Hereditary C1 inhibitor deficiency leads to recurrent angioedema without urticaria or pruritus. Physical triggers include dental work, surgery or intubation. Medical triggers include angiotensin-converting enzyme (ACE) inhibitor, tamoxifen, oestrogen-containing medications (e.g., hormone replacement therapy and oral contraceptives). It is diagnosed on the basis of low levels of C1 esterase inhibitor or elevated levels of dysfunctional C1 esterase inhibitor. C4 levels are low between attacks. IgE levels, eosinophils, skin prick tests and RASTs are helpful in other allergic conditions and asthma but not of use in this case.

In statistical hypothesis testing there are 2 types of errors:
– type I: the null hypothesis is rejected when it is true – i.e. Showing a difference between two groups when it doesn’t exist, a false positive.
– type II: the null hypothesis is accepted when it is false – i.e. Failing to spot a difference when one really exists, a false negative.

Patients with disseminated gonococcal arthritis may present with dermatitis-arthritis syndrome (60%) of with localized septic arthritis. (40%). Arthritis-dermatitis syndrome includes the classic triad of dermatitis, tenosynovitis, and migratory polyarthritis. Gout usually involves a singe joint and does not cause vesicopustular skin rash. Reactive arthritis has ocular symptoms (conjunctivitis), urethritis, and arthritis. Fungal arthritis occurs rarely and it may occur after a surgical infection or fungal spread hematogenously. it presents with tender, red, hot and swollen joint with loss of range of motion.

An odds ratio (OR) is a measure of the association between an exposure and an outcome. The OR represents the odds that an outcome will occur given a particular exposure, compared to the odds of the outcome occurring in the absence of that exposure. Odds ratios are most commonly used in case-control studies, however they can also be used in cross-sectional and cohort study designs as well (with some modifications and/or assumptions). Where

a = Number of exposed cases

b = Number of exposed non-cases

c = Number of unexposed cases

d = Number of unexposed non-cases

OR=(a/c) / (b/d) = ad/bc

Scleritis, or inflammation of the sclera, is usually painful whereas episcleritis is not painful.

Keratoconjunctivitis sicca is usually bilateral and associated more with dryness, burning and itching.

Attacks or exacerbations of multiple sclerosis (MS) are characterized by symptoms that reflect central nervous system (CNS) involvement, hence upper motor neuron symptoms are seen.

The most likely diagnosis is hypertrophic obstructive cardiomyopathy which is suggestive by the history, positive family history and ECG findings. Two-dimensional echocardiography is diagnostic for hypertrophic cardiomyopathy. In general, a summary of echocardiography findings includes abnormal systolic anterior leaflet motion of the mitral valve, LV hypertrophy, left atrial enlargement, small ventricular chamber size, septal hypertrophy with septal-to-free wall ratio greater than 1.4:1, mitral valve prolapse and mitral regurgitation, decreased midaortic flow, and partial systolic closure of the aortic valve in midsystole.

The patient has spinal cord compression until proven otherwise. Urgent assessment is required.

Spinal cord compression is an oncological emergency and affects up to 5% of cancer patients. Extradural compression accounts for the majority of cases, usually due to vertebral body metastases. One of the most common causes of spinal cord compression is osteoarthritis. It is also more commonly seen in patients with lung, breast, or prostate cancer.

Clinical features include:
1. Back pain: the earliest and most common symptom, may worsen on lying down or coughing
2. Lower limb weakness
3. Sensory changes: sensory loss and numbness
4. Neurological signs: depending on the level of the lesion.
Lesions above L1 usually result in upper motor neurone signs in the legs. Lesions below L1 usually cause lower motor neurone signs in the legs and perianal numbness. Tendon reflexes are increased below the level of the lesion and absent at the level of the lesion.

Management options are:
1. High-dose oral dexamethasone
2. Urgent MRI for consideration of radiotherapy or surgery

Corticosteroids are well known for their ocular complications such as glaucoma and cataracts.

Causes for ST segment elevation other than myocardial infarction
Natural variants
-Early repolarization
-Left ventricular hypertrophy and hypertrophic cardiomyopathy
-Left bundle branch block
Artefacts
-Leads mispositioning
-Electrical cardioversion
Cardiovascular diseases
-Pericarditis/ Myocarditis
-Aortic dissection
-Prinzmetal’s angina
-Takotsubo Cardiomyopathy
-Brugada Syndrome and arrhythmogenic right ventricular cardiomyopathy/dysplasia
Pulmonary diseases
-Pulmonary thromboembolism
-Pneumothorax
-Atelectasis and pulmonary metastases
Gastrointestinal diseases
-Acute pancreatitis
-Acute cholecystitis
Other conditions
-Hyperkalaemia
-Drug induced ST segment elevation (e.g. – clozapine)
-Haemorrhagic cerebrovascular disease

Coronary artery disease and myocardial infarction can be excluded with a negative angiogram and a slightly elevated troponin. Hypertrophic cardiomyopathy can be excluded with cardiovascular MR findings. Left ventricular aneurysm usually occurs following a myocardial infarction, but there is no positive history for that. The characteristic findings on cardiovascular MR confirms the diagnosis of Takotsubo cardiomyopathy.