They are classically associated with carcinoid syndrome, features of which include:

• Flushing – this may be provoked by foods such as bananas, tomatos, kiwi or cheese, or by alcohol or exercise
• Diarrhoea
• Bronchospasm
• Hypotension
• Pellagra – due to both serotonin and niacin needing tryptophan as a precursor
• Right-sided heart disease – especially fibrosis of the tricuspid valve.

However, note that to get carcinoid syndrome serotonin must reach the circulation. Since the liver metabolises serotonin, carcinoid syndrome will only occur if there is liver involvement or the tumour is in a location whereby the circulation can bypass the liver – for example the foregut.

Complications of carcinoid tumours include appendicitis, obstruction or intussception.

Diagnosis of carcinoid tumours is by:

1. 24hr urinary 5-HIAA (which is a metabolite of serotonin) – only positive if it is a secretory tumour
2. plasma chromograffin

Treatment of carcinoid tumours is:

• surgery
• ocreotide = somatostatin analogue

If these tumours are over-handled during surgery or out-grow their blood supply, a massive 'hormone hit' can be released in one go, causing a carcinoid crisis.

Features of a carcinoid crisis:

• vasodilation
• hypotension
• tachycardia
• bronchoconstriction
• hyperglycaemia

This must be treated with an infusion of ocreotide.

5 yr survival for patients with small bowel carcinoid is around 60%

Patients with carcinoid heart disease have a worse prognosis.

Small print gems: False elevation of urinary 5-HIAA can occur in coeliac sprue, Whipples disease SBO and if the patient eats avocados, bananas or walnuts. False elevation of plasma chromogranin can occur in liver/renal failure, IBD, multiple myeloma and chronic PPI use.

References

Aggarwal, G., Obideen, K. and Wehbi, M. Carcinoid tumors: what should increase our suspicion? Cleve Clin J Med. 2008; 75(12):849-855.

Pinchot, S., Holen, K., Sippel, R. and Chen, H. Carcinoid tumors. Oncologist. 2008; 13(12):1255-1269.

QT interval

The QT interval is that sneaky part of the ECG measured from the start of the QRS complex to the end of the T wave. I call it sneaky as as clinicians we rarely pay it much attention, then it just happens to get a bit on the long side and opppss… we have a ventricular arrhythmia on our hands. It represents the time taken for complete contraction and relaxation of the ventricles.

The first thing to learn about the QT interval is that it decreases as heart rate increases. It is therefore necessary to correct it, which is achieved by using either Bazetts or Fridericias formula.

Bazetts = corrected QT = QT/square root of RR interval

Fridericias = corrected QT = QT/cube root of RR interval

Upper limit of normal is generally taken to be 450ms in a man and 470ms in a woman (for some bizarre reason I remember 450 by singing the song 'brimful of asha on the 45' then just remember that females are 20 more)

Classical pattern of deterioration in long QT is long QT leading to torsade de pointes then either VT or VF.

There are multiple causes of long QT:

1. Familial

• Romano-Ward Syndrome
• Jervell-Lange-Nielson Syndrome

2. Metabolic

• low Mg/Ca/K
• low temperature
• low thyroid (also known as hypothyroidism…)

3. Drugs

• class I and III antiarrhythmics
• macrolides (erthyromycin, clarithromycin)
• quinolones (ciprofloxacin)
• TCA/haloperidol/risperidone/SSRIs
• antiemetics (ondansetron, prochlorperazine, domperidone)
• cocaine, methadone
• organophosphates
• antihistamines

4. Other

• MI
• myocarditis
• SAH

In terms of remembering the drugs which can cause long QT I think of it as lots of the ‘antis’ – antibiotics, antiarrhythmics, antiemetics, antihistamines, antidepressants and antipyscotics.

Treatment is by treating the underlying cause/stopping underlying medication or in familial cases with beta blockers and possibly an ICD.

Note that if VT occurs due to long QT amiodarone should not be given as a treatment.

Small print gem: The mechanism for most potential QT-prolonging medications is inhibition of the KCNH2-encoded HERG potassium channel. HERG stands for human ether-à-go-go related gene – and no, I didn’t make that name up.

References

Ayad, R. et al. Causes and management of drug-induced long QT syndrome. Proc (Bayl Univ Med Cent). 2010 July; 23(3): 250–255.

Delaney, J., Mittal, S., and Sherrid, M. Current perspectives on congenital long QT syndrome. Anadiky Kardiyol Derg 2009; 9:Suppl 2; 3-11.

Woosley RL. QT Drug Lists by Risk Groups Tucson, AZ: Arizona Center for Research and Education on Therapeutics, 2009. Available at http://www.azcert.org/medical-pros/drug-lists/drug-lists.cfm; accessed June 18th 2011.

Haemochromatosis

Primary haemochromatosis is an autosomal recessive disorder which results in increased intestinal absorption of iron leading to accumulation of iron and its deposition in multiple organs. 

The commonest mutation is of the HFA gene, specifically the mutation C282Y.

Patients are now most commonly diagnosed by an incidental finding/biochemically. The classical presentation however was lethargy, arthralgia and (in males) impotence. 

Diagnosis tends to be in the 4th decade. 

Clinical manifestations of haemochromatosis may be split into those which are reversible and those which are not: 

• Reversible manifestations 
• Bronzing of the skin (melanin deposition) 
• Grey pigmentation of the skin (iron deposition) 
• Cardiomyopathy 
• Hepatomegaly 
• Irreversible manifestations: 
• Cirrhosis 
• Hepatocellular carcinoma 
• Hypopituitism 
• Hypothyroidism 
• Diabetes mellitus 
• Athropathy 
• pseudogout 

Investigations 

• Serum transferrin saturation is best initial screening test - >45% suggests haemochromatosis
• Raised serum ferritin is a sensitive but not specific investigation (as an acute phase protein it will also be raised in infection/inflammation) 
• HFE mutation analysis (genetic testing) if transferrin saturation or serum ferritin is abnormal and haemochromatosis is suspected
• Liver biopsy is now only indicated if ferritin >1000 or LFTs abnormal.  The classic stain used is Perls stain (blue in colour)
• risks of liver biopsy: bleeding 1-6%; mortality 1 in 10,000.

Treatment 

• Regular venesection 
• Possibly chelation with deferoxamine or deferasirox 

Secondary haemochromatosis is almost always due to an hereditary or acquired disorder of erythropoiesis. 

Causes include: 

• Thalasseamia 
• Sickle cell anaemia 
• Hereditary spherocytosis 
• Myelofibrosis 

Treatment is with chelation. 

References:

Adams,P. and Barton, J. How I treat hemochromatosis. Blood. 2010; 116(3): 317-325. 
Bacon, B. et al. Diagnosis and management of hemochromatosis: 2011 Practice guidelines by the American Association for the Study of Liver Diseases. Hepatology. 2011; 54(1).

Brandhagen, D., Fairbanks, V. and Baldus, W. Recognition and management of hereditary hemochromatosis. Am Fam Physician. 2002; 65(5): 853-861. 

Cayley, W. Haemochromatosis. BMJ. 2008; 336(7642): 506. 

Gattermann, N. The treatment of secondary hemochromatosis. Dtsch Arztebl Int. 2009; 106(30): 499-504.

Gangrene, Gas gangrene and necrotizing fasciitis

Gangrene

Gangrene is the death of tissue due to ischaemia. It can be divided into:

• dry gangrene = ischaemia only
• wet gangrene = ischaemia plus infection.

Treatment is debridement and antibiotics.

Necrotizing fasciitis

Necrotizing fasciitis is severe infection of the deep soft tissue, including fascia. 50% of patients have a skin injury prior to developing necrotizing fasciitis. Early presentation is erythema, swelling, and pain out of proportion to the presentation.

2 types

• Type 1: polymicrobial
• Type 2: group A streptococcus (strep pyogenes) and staphylococcus aureus

Treatment is surgical debridement and antibiotics

Mortality is around 25%

Fournier’s gangrene = Form of infective necrotising fasciitis of the perineal, genital or perianal regions Increased risk in those with diabetes, alcoholism or other immunosupression

Meleney’s gangrene = Form of gangrene that occurs postoperatively

Gas Gangrene

Gas gangrene is a necrotizing infection characterised by muscle necrosis, gas production and often septic shock.  It is most commonly caused by clostridium perfringens, which is a gram negative rod.  Most cases follow a contaminated traumatic injury (e.g. a farmer on a pitchfork) but occasionally cases can be spontaneous.  Treatment is urgent surgical debridement and antibiotics.

Small print gem: Around 10% of patients with clostridial infections have an underlying malignancy.                 

References

Davies, D., Wallace, A. and Irving, M. Meleney’s synergistic gangrene following a caesarean section. Proc R Soc Med. 1975; 68(11): 746-747. 

Delbridge, M., Turton, E. and Kester, R. Spontaneous fulminant gas gangrene. Emerg Med J. 2005; 22(7): 520-521.

Shimizu, T. and Tokuda, Y. Necrotizing fasciitis. Intern Med. 2010; 49(12): 1051-1057. 

Stevens, D. and Byrant, A. The role of clostridial toxins in the pathogenesis of gas gangrene. Clin Infect Dis. 2002; 35(Suppl 1): S93-S100.

Thwaini, A. et al. Fournier’s gangrene and it emergency management. Postgrad Med J. 2006; 82(970): 516-519.

Sarcoidosis

Sarcoidosis is a multi-system granulomatous disorder of unknown cause.

It is asymptomatic in up to 40% of cases, being discovered incidentally on a routine CXR.

Features of sarcoidosis may be divided into pulmonary and non-pulmonary:

Pulmonary features of sarcoidosis:

• dry cough
• progressive dyspnoea
• chest pain
• wheeze

Non-pulmonary features of sarcoidosis include:

• Lymphadenoapthy
• Skin involvement (25%). Includes erythema nodosum (affects 1 in 10) and lupus pernio (which affects more females)
• Polyarthralgia
• Occular involvement – anterior uveitis, glaucoma, cataract
• Neurosarcoid – including Bells palsy
• Hypercalcaemia (10%). Due to dysregulated production of calcitriol by activated macrophages and granuloma
• Cardiac involvement
• Renal stones

90% of patients with sarcoid will have an abnormal CXR.

Staging of CXR in sarcoid is:

• 0 = clear CXR
• 1 = bilateral hilar lymphadenopathy
• 2 = bilateral hilar lymphadenopathy plus pulmonary infiltration
• 3 = pulmonary infiltration only
• 4 = fibrosis, honeycombing, pleural involvement

Note staging is purely radiological and does not correlate with pulmonary function

Investigations:

• CXR
• Bloods
• Raised serum ACE (50%)
• Raised calcium (10%)
• Deranged LFTs
• Possibly lymphoenia
• Biopsy
• Lung function tests

Management:

• BHL alone doesn't need treatment
• acute sarcoidosis : NSAIDs and bed rest
• prednisolone ( 40mg OD for 4-6 weeks then reducing dose over one year) is indicated if:
• symptomatic pulmonary disease or progressive loss of lung function
• cardiac disease
• neurological disease
• eye disease
• symptomatic hypercalcaemia

Methotrexate decreases requirement for steroid

Prognosis: 2/3 remit within a decade, 1/3 progressive

Small print gem: Löfgren's syndrome is a form of sarcoidosis consisting of arthritis, erythema nodosum, and bilateral hilar adenopathy. Females more affected than males. Good prognosis – most cases resolve.

References

Grutters, J. and van der Bosch, J. Corticosteroid treatment in sarcoidosis. Eur Respir J. 2006; 28(3):627-636.

Iannuzzi, M., Rybicki, B. and Teristein, A. Sarcoidosis. N Engl J Med 2007; 357(21):2153-2165.

Wu, J. and Schiff, K. Sarcoidosis. Am Fam Physician. 2004; 70(2):312-322.