Diabetes insipidus (DI) is defined as the passage of large volumes (>3 L/24 hr) of dilute urine (< 300 mOsm/kg). It has the following 2 major forms:Central (neurogenic, pituitary, or neurohypophyseal) DI, characterized by decreased secretion of antidiuretic hormone (ADH; also referred to as arginine vasopressin [AVP])Nephrogenic DI, characterized by decreased ability to concentrate urine because of resistance to ADH action in the kidney.The boy most probably has nephrogenic diabetes insidious (DI) not central DI so he is not responding to the ADH treatment.

A micturating cystourethrogram (MCUG) is one type of imaging test also called a voiding cystourethrogram (VCUG). The MCUG can check whether the flow of urine from the child’s bladder is being blocked, or whether it goes up the wrong way. It can help diagnose certain conditions, including vesicoureteral reflux and posterior urethral valves.

Neonatal hypoglycaemia is a common yet serious condition characterized by blood sugar levels less than 2.2mmol/L during the first 3 days of life and less than 2.5mmol/L later on. There are multiple aetiologies and various risk factors that lead to hypoglycaemia in new-borns like prematurity, sepsis, inborn errors of metabolism, and maternal diabetes- induced hyperinsulinism in the new-born. Among the inborn errors of metabolism, fatty acid oxidation defects can lead to persistent hypoglycaemia in new-borns. One such defect is the medium- chain acyl CoA dehydrogenase deficiency, which is the enzyme needed for the breakdown of medium- chain fatty acids.

Osteochondromas, or osteocartilaginous exostoses, are the most common benign bone tumours, and tend to appear near the ends of long bones. The overgrowth can occur in any bone where cartilage forms bone, and they are capped by cartilage. They are most common in people between the ages of 10-20 years old.

The patient’s sugar levels typically show the Dawn phenomenon.Dawn phenomenon:This is an early morning rise in blood glucose levels secondary to a rise in hormones that increase blood glucose levels. The question suggests that he is undergoing a pubertal growth spurt, suggesting that an increase in these hormones is what has led to the higher morning glucose levels.Other options:- Inactivity at night-time: It is expected, and insulin dose should be adequate despite inactivity during the night.- Inadequate bedtime insulin: It is possible that this is a contributing factor. However, inadequate background insulin is also likely to result in high blood glucose in the day, which the question does not suggest.- Somogyi effect: There are no features suggestive of nocturnal hypoglycaemia that can cause the Somogyi effect.- Nocturnal glycogenesis: Glycogenesis would result in hypoglycaemia, not hyperglycaemia.

History of recurrent infections and failure to thrive (probably due to pancreatic enzyme insufficiency) is highly suggestive of cystic fibrosis. Pseudomonas has been identified as an important respiratory pathogen in patients with cystic fibrosis.

Correlation is a bivariate analysis that measures the strength of association between two variables and the direction of the relationship.Pearson r correlation: Pearson r correlation is the most widely used correlation statistic to measure the degree of the relationship between linearly related variables. Pearson’s correlation coefficient is the test that measures the statistical relationship, or association, between two continuous variables. It is known as the best method of measuring the association between variables of interest because it is based on the method of covariance. It gives information about the magnitude of the association, or correlation, as well as the direction of the relationship.The non-parametric Spearman or Kendall rank correlation coefficient is used if neither variable has a normal distribution or the sample size is small (i.e. <20).

Tension headache presents with pain that is pressing or tightening in quality, mild or moderate, and located bilaterally. It usually does not get worse with activities and may last from minutes to weeks.

Arnold-Chiari malformation type II is one of the congenital hindbrain abnormalities that leads to a disruption of the relationship between different hindbrain structures. It is characterized by congenital hydrocephalus, herniation of cerebellar tonsils into the pinal canal with an enlarged 4th ventricle, spina bifida associated with myelomeningocele, and various levels of denervation atrophy of the muscles of the lower limb. The association of type II Arnold-Chiari with myelomeningocele carries importance from an etiological perspective, forming the basis of CSF escape theory.

Lesions caused by herpes simplex virus may appear in various clinical stages. They are usually the result of an HSV-1 infection and they may appear on the face and neck. They start as fluid-filled blisters which eventually erupt into small painful ulcers.

Infants may require tracheal intubation if:- direct tracheal suctioning is required- effective bag-mask ventilation cannot be provided- chest compressions are performed- endotracheal (ET) administration of medications is desired- congenital diaphragmatic hernia is suspected, or – a prolonged need for assisted ventilation exists.

Breast milk jaundice is a type of jaundice associated with breast-feeding. It typically occurs one week after birth. The condition can sometimes last up to 12 weeks, but it rarely causes complications in healthy, breast-fed infants. The exact cause of breast milk jaundice isn’t known. However, it may be linked to a substance in the breast milk that prevents certain proteins in the infant’s liver from breaking down bilirubin. The condition may also run in families. Breast milk jaundice is rare, affecting less than 3 percent of infants. When it does occur, it usually doesn’t cause any problems and eventually goes away on its own. It’s safe to continue breast-feeding.

Food poisoning is defined as an illness caused by the consumption of food or water contaminated with bacteria and/or their toxins, or with parasites, viruses, or chemicals. The most common pathogens are Norovirus, Escherichia coli, Salmonella, Clostridium perfringens, Campylobacter, and Staphylococcus aureus.The following are some of the salient features of food poisoning:Acute diarrhoea in food poisoning usually lasts less than 2 weeks. Diarrhoea lasting 2-4 weeks is classified as persistent. Chronic diarrhoea is defined by duration of more than 4 weeks.The presence of fever suggests an invasive disease. However, sometimes fever and diarrhoea may result from infection outside the GI tract, as in malaria.A stool with blood or mucus indicates invasion of the intestinal or colonic mucosa.Reactive arthritis can be seen with Salmonella, Shigella, Campylobacter, and Yersinia infections.A profuse rice-water stool suggests cholera or a similar process.Abdominal pain is most severe in inflammatory processes. Painful abdominal cramps suggest underlying electrolyte loss, as in severe cholera.A history of bloating should raise the suspicion of giardiasis.Yersinia enterocolitis may mimic the symptoms of appendicitis.Proctitis syndrome, seen with shigellosis, is characterized by frequent painful bowel movements containing blood, pus, and mucus. Tenesmus and rectal discomfort are prominent features.Consumption of undercooked meat/poultry is suspicious for Salmonella, Campylobacter, Shiga toxin E coli, and C perfringens.Consumption of raw seafood is suspicious for Norwalk-like virus, Vibrioorganism, or hepatitis A.Consumption of homemade canned foods is associated with C botulinum.Consumption of unpasteurized soft cheeses is associated with Listeria, Salmonella, Campylobacter, Shiga toxin E coli, and Yersinia.Consumption of deli meats notoriously is responsible for listeriosis.Consumption of unpasteurized milk or juice is suspicious for Campylobacter, Salmonella, Shiga toxin E coli, and Yersinia.Salmonella has been associated with consumption of raw eggs.

Recommended regimens3 NRTI (e.g., zidovudine, lamivudine, abacavir) OR2 NRTI (e.g., lamivudine + abacavir) AND1 NNRTI (e.g., efavirenz) OR1 PI (e.g., lopinavir) OR1 INI (e.g., raltegravir)

Treating persons infected with C. trachomatis prevents adverse reproductive health complications and continued sexual transmission, and treating their sex partners can prevent reinfection and infection of other partners. Treating pregnant women usually prevents transmission of C. trachomatis to neonates during birth. Chlamydia treatment should be provided promptly for all persons testing positive for infection; treatment delays have been associated with complications (e.g., PID) in a limited proportion of women. To minimize disease transmission to sex partners, persons treated for chlamydia should be instructed to abstain from sexual intercourse for 7 days after single-dose therapy or until completion of a 7-day regimen and resolution of symptoms if present. To minimize risk for reinfection, patients also should be instructed to abstain from sexual intercourse until all of their sex partners are treated. Persons who receive a diagnosis of chlamydia should be tested for HIV, GC, and syphilis.

Language/Communication milestones of 2 years old:Points to things or pictures when they are named Knows names of familiar people and body parts Says sentences with 2 to 4 words Follows simple instructions Repeats words overheard in conversation Points to things in a book

Croup is the most common aetiology for hoarseness, cough, and onset of acute stridor in febrile children. Symptoms of coryza may be absent, mild, or marked. The vast majority of children with croup recover without consequences or sequelae.

The adult height potential may be calculated for a male child by (father’s height in cm + mother’s height in cm) / 2 then add 7 cm.In the scenario provided: (170 + 150)/2 + 7 = 167 cm = 1.67 m.For a female child by (father’s height in cm + mother’s height in cm) / 2 then minus 7 cm.This can then be plotted on a height centile chart to find the mid-parental centile.Causes of short stature include:- Normal variant (often familial)- Constitutional delay of growth and puberty- Chronic illness, e.g. cystic fibrosis, inflammatory bowel disease- Endocrine: growth hormone deficiency, hypothyroidism, steroid excess syndromes: Turner’s, Down’s, Prader-Willi- Skeletal dysplasias, e.g. achondroplasia

When a child with joint problems presents with red-eye, the likelihood of anterior uveitis must be excluded by involving an ophthalmologist in the assessment. This is because uveitis is the most common extra-articular manifestation of juvenile idiopathic arthritis.Other options:- Cataract: It does not give rise to a red-eye, but leukocoria. Often this would have been picked up at an earlier age. – A patient with a corneal foreign body almost would almost invariably give a suspicious history (onset while playing outdoors etc.), as well as have marked symptoms of ocular discomfort (red, watery and painful eyes). – A child with periorbital cellulitis often presents acutely unwell and distressed. – A child with an uncorrected refractive error often complains of being unable to see in class and does not normally present with ocular redness.

The thyroglossal duct cyst is the most common congenital anomaly of the central portion of the neck. The thyroglossal duct cyst is intimately related to the central portion of the hyoid bone and usually elevates along with the larynx during swallowing. Thyroglossal cysts can be defined as an irregular neck mass or a lump which develops from cells and tissues left over after the formation of the thyroid gland during the developmental stages.

Usage of inhaled corticosteroids are less associated with systemic adverse effects. However they are associated with local complications including dental caries and most commonly dysphonia.

Before the test, the patient was likely to have the disease being tested for. Their pre test odds were 2, making them twice as likely to have the disease. After testing positive, their pretest odds of 2 and the likelihood ratio of 3 are multiplied to produce 6 as the post test odds. The patient is now 6 times as likely to have the disease after the test. Likelihood ratios above 10 or below 0.1 are strong evidence to rule in and rule out a diagnosis. The negative likelihood ratio is not known here, but does not subtract from the interpretation of the outcomes in this patient.

Possible Zika virus infections have been identified in breastfeeding babies, but Zika virus transmission through breast milk has not been confirmed. Additionally, we do not yet know the long-term effects of Zika virus on young infants infected after birth. Because current evidence suggests that the benefits of breastfeeding outweigh the risk of Zika virus spreading through breast milk, CDC continues to encourage mothers to breastfeed, even if they were infected or lived in or travelled to an area with risk of Zika.

Lesch-Nyhan syndrome is a condition that occurs almost exclusively in males. This condition is inherited in an X-linked recessive pattern It is characterized by neurological and behavioural abnormalities and the overproduction of uric acid. Uric acid is a waste product of normal chemical processes and is found in blood and urine. Excess uric acid can be released from the blood and build up under the skin and cause gouty arthritis (arthritis caused by an accumulation of uric acid in the joints). Uric acid accumulation can also cause kidney and bladder stones.The nervous system and behavioural disturbances experienced by people with Lesch-Nyhan syndrome include abnormal involuntary muscle movements, such as tensing of various muscles (dystonia), jerking movements (chorea), and flailing of the limbs (ballismus). People with Lesch-Nyhan syndrome usually cannot walk, require assistance sitting, and generally use a wheelchair. Self-injury (including biting and head banging) is the most common and distinctive behavioural problem in individuals with Lesch-Nyhan syndrome.

Allergy: A history of a prior allergic-like reaction to contrast media is associated with an up to a 5-fold increase in the likelihood of experiencing a subsequent reaction. Also, any patient with a predilection to allergic reactions may predispose them to a reaction after the administration of contrast media. Given the increased risk of severe life-threatening anaphylaxis related to the administration of contrast media in the setting of the history of atopy, the risk versus benefits should be discussed before following through with the procedure. A premedication regimen may be used to reduce the risk of anaphylaxis.Asthma: A history of asthma may be indicative of a higher likelihood of developing a contrast reaction. Cardiac status: Attention must be turned to patients with significant cardiac disease (congestive heart failure, aortic stenosis, severe cardiomyopathy, and/or pulmonary hypertension), as higher volumes and osmolality of contrast material may result in an increased risk for a contrast reaction.Renal insufficiency: Contrast nephrotoxicity is defined as the rapid deterioration of renal function after the administration of contrast media when no other aetiology can be determined from the clinical records. The major predisposing risk factors include pre-existing renal insufficiency (defined as serum creatinine level >1.5 mg/dL) and diabetes. Other risk factors include dehydration, cardiovascular disease, the use of diuretics, advanced age (>70 years old), hypertension, and hyperuricemia. Obtaining multiple contrast-enhanced studies within 24 hours is also thought to increase the risk for contrast-induced nephrotoxicity. Miscellaneous: Relative contraindications to the use of high osmolality iodinated contrast media (HOCM) in patients with pheochromocytoma, sickle cell disease, and multiple myeloma have been reported. Although the administration of low osmolality or iso-osmotic contrast media may be beneficial in patients with pheochromocytoma and sickle cell disease, little evidence suggests that these agents mitigate the risks associated with multiple myeloma.

Haemophilia A has an X-linked recessive pattern of inheritance, meaning that is a 50% chance of having a son with haemophilia and 50% chance of the daughters being carriers of the haemophilia gene.

Diarrhoea is defined as having three or more loose or liquid stools per day, or as having more stools than is normal for that person. Severe diarrhoea, causing fluid loss and loss of bicarbonate, will result in marked dehydration and metabolic acidosis.

The drainage of cerebral spinal fluid from the third ventricle to the fourth ventricle is carried out by the cerebral aqueduct. The cerebral aqueduct is the narrowest passageway in the entire ventricular system and thus forms the most common site of blockage of flow of cerebrospinal fluid. The interventricular foramen allows passage of CSF to the third ventricle. The foramen of Luschka and Magendie are located on the fourth ventricle and allow passage of CSF to the subarachnoid space from the ventricular system. The pontine cistern is a space located on the ventral aspect of the pons. The cisterna magna is an opening on the subarachnoid space between the pia matter and the arachnoid.

Benign neonatal sleep myoclonus is a condition characterised by neonatal onset myoclonic jerks during NREM. Characteristic for this disorder is the absence of electroencephalographic findings.

Among the options provided, the most characteristic finding that can be expected in his patient’s urine microscopy is RBC casts. Red cell casts are a characteristic feature of acute nephrotic syndrome. Other options:- Hyaline casts may be seen in normal urine, particularly after exercise. – Coarse granular casts occur in glomerular and tubular disease. – Tubular cell casts may be seen in patients with acute tubular necrosis. – The presence of 10 or more white blood cells/mm3 is abnormal and indicates an inflammatory reaction, most commonly due to infection.