Epistaxis is common in younger children usually due to nose picking. After the episode is over no active management is required and reassurance should be given to the patient and his attendants.

Immunoglobulin G (IgG) glomerular immune deposits are seen more commonly in HSP compared to IgA nephropathy.The presentation of the child is highly suggestive of Henoch-Schönlein purpura (HSP). It is an IgA-mediated, autoimmune hypersensitivity vasculitis that targets the small vessels of the skin, GI tract, kidneys, and joints.It is most commonly seen in children aged 3 – 6years and is twice as common in boys than girls. Preceding viral URTI with low-grade pyrexia is common. The most common organism associated with HSP is, however, Group A streptococcal infection A.A purpuric rash is seen on the back of the legs and buttocks and can less frequently, affect the arms. Arthralgia is common (usually knees/ankles) in these patients. Abdominal pain and bloody diarrhoea may occur. And half of the children with HSP have renal involvement. Rarely, it can lead to end-stage renal failure.Treatment includes adequate hydration, occasionally steroids, and other immunosuppressants. The disease can recur in 1 in 3 children.

Angio-oedema, is the rapid swelling of the skin, mucosa and submucosal tissues. The underlying mechanism typically involves histamine or bradykinin. The version related to histamine is to due an allergic reaction to agents such as insect bites, food, or medications. The version related to bradykinin may occur due to an inherited C1 esterase inhibitor deficiency, medications e.g. angiotensin converting enzyme inhibitors, or a lymphoproliferative disorder.

The P value is defined as the probability under the assumption of no effect or no difference (null hypothesis), of obtaining a result equal to or more extreme than what was actually observed. The P stands for probability and measures how likely it is that any observed difference between groups is due to chance. Being a probability, P can take any value between 0 and 1. Values close to 0 indicate that the observed difference is unlikely to be due to chance, whereas a P value close to 1 suggests no difference between the groups other than due to chance. Thus, it is common in medical journals to see adjectives such as “highly significant” or “very significant” after quoting the P value depending on how close to zero the value is.A lower p-value is sometimes interpreted as meaning there is a stronger relationship between two variables. However, statistical significance means that it is unlikely that the null hypothesis is true (less than 5%).To understand the strength of the difference between two groups (control vs. experimental) a researcher needs to calculate the effect size.

The equation, lung function = 3.2 + (1.7 x height) is linear, but this does not necessarily mean that the relationship itself is linear. The equation is able to predict that taller individuals are more likely to have greater lung functions. No information is given on whether the coefficients and the R value are statistically significant.

Septic (infectious) arthritis is a bacterial infection of the joint space. Contamination occurs either via the bloodstream, iatrogenically, or by local extension (e.g., penetrating trauma). Patients with damaged (e.g., patients with rheumatoid arthritis) or prosthetic joints have an increased risk. Patients usually present with an acutely swollen, painful joint, limited range of motion, and a fever. Suspected infectious arthritis requires prompt arthrocentesis for diagnosis. In addition to the immediate broad-spectrum antibiotic therapy, surgical drainage and debridement may be necessary to prevent cartilage destruction and sepsis.

Congenital heart diseases such as complete atrioventricular septal defects are most likely to cause large left to right shunts leading to faltering growth due to chronic severe hypoxia, pulmonary oedema, and feeding problems. Isolated atrial septal defects or ventricular septal defects result in relatively smaller shunts. Pulmonary stenosis and bicuspid aortic valve do not cause chronic systemic hypoxia. People with these conditions are often asymptomatic and only show some symptoms with intense physical activity.

Developmental milestones at 4 months of age:Social and Emotional:Smiles spontaneously, especially at people Likes to play with people and might cry when playing stops Copies some movements and facial expressions, like smiling or frowningLanguage/CommunicationBegins to babble Babbles with expression and copies sounds he hears Cries in different ways to show hunger, pain, or being tiredCognitive (learning, thinking, problem-solving)Lets you know if he is happy or sad Responds to affectionReaches for a toy with one hand Uses hands and eyes together, such as seeing a toy and reaching for it Follows moving things with eyes from side to side Watches faces closely Recognizes familiar people and things at a distance Movement/Physical DevelopmentHolds head steady, unsupported Pushes down on legs when feet are on a hard surface May be able to roll over from tummy to back Can hold a toy and shake it and swing at dangling toys Brings hands to mouth When lying on stomach, pushes up to elbows

Intussusception is the most suggested case here based on the child’s symptoms. The urgent course of treatment is to bring the child to a paediatric surgical unit. If air reduction attempts fail, surgery will have to be done. Risk factors for intussusception include viral infection and intestinal lymphadenopathy.

Vaccines should not be given to a feverish child.

Erythema infectiosum is an acute viral illness caused by Parvovirus B19. It is usually a mild flu-like illness and produces a maculopapular rash, appearing initially on the cheeks and then spreading towards extremities. The rash usually spares the palms and soles and gives a slapped appearance to the cheeks. It can be described as having a fishnet appearance on the body.

The combination of frequent infections, eczema, and thrombocytopaenia are characteristic of Wiskott-Aldrich syndrome, which is due to an abnormality in the WASP gene. It is an X-linked recessive disorder that causes primary immunodeficiency owing to a combined B- and T-cell dysfunction.The other listed options are:1. PKD1: polycystic kidney disease2. CFTR: cystic fibrosis3. HFE1: haemochromatosis4. RET: multiple endocrine neoplasia, Hirschsprung’s disease

The following methods are adopted for the treatment of DKA:

– Fluids: Bolus of 10 ml/kg of normal saline. Stop at three boluses to avoid precipitating cerebral oedema. The remaining deficit has to be corrected over 48 hours. Strict input/output, U&E, and pH monitoring is necessary in such patients.

– Insulin: Insulin infusion can be initiated at 0.05-0.1 unit/kg/hour. It is essential to monitor blood glucose closely, and the aim is to decrease by 2 mmol/hour.

– Potassium: Initially, it will be high, but following insulin administration, the levels drop quickly as K+ enters cells with glucose, and thus, replacement is almost always necessary.

– Acidosis: Bicarbonate is avoided unless pH is less than 7. Acidosis will get corrected with the correction of fluid and insulin deficits. The definitive treatment is directed towards correcting the underlying precipitants of DKA, e.g. sepsis, infections.

Torsade de pointes is an uncommon and distinctive form of polymorphic ventricular tachycardia (VT) characterized by a gradual change in the amplitude and twisting of the QRS complexes around the isoelectric line.Conditions associated with torsade include the following:Electrolyte abnormalities – Hypokalaemia, hypomagnesemia, hypocalcaemiaEndocrine disorders – Hypothyroidism, hyperparathyroidism, pheochromocytoma, hyperaldosteronism, hypoglycaemiaCardiac conditions – Myocardial ischemia, myocardial infarction, myocarditis, bradyarrhythmia, complete atrioventricular (AV) block, takotsubo cardiomyopathyIntracranial disorders – Subarachnoid haemorrhage, thalamic hematoma, cerebrovascular accident, encephalitis, head injuryNutritional disorders – Anorexia nervosa, starvation, liquid protein diets, gastroplasty and ileojejunal bypass, celiac diseaseRisk factors for torsade include the following:Congenital long QT syndromeFemale genderAcquired long QT syndrome (causes of which include medications and electrolyte disorders such as hypokalaemia and hypomagnesemia)BradycardiaBaseline electrocardiographic abnormalitiesRenal or liver failure

Transposition of the great arteries (TGA) is a common congenital heart lesion that presents with severe cyanosis that is likely to appear in the first day of life.

The child has experienced the Somogyi phenomenon. It is a phenomenon where there’s a morning rise in blood sugar. Often it occurs as posthypoglycemic hyperglycaemia and follows nocturnal hypoglycaemia. The mechanism is the production of counter-regulatory hormones like glucagon, cortisol and adrenaline, which increase glucose. She can be managed by reducing her evening insulin dosage and increasing complex carbohydrates for supper (evening meal).Type I diabetes mellitus:It is a chronic illness that is characterised by the inability to produce insulin. It is caused by autoimmune destruction of the beta cells in the pancreas and often presents with ketoacidosis.The patient can present with symptoms suggestive of polyuria, polydipsia, and weight loss. There can be periods of islet cell regeneration in these patients, which leads to a ‘honeymoon period’ of remission.Symptoms occur when there is < 20% of islet cell activity left.Insulin therapy is required in almost all children with type 1 diabetes.Most children require multiple insulin injections throughout the day via subcutaneous insulin pumps.Target HbA1c in these patients is 48 mmol/mol according to the updated NICE guidelines.

Because the medical history included tonsillitis followed by haematuria and hypertension, there is a strong suspicion of a case of post-streptococcal glomerulonephritis (PSGN). Patients with PSGN usually have serological findings showing depressed serum haemolytic component CH50 and serum concentrations of C3. Sometimes depressed C4 levels are also apparent, but not always, therefore, the answer to this question is: depressed CH50 level.

Insertion sites and sensor sites should be rotated each time the infusion set or glucose sensor is changed. This keeps the tissue healthy and allows previous sites to completely heal before reusing them. Change infusion set every 2 to 3 days to help prevent infection.

Bone age is a valuable tool for determining the skeletal maturation in children. An X-ray of the left hand and wrist or knee is used to calculate bone age, which is then compared with the chronological age of the subject to know if the bone age is advanced or delayed. Certain standardized methods are used to score skeletal maturity, the most common methods are the Tanner-Whitehouse (TW) and Greulich-Pyle (GP) methods. The growth plate comprises a resting zone, a proliferative zone, hypertrophic cartilage zone, calcified cartilage zone, and then the ossification zone. This is the zonal distribution from the epiphysis to the diaphysis. After the closure of growth plates, spinal growth still occurs to some extent, adding up to the final height. The growth plates in boys close at around 17 to 19 years of age, while in girls, they close at around 13 to 15 years.

Marfan syndrome is a disorder that affects the connective tissue in many parts of the body. Connective tissue provides strength and flexibility to structures such as bones, ligaments, muscles, blood vessels, and heart valves. The signs and symptoms of Marfan syndrome vary widely in severity, timing of onset, and rate of progression.This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.At least 25 percent of Marfan syndrome cases result from a new mutation in the FBN1 gene. These cases occur in people with no history of the disorder in their family.The two primary features of Marfan syndrome are vision problems caused by a dislocated lens (ectopia lentis) in one or both eyes and defects in the large blood vessel that distributes blood from the heart to the rest of the body (the aorta).Associations include:Tall statureLearning disability (50%)Lens subluxation (usually upwards)Femoral herniaHemivertebraeCardiac problems (Aortic/mitral regurgitation, aneurysms)Joint hypermobilityArachnodactyly

Among the given options, pituitary adenoma is an acquired anterior pituitary disorder which represent between 10 and 25% of all intracranial neoplasms.Other options:- Agenesis of the corpus callosum is characterised by the partial or complete absence of the corpus callosum. This condition is associated with pituitary hormone deficiencies.- Congenital disorders such as hydrocephalus or arachnoid cysts may be a cause of precocious puberty.- Pituitary hypoplasia and septo-optic dysplasia are congenital disorders of the pituitary gland.

The most probable diagnosis for this patient would be congenital hypertrophic pyloric stenosis.Congenital Hypertrophic Pyloric Stenosis (CHPS):Pyloric stenosis should be ruled out in any baby who presents with a long-term history of vomiting and failure to thrive. Infants typically present with projectile, non-bilious vomiting and are said to be hungry and wanting to feed despite poor weight gain. A blood gas would be helpful in this instance, although the diagnosis can be made more accurately by observing the stenosis during ultrasound. Many infants have symptoms of gastroesophageal reflux disease, although only a small minority are unable to gain weight adequately. A UTI in infants can present with non-specific symptoms, but they might have a fever and can show poor feeding. Malrotation will present with bilious vomiting.The definitive surgical management is the Ramsteadt’s pyloromyotomy.

Based on the clinical scenario, the most probable diagnosis is acute appendicitis.Acute appendicitis presents typically with central abdominal pain migrating to the right iliac fossa, anorexia, nausea and fever. The temperature usually does not go beyond 40C. Although appendicitis is a clinical diagnosis, an ultrasound scan showing an appendix width of greater than 6mm is diagnostic.Pyrexia, guarding, and pain are all in keeping with appendicitis.Other options:- Cholecystitis is very rare in children, and although gall stones are present, there is no jaundice or biliary tree dilatation suggested by the scan.- Impacted Gall Stone: There is no mention of common bile duct dilatation in the clinical scenario.- Sickle Cell Crisis: A sickle cell crisis should not cause guarding, or an ultrasound scan finding of a dilated appendix base.- Gastroenteritis: Gastroenteritis would not produce the ultrasound scan findings described above with a thickened appendix.

A surgeon will observe the patient and will decide which procedure he needs.

Compared to parametric tests, non parametric tests are seen to be less powerful as they often contend with fewer assumptions, and may use less information from the data. Sample sizes can be smaller. The samples do not have to follow a normal distribution as in parametric tests, and data may be ordinal, ranked or contain outliers that cannot be removed. Therefore nonparametric tests are well suited for these instances and do not need to be used as a last resort. They are not any more complex than parametric tests.

Key observations in the results:

1. Oxygen Saturation Step-Up:
   • There is a significant step-up in oxygen saturation from the right ventricle (72%) to the pulmonary artery (86%). This suggests the presence of left-to-right shunting of blood.
2. Pressure Differences:
   • The pressure in the pulmonary artery is elevated (53/13 mmHg), indicating pulmonary hypertension.

Differential Diagnosis:

1. Patent Ductus Arteriosus (PDA):
   • PDA can cause increased pulmonary blood flow, leading to a step-up in oxygen saturation in the pulmonary artery. The pulmonary artery pressures can also be elevated due to increased blood flow.
2. Primary Pulmonary Hypertension:
   • Typically presents with elevated pulmonary pressures but does not usually show a step-up in oxygen saturation.
3. Pulmonary Stenosis:
   • Would result in elevated right ventricular pressure but would not explain the step-up in oxygen saturation.
4. Septum Primum Atrial Septal Defect (ASD):
   • Would result in a step-up in oxygen saturation from the right atrium to the right ventricle, not between the right ventricle and pulmonary artery.
5. Tetralogy of Fallot:
   • Characterized by right ventricular outflow tract obstruction, VSD, right ventricular hypertrophy, and an overriding aorta. Oxygen saturation levels would typically be lower in the systemic circulation.

According to APLS, your next step should be one of the following: synchronous DC shock, amiodarone, or cardiology advice for alternative antiarrhythmics.

At 7 months, children are expected to sit briefly leaning forward on their hands, reach and grasp objects, transfer objects from hand to hand, and babble. Children are usually expected to wave goodbye or grasp objects with their fingers or thumb at around 10 months and older.

A 3-dimensional transoesophageal echocardiography (3D TEE) provides direct visualization of the entire PFO anatomy and surrounding structures. It allows more accurate diagnosis.

The most probable diagnosis for this patient would be Crohn’s disease.Crohn’s disease:An inflammatory bowel disease which can affect any part of the bowel from the mouth to the anus. Symptoms include abdominal pain, diarrhoea, pyrexia and weight loss. Extra-intestinal manifestations include arthritis, uveitis, fatigue, anaemia and rashes including pyoderma gangrenosum and erythema nodosum.Other options:- Anorexia nervosa is an important diagnosis to consider. There are no indicators in the description that she has a fear of gaining weight or a strong desire to be thin.- Diabetic ketoacidosis is incorrect because there is no polydipsia or polyuria. A patient in DKA is more likely to present with vomiting and not diarrhoea.- Recurrent aphthous stomatitis is not a correct answer because it does not explain all of the symptoms described, only the mouth ulcers.- Ulcerative colitis (UC) is also incorrect. UC is a form of inflammatory bowel disease that causes inflammation in the colon. The main symptom is bloody stools, which is not mentioned as a feature in history.