Because Charcot-Marie-Tooth disease (type 1) is an autosomal dominant condition; therefore, there is a 50% chance that the children of this patient will be affected.

Superior vena cava (SVC) obstruction is an oncological emergency caused by compression of the SVC and is most commonly associated with lung cancer.

Some causes of the condition include:
1. Common malignancies: non small cell lung cancer, lymphoma
2. Other malignancies: metastatic seminoma, Kaposi’s sarcoma, breast cancer
3. Aortic aneurysm
4. Mediastinal fibrosis

Clinical features of SVC obstruction include:
1. Dyspnoea: most common
2. Swelling of the face, neck, and arms: conjunctival and periorbital oedema may be seen
3. Headache: often worse in the morning
4. Visual disturbances
5. Pulseless jugular venous distension

Management options are:
1. General: dexamethasone, balloon venoplasty, stenting
2. Small cell lung cancer: chemotherapy and radiotherapy
3. Non small cell lung cancer: radiotherapy

Friedreich’s ataxia is an autosomal recessive disorder that usually begins before the end of the teens. It has an estimated prevalence in Europe of 1 in 50,000 and life expectancy is around 40–50 years. Neurological features include a progressive ataxia, cerebellar dysarthria, lower limb areflexia, decreased vibratory sensation and proprioception, and pyramidal weakness. Pes cavus and scoliosis are also both seen. Cardiomyopathy occurs in over 70% of cases. Less common features include optic atrophic, diabetes mellitus, and deafness.

A formula for estimating glomerular filtration rate (eGFR) is the Modification Diet of Renal Disease (MDRD) equation which takes into account the following variables: serum creatinine, age, gender, and ethnicity. Thus, serum urea is not required in this formula.

Caplan’s syndrome is defined as the association between silicosis and rheumatoid arthritis (RA). It is rare and usually diagnosed in an advanced stage of RA. It generally affects patients with a prolonged exposure to silica.

Caplan’s syndrome presents with rheumatoid lung nodules and pneumoconiosis. Originally described in coal miners with progressive massive fibrosis, it may also occur in asbestosis, silicosis and other pneumoconiosis. Chest radiology shows multiple, round, well defined nodules, usually 0.5 – 2.0 cm in diameter, which may cavitate and resemble tuberculosis.

Cefalexin should be avoided in this patient.
This patient is known to have a severe penicillin allergy. None of the above antibiotics are penicillin based. However, 0.5 – 6.5% of patients who are proven to have an IgE mediated penicillin allergy will also be allergic to cephalosporins, including cefalexin.

Penicillin, cephalosporins, and carbapenems are all members of the beta-lactam group of antibiotics and share a common beta-lactam ring. There is, therefore, a small risk of allergy cross-over between all these antibiotics. The rates of allergy cross-over are lower with second and third-generation cephalosporins than first-generation cephalosporins such as cefalexin.

It is important to question the patient carefully to ascertain what symptoms they had on exposure to penicillin. Symptoms such as an urticarial rash or itching make it more likely that they have an IgE mediated allergy.

Proton pump inhibitors can reduce gastric acid secretion by up to 99%. Acid production resumes following the normal renewal of gastric parietal cells.

Difficulty in initiating movement (bradykinesia), postural instability and unilateral symptoms (initially) are typical of Parkinson’s. Essential tremor symptoms are usually worse if arms are outstretched and eased by rest and alcohol.

Arterial ischemia ulcers present with many of the symptoms observed in this patient: ulcer on the lower extremities, pain, swelling, yellow sores, a punched-out appearance, the foot turning red when dangling from a bed. Smoking a lot is also known to be a causative factor here. This type of ulcer develops due to damage to the arteries caused by a lack of blood flow to the tissue – they are also deep wounds. Venous ischemic ulcers usually form in the knee or inner ankle area as opposed to the foot.

Churg-Strauss disease (CSD) is one of three important fibrinoid, necrotizing, inflammatory leukocytoclastic systemic small-vessel vasculitides that are associated with antineutrophil cytoplasm antibodies (ANCAs).
The first (prodromal) phase of Churg-Strauss disease (CSD) consists of asthma usually in association with other typical allergic features, which may include eosinophilia. During the second phase, the eosinophilia is characteristic (see below) and ANCAs with perinuclear staining pattern (pANCAs) are detected. The treatment would therefore be different from asthma. For most patients, especially those patients with evidence of active vasculitis, treatment with corticosteroids and immunosuppressive agents (cyclophosphamide) is considered first-line therapy