There are many causes of hypomagnesaemia. Heavy binge alcohol intake can lead to a loss of magnesium from tissues and increased urinary loss. Chronic alcohol abuse has been reported to deplete the total body supply of magnesium. This is the most likely cause in this case.
Schwartz PJ. Predicting the Unpredictable Drug‐Induced QT Prolongation and Torsades de Pointes. J Am Coll Cardiol 2016; 67:1639–50.
https://www.sciencedirect.com/science/article/pii/S0735109716003387
35. Answer: K
This case is a very typical occurrence in hospital. The patient is in pain after the fracture and is waiting for surgery. He receives opioid analgesia regularly. Opiate toxicity should be suspected when the clinical triad of depressed level of consciousness (reduced GCS), respiratory depression, and pupillary miosis are present. It is important to remember opioid exposure/toxicity does not always result in miosis and that respiratory depression is the most specific sign. Respiratory failure and respiratory acidosis is due to hypoventilation.
Airway control and adequate oxygenation is the primary supportive treatment. Intravenous naloxone should be given in patient with reduced level of consciousness and/or respiratory depression. The usual dose is between 0.4 and 2 mg. The onset of effect following intravenous naloxone is 1–2 min; maximal effect is observed within 5–10 min. A repeat dose is indicated for partial response and can be repeated as often as needed. To avoid precipitous withdrawal (nausea, vomiting, agitation) and consequent aspiration, naloxone may be started with low doses such as 0.1 mg and titrated up gradually until reversal of respiratory depression is achieved.
Boyer E. Management of Opioid Analgesic Overdose. New England Journal of Medicine. 2012;367(2):146–155.
https://pubmed.ncbi.nlm.nih.gov/22784117/
3 Dermatology
Questions
Answers can be found in the Dermatology Answers section at the end of this chapter.
1 1. A 65‐year‐old man with a history of type 2 diabetes presents with blistering skin lesions affecting the trunk and upper and lower extremities. Histopathology of a punch biopsy and an excision biopsy of the affected skin and blister confirms a diagnosis of bullous pemphigoid.Which one of the following medications may have contributed to the development of bullous pemphigoid?Gliclazide.Insulin.Linagliptin.Metformin.
2 2. A 27‐year‐old woman with an 18‐year history of type 1 diabetes and a 5‐year history of hypothyroidism now presents with fatigue, bloating, abdominal pain, diarrhoea, and a 4 kg weight loss over the past 6 months. On examination, she has symmetric papulovesicles over the external surface of the extremities and on the trunk.What other classic characteristic of her skin lesion would you expect to find?Absence of any pain.Firm nodules on the scalp.Intense pruritus.Target lesions on the palms.
3 3. A 34‐year‐old woman has developed several tender red swellings on her shins and right ankle (picture shown below) over the past 3 weeks. She has been feeling generally unwell and has a low‐grade fever. She has not had a recent sore throat, cough, or sputum. Over the past 12 months she has had recurrent aphthous ulcers in her mouth but no genital ulceration. She has also experienced intermittent abdominal pain, diarrhoea, and lost 7 kg of body weight. She is a current heavy smoker and drinks alcohol only occasionally. On examination, she is afebrile, there are no aphthous ulcers, active arthritis, lymphadenopathy, or organomegaly. The initial investigation results and CXR are displayed below.TestsResultsNormal valuesSodium136 mmol/L135–145Potassium3.5 mmol/L3.5–5.2Urea5.9 mmol/L2.7–8.0Creatinine96 μmol/L60–100Calcium2.01 mmol/L2.10–2.60Albumin28 g/L38–48Bilirubin16 mmol/L2–24ALP63 U/L30–110GGT46 U/L0–60ALT52 U/L0–55AST45 U/L0–45Hb92 g/L135–175WBC16.5 x 109/L4.0–11.0Platelet259 x 109/L150–450MCV72 fL80–98ESR82 mm/h<20What is your most likely diagnosis?Crohn’s disease.Glandular fever.Lymphoma.Sarcoidosis.
4 4. An 18‐year‐old man presents to the emergency department with central colicky abdominal pain and arthralgia. He has become unwell with coryzal symptoms since yesterday. He reports smoky coloured urine and reduced oral intake due to sore throat. He does not have a significant past medical history and no history of intravenous drug use. On examination, a palpable rash is present on both legs (see below). He is hypertensive. Which of the following statement regarding this condition is correct?80% of patients will have a negative FOBT.90% of patients will have high level of serum IgA.90% of patients will have thrombocytopenia.90% of patients will have a positive ANCA and MPO.
5 5. Which of the following gene mutations are frequently detected in melanoma?BRAF and CDKN2A.Epidermal growth factor receptor (EGFR).K‐ras and p53.Vascular endothelial growth factor (VEGF).
6 6. A 58‐year‐old woman presents to the clinic following an excisional biopsy of an asymmetrical pigmented lesion on her right lower leg with widest diameter measuring 9 mm. The Breslow thickness has been reported at 4 mm. She is known to have poorly controlled type 2 diabetes, which is complicated by nephropathy, retinopathy, and neuropathy. She had several small foot and leg ulcers before which took a long time to heal. There is no documented macrovascular complication so far.The best management plan is:Require no wider local excision; however require a sentinel node biopsy.Require a wider local excision with a surgical margin of 2 cm and a sentinel node biopsy.Require a wider local excision with a surgical margin of 1 cm and a sentinel node biopsy.Require a wider local excision with a surgical margin of 4 cm without a sentinel node biopsy.
7 7. A 58‐year‐old butcher presents with a 4‐month history of fatigue. He has noticed a few small blisters developing initially on both hands and since then the rash is getting worse especially when exposed to sun. He is concerned about the scarring marks left on his hands. He drinks two to three standard drinks of alcohol per day. He has no history of previous skin disease or other medical problems. He does not take any medication. His hands are shown below. The full skin examination reveals similar small lesions and scars on his face. The biochemistry results are shown below:TestsResultsNormal valuesHb170 g/L135–175Creatinine139 μmol/L80–120ALT98 U/L0–55AST155 U/L0–45GGT89 U/L0–60ALP169 U/L30–110LDH213 U/L120–250Ferritin547 μg/L30–300Transferrin saturation26 %10–55What is the most likely diagnosis?Bullous pemphigoid.Cutaneous lichen planus.Dermatitis herpetiforms.Porphyria cutanea tarda.
8 8. A 42‐year‐old woman presents with a 9‐month history of repeated facial flushing, often precipitated by sun exposure. She reports that the flushing occurs on the nose, both cheeks, and the central forehead. On examination, she has multiple telangiectasia on both malar surfaces, but no evidence of inflamed papules or pustules. There are no features suggestive of systemic lupus erythematosus.Which of the following treatments is most likely to be helpful in reducing her symptoms?Oral doxycycline.Oral isotretinoin.Topical brimonidine.Topical metronidazole.
9 9. An 82‐year‐old man with vascular dementia is constantly scratching his hands and elbows. There are diffuse scaly rashes on hands, elbows, and scrotum with several vesicles and scratch marks. A clinical diagnosis of scabies is made.Which of the following statements is true in regard to this patient?A skin biopsy should be performed prior to the treatment.He is at risk of having highly contagious crusted scabies.His pruritus is caused by direct irritation from mites and eggs.The mite can survive on bedding, clothes for more than one week.
10 10. A 40‐year‐old woman who