In patients with acute renal tubular necrosis, infection in the form of gram-negative septicaemia is the most common cause of death, especially while the patient is awaiting spontaneous recovery of their renal function.

Hypogammaglobulinemia occurs due to a variety of underlying primary or secondary immunodeficient states, including HIV which is suspected in this case. The most commonly recognised clinical feature is recurrent infection.

Exposure to excessive androgens is usually accompanied by premature epiphyseal maturation and closure, resulting in a final adult height that is typically significantly below that expected from parental heights.

congenital adrenal hyperplasia (CAH) is associated with precocious puberty caused by long term exposure to androgens, which activate the hypothalamic-pituitary-gonadal axis. Similarly, CAH is associated with hyperpigmentation and hyperreninemia due to sodium loss and hypovolaemia.

Positive predictive value = TP (true positives) / [TP + FP (false positives)] = 40 / (40 + 20) = 0.66

Prolactinomas, benign lesions that produce the hormone prolactin, are the most common hormone-secreting pituitary tumours.
Based on its size, a prolactinoma can be classified as a microprolactinoma (< 10 mm diameter) or a macroprolactinoma (>10 mm diameter). If the prolactinoma is large enough to compress the surrounding normal hormone-secreting pituitary cells, it may result in deficiencies of one or more hormones (e.g., thyroid-stimulating hormone [TSH], growth hormone [GH], adrenocorticotropic hormone). However, the patient has microadenoma so it is unlikely to cause compression manifestations.
Hyperprolactinemia inhibits GnRH secretion from the medial basal hypothalamus and LH release from the pituitary.

People aged 16 or over are entitled to consent to their own treatment. This can only be overruled in exceptional circumstances. Children under the age of 16 can consent to their own treatment if they’re believed to have enough intelligence, competence and understanding to fully appreciate what’s involved in their treatment. This is known as being Gillick competent.

Otherwise, someone with parental responsibility can consent for them.
This could be:
the child’s mother or father
the child’s legally appointed guardian
a person with a residence order concerning the child
a local authority designated to care for the child
a local authority or person with an emergency protection order for the child.
Giving the blood transfusion is therefore both clinically and ethically the right course of action.
Jehovah’s Witnesses frequently carry a signed and witnessed Advance Decision Document listing the blood products and autologous procedures that are, or are not, acceptable to them It is appropriate to have a frank, confidential discussion with the patient about the potential risks of their decision and the possible alternatives to transfusion, but the freely expressed wish of a competent adult must always be respected.

Here, the patient seems to be intolerant to standard metformin. In such cases, modified-release preparations is considered as the most appropriate next step.
There is some evidence that these produce fewer gastrointestinal side-effects in patients intolerant of standard-release metformin.

Metformin is a biguanide and reduces blood glucose levels by decreasing the production of glucose in the liver, decreasing intestinal absorption and increasing insulin sensitivity.
Metformin decreases both the basal and postprandial blood glucose.
Other uses: In Polycystic Ovarian Syndrome (PCOS), Metformin decreases insulin levels, which then decreases luteinizing hormone and androgen levels. Thus acting to normalize the menstruation cycle.

Note:
Metformin is contraindicated in patients with severe renal dysfunction, which is defined as a glomerular filtration rate (GFR) less than 30 ml/min/1.732m2.
Metformin overdose has been associated with hypoglycaemia and lactic acidosis, for this reason, it has a black box warning for lactic acidosis.

There is a strong suspicion of Thrombotic Thrombocytopenic Purpura (TTP) in this patient as he presents with neurological changes (from confusion to convulsions and coma), fever, haemolysis, thrombocytopenia, and renal failure. Additionally, TTP cases may present with jaundice, splenomegaly, and hypertension as seen in this patient. With a diagnosis of TTP, recent studies have shown that platelet transfusion is not recommended in this case because it has been shown to increase the risk for arterial thrombosis and mortality possibly due to increased aggregations.

Urea breath test is the most sensitive test to determine if there has been RESOLUTION/ERADICATION of the infection with H. pylori. The best test for initial diagnosis would be EGD with biopsy.

The history gives you a woman who is on inhaled steroid therapy. It is always a good idea for patients to rinse their mouths well after using inhaled steroids. Odynophagia (pain on swallowing) is a symptom of oesophageal candidiasis, which is the most likely answer given the steroids. Typically, you might see this in someone who is immunocompromised (classically, in HIV+ patients).

Myc is a family of regulator genes and proto-oncogenes that code for transcription factors.

A tumor suppressor gene, or antioncogene, is a gene that protects a cell from one step on the path to cancer. When this gene mutates to cause a loss or reduction in its function, the cell can progress to cancer, usually in combination with other genetic changes. Tumor suppressor genes can be grouped into categories including caretaker genes, gatekeeper genes, and landscaper genes; the classification schemes are continually evolving.
Examples include:
Gene Associated cancers
p53 Common to many cancers, Li-Fraumeni syndrome
APC Colorectal cancer
BRCA1 Breast and ovarian cancer
BRCA2 Breast and ovarian cancer
NF1 Neurofibromatosis
Rb Retinoblastoma
WT1 Wilm’s tumour

One of the most important complications in patients with PKD is being affected by berry aneurysms that may burst, causing a subarachnoid haemorrhage, which seems to be the case in this patient.

The patient (known case of acromegaly) seems to have developed cholelithiasis (presenting with right upper quadrant pain) probably due to octreotide.

It is a long-acting analogue of somatostatin which is released from D cells of the pancreas and inhibits the release of growth hormone, glucagon, and insulin.

Uses
– Acute treatment of variceal haemorrhage
– Acromegaly
– Carcinoid syndrome
– Prevent complications following pancreatic surgery
– VIPomas
– Refractory diarrhoea

Adverse effects
Gallstones (secondary to biliary stasis)

Other options:
– Bromocriptine – a dopamine agonist with side effects arising from its stimulation of the brain vomiting centre.
– Desmopressin – predominantly used in patients with diabetes insipidus by increasing the presence of aquaporin channels in the distal collecting duct to increase water reabsorption from the kidneys. The main side effects include headache and facial flushing due to hypertension.
– Metformin – mainly reduces hepatic gluconeogenesis in patients with type 2 diabetes, common side effects include diarrhoea, vomiting, and lactic acidosis
– Levothyroxine – synthetic thyroxine used in patients with hypothyroidism, common side effects result from incorrect dosing and mimic the symptoms of hyperthyroidism.

Guillain-Barre syndrome is an immune mediated demyelination of the peripheral nervous system often triggered by an infection (classically Campylobacter jejuni). Characteristic features include progressive weakness of all four limbs, and it is classically ascending, affecting the lower extremities first. Sensory symptoms tend to be mild.

Functional neurological syndrome can be discounted due to presence of hard neurological signs. Multiple sclerosis can be excluded because of the presence of lower motor neuron signs and absence of upper motor neuron signs. Chronic inflammatory demyelinating polyneuropathy is the chronic form of Guillain-Barre syndrome.

To confirm the diagnosis, especially in patients with negative anti-Ro or anti-La antibodies, labial gland biopsy is done. In performing a labial biopsy, the surgeon typically makes a shallow 1/2 inch wide incision on either side of the inner lip after numbing the area with a local anaesthetic. Schirmer’s test determines whether the eye produces enough tears to keep it moist. This test can be done for ocular symptoms of Sjogren syndrome but is of no diagnostic importance as it can be positive with many other diseases.

Bulimia nervosa is a serious, potentially life-threatening eating disorder characterized by a cycle of bingeing and compensatory behaviours such as self-induced vomiting designed to undo or compensate for the effects of binge eating.

According to the DSM-5, the official diagnostic criteria for bulimia nervosa are:
Recurrent episodes of binge eating. An episode of binge eating is characterized by both of the following:
Eating, in a discrete period of time (e.g. within any 2-hour period), an amount of food that is definitely larger than most people would eat during a similar period of time and under similar circumstances.
A sense of lack of control over eating during the episode (e.g. a feeling that one cannot stop eating or control what or how much one is eating).
Recurrent inappropriate compensatory behaviour in order to prevent weight gain, such as self-induced vomiting, misuse of laxatives, diuretics, or other medications, fasting, or excessive exercise.
The binge eating and inappropriate compensatory behaviours both occur, on average, at least once a week for three months.
Self-evaluation is unduly influenced by body shape and weight.
The disturbance does not occur exclusively during episodes of anorexia nervosa.

Antidepressants as a group – particularly selective serotonin reuptake inhibitors (SSRIs) – are the mainstay of pharmacotherapy for bulimia nervosa. These may be helpful for patients with substantial concurrent symptoms of depression, anxiety, obsessions, or certain impulse disorder symptoms. They may be particularly good for patients who have not benefited from or had suboptimal response to suitable psychosocial therapy or who have a chronic, difficult course in combination with other treatments.

Food and Drug Administration (FDA) approved treatments
Fluoxetine (Prozac): Initial dose 20 mg/d with advance over 1–2 weeks to 60 mg/d in the morning as tolerated. Some patients may need to begin at a lower dose if side effects are intolerable. A maximum dose of 80 mg/d may be used in some cases.

Scabies is due to an infestation of Sarcoptes scabiei and most commonly presents with these symptoms. The organism resides in burrows in a pattern specifically affecting the interdigital spaces and the skin folds of the arms and legs. The infection spreads from one person to another, especially in populated communities, through close contact.
Henoch-Schönlein purpura is a type of vascular inflammation.
Psoriasis rash is characterised by scaly plaques affecting the extensor surfaces of the body. Pemphigus vulgaris and bullous pemphigoid both are bullous disorders of the skin. They may present as crusted, weeping, diffuse lesions and there may be involvement in other sites; erosions in the mouth are typically involved in pemphigus vulgaris. Bullous pemphigoid involves the flexural areas and may be associated with a new medication.

This patient is a case of chronic myeloid leukaemia (CML) and should be started on imatinib as the first-line drug of choice.

The given history is more compatible with spontaneous pneumothorax. Left-sided pneumothoraxes may be associated with a clicking noise, which is heard with each heart-beat and can sometimes be heard by the patient.

The development of hepatic fibrosis reflects an alteration in the normally balanced processes of extracellular matrix production and degradation. [6] The extracellular matrix, the normal scaffolding for hepatocytes, is composed of collagens (especially types I, III, and V), glycoproteins, and proteoglycans. Increased collagen in the space of Disse (space b/w sinusoids and hepatocytes) leads to capillarization of sinusoids, and stellate cells also have contractile properties when activated. This is fibrosis processes. This can lead to the development of portal hypertension.