Rheumatoid factor is an IgM antibody that targets the Fc portion of IgG.

The clinical picture of an itchy, scaly annular rash after a walk in the park suggests erythema migrans. The pathogen responsible is a spirochete, Borrelia Burgdorferi transmitted by ticks leading to Lyme disease. Doxycycline is the antibiotic of choice if no contraindications.

Melanocytic nevi are benign neoplasms or hamartomas composed of melanocytes. Melanocytes are derived from the neural crest and migrate during embryogenesis to selected ectodermal sites (primarily the skin and the CNS), but also to the eyes and the ears.
They tend to appear during early childhood and during the first 30 years of life. They may change slowly, becoming raised, changing color or gradually fading.. Pregnancy can increase the number of naevi as well as the degree of hyperpigmentation.
They may become malignant and this should be suspected if the naevus increases in size, develops an irregular surface or becomes darker, itches or bleeds.

According to the updated GMC guidelines, patient safety is more important than anything else, thus the correct thing to do is inform your colleague’s employing body.

The differential diagnosis of bilateral exercise-induced pain would include metabolic muscle disease, lumbar canal stenosis and intermittent claudication. The patient’s age, history and lack of other risk factors make the latter two options unlikely.

The syndrome described is in fact McArdle’s disease (myophosphorylase deficiency). This is a disorder of carbohydrate metabolism. Clinical features of pain and fatigue are precipitated in early exercise, as carbohydrates cannot be mobilized to provide an energy substrate to the muscle. With prolonged exercise, fatty acid metabolism provides energy, and symptoms lessen. The dark urine described is likely to represent myoglobinuria following rhabdomyolysis. Definitive diagnosis of most metabolic muscle diseases relies on muscle biopsy and enzyme analysis.

Lidocaine is an example of class IB antiarrhythmics.

The Vaughan-Williams classification of antiarrhythmics
I: Membrane stabilizing agents
IA: Quinidine, Procainamide, Disopyramide
IB: Lidocaine, Mexiletine
IC: Propafenone, Flecainide
II: β blockers – Propranolol, Esmolol
III: Agents widening AP – Amiodarone, Dronedarone, Dofetilide, Ibutilide, Sotalol
IV: Calcium channel blockers – Verapamil, Diltiazem
V: Miscellaneous – Digoxin, adenosine, magnesium

The patient has paroxysmal nocturnal haemoglobinuria (PNH) complicated by acute hepatic vein thrombosis (Budd–Chiari syndrome).

PNH is an acquired clonal disorder of haematopoietic stem cells, characterised by variable combination of intravascular haemolysis, thrombosis, and bone marrow failure. Diagnosis is made by flow cytometric evaluation of blood, which confirms the CD55 and CD59 deficiencies and deficiency of expression of other GPI-linked proteins. This test is replacing older complement-based assays such as the Ham test and sucrose lysis test.

The rash is a characteristic sign of meningitis. Added to photophobia, headache and neck rigidity, meningitis is highly suggested diagnosis. IV antibiotics should be started immediately.

Osteopenia is an early sign of bone weakening that is less severe than osteoporosis.
The numerical result of the bone density test is quantified as a T score. The lower the T score, the lower the bone density. T scores greater than -1.0 are considered normal and indicate healthy bone. T scores between -1.0 and -2.5 indicate osteopenia. T scores lower than -2.5 indicate osteoporosis.
DEXA also provides the patient’s Z-score, which reflects a value compared with that of person matched for age and sex.
Z-score values of –2.0 SD or lower are defined as below the expected range for age and those above –2.0 SD as within the expected range for age.

Lateral epicondylitis (tennis elbow) is an overuse injury of the hand and finger extensor tendons that originate in the lateral humeral epicondyle that occurs following repeated or excessive pronation/supination and extension of the wrist (e.g., in racquet sports). Clinical features include pain and tenderness over the lateral epicondyle and along extensor muscles and thickening of the tendons. The examiner holds the patient’s hand with the thumb placed over the lateral epicondyle – The patient makes a fist, supinates the forearm, deviates radially, and extends the fist against the examiner’s resistance which will result in pain over the lateral epicondyle. Conservative treatment includes rest, physiotherapy and orthotic braces. If this fails corticosteroids and lidocaine injections are employed. Surgery is indicated in patients with persistent symptoms despite 6 months of conservative treatment. Excision of abnormal tendon tissue; longitudinal incisions (tenotomies) in scarred and fibrotic areas to promote healing.