Answer: Inflammatory bowel diseaseThe inflammatory bowel diseases (IBDs), including ulcerative colitis and Crohn disease, are chronic inflammatory disorders of the gastrointestinal tract most often diagnosed in adolescence and young adulthood, with a rising incidence in paediatric populations. Inflammatory bowel disease is caused by a dysregulated mucosal immune response to the intestinal microflora in genetically predisposed hosts. Although children can present with the classic symptoms of weight loss, abdominal pain, and bloody diarrhoea, many present with nonclassical symptoms of isolated poor growth, anaemia, or other extraintestinal manifestations.Colorectal Carcinoma (CRC) is rare in patients less than 20 years of age.

E. coli accounts for the majority of UTI’s in children. If this child responds well to treatment and has no recurrence of his symptoms, then no form of imaging is required, as per NICE advice for children aged 6 months to 3 years. Had the child been less than 6 months of age, then a USS at 6 weeks would be necessary.Other options:- Pseudomonas causes atypical UTI. This warrants ultrasonography within the acute illness phase as it may reflect an underlying pathology and DMSA at 4-6 months.- Recurrent UTI is defined as two or more episodes of pyelonephritis OR 1 pyelonephritis and one cystitis OR 3 or more cystitis. It requires USS at six weeks and DMSA at 4-6 months.- Septicaemia is a sign of an atypical UTI. This requires USS within the acute illness as it may reflect an underlying pathology and DMSA at 4-6 months.- Unwell 48hrs post antibiotics is a sign of an atypical UTI. This requires USS within the acute illness as may reflect underlying pathology and DMSA at 4-6 months.

Projectile vomiting is the hallmark symptom of hypertrophic pyloric stenosis. It is the most common cause of intestinal obstruction in infancy, which has a male-to-female predominance of 4-5:1. Current management recommendations include ultrasonography for diagnosis, correction of electrolytes, and surgical intervention.

Colonic Polyposis and neoplasia are often seen in Cowden Syndrome which is a hamartomatous polyposis syndrome. Patients with Cowden syndrome have an increased risk for colorectal cancer.

Tooth extraction or any surgical procedure may introduce bacteria into the blood stream. The most commonly involved organisms include Staphylococcus aureus and Streptococcus viridans. Once in the blood, these organisms have a very high tendency of attaching to the walls of the heart and causing inflammation known as endocarditis.

The inferior alveolar nerve supplies all the teeth of the respective hemimandible. It transverses the inferior alveolar canal and is a branch of the trigeminal nerve’s mandibular division. Therefore, in this case, the teeth of the right hemimandible will be numb.

Answer: Curling’s ulcersCurling’s ulcer is an acute gastric erosion resulting as a complication from severe burns when reduced plasma volume leads to ischemia and cell necrosis (sloughing) of the gastric mucosa. The most common mode of presentation of stress ulcer is the onset of acute upper GI bleed like hematemesis or melena in a patient with the acute critical illness. A similar condition involving elevated intracranial pressure is known as Cushing’s ulcer. Cushing’s ulcer is a gastro-duodenal ulcer produced by elevated intracranial pressure caused by an intracranial tumour, head injury or other space-occupying lesions. The ulcer, usually single and deep, may involve the oesophagus, stomach, and duodenum. Increased intracranial pressure may affect different areas of the hypothalamic nuclei or brainstem leading to overstimulation of the vagus nerve or paralysis of the sympathetic system. Both of these circumstances increase secretion of gastric acid and the likelihood of ulceration of gastro-duodenal mucosa.Mallory-Weiss syndrome is characterized by upper gastrointestinal bleeding secondary to longitudinal mucosal lacerations (known as Mallory-Weiss tears) at the gastroesophageal junction or gastric cardia. However, Mallory-Weiss syndrome may occur after any event that provokes a sudden rise in the intragastric pressure or gastric prolapse into the oesophagus, including antecedent transoesophageal echocardiography. Precipitating factors include retching, vomiting, straining, hiccupping, coughing, primal scream therapy, blunt abdominal trauma, and cardiopulmonary resuscitation. In a few cases, no apparent precipitating factor can be identified. One study reported that 25% of patients had no identifiable risk factors.

Point mutations are the type of mutations in which only a single nucleotide of the DNA is either deleted, substituted or a new single nucleotide is inserted into the DNA, causing alterations in the original normal DNA sequencing. The examples of point mutations include hemochromatosis, sickle cell disease, and Tay-Sach’s disease. Huntington’s disease is a trinucleotide repeat disorder. Down’s syndrome is characterized by an extra copy of chromosome 21, while Klinefelter syndrome is marked by an extra X chromosome. Fragile X syndrome is also a trinucleotide repeat disorder.

Thyroglossal cyst is the most common congenital thyroid anomaly which is clinically significant and affects women more than men. It is a vestigial remnant of developing thyroid. Although the thyroglossal cyst can develop anywhere along the thyroglossal duct, the most common site is in the midline between the isthmus of thyroid and hyoid bone, or just above the hyoid. Thyroglossal cysts are also associated with ectopic thyroid tissue. Clinically, the cyst moves upward with protrusion of the tongue. Rarely, the persistent duct can become malignant (thyroglossal duct carcinoma) where the cancerous cells arise in the ectopic thyroid tissue that are deposited along the duct. Exposure to radiation is a predisposing factor.

Inhaled objects are more likely to enter the right lung for several reasons. First the right bronchus is shorter, wider and more vertical than the left bronchus. Also, the carina (a ridge-like structure at the point of tracheal bifurcation) is set a little towards the left. The terminal bronchiole is a very small space and impossible for the seed to lodge here.

Oesophageal atresia refers to a congenitally interrupted oesophagus. One or more fistulae may be present between the malformed oesophagus and the trachea. The lack of oesophageal patency prevents swallowing. In addition to preventing normal feeding, this problem may cause infants to aspirate and literally drown in their own saliva, which quickly overflows the upper pouch of the obstructed oesophagus. If a tracheoesophageal fistula (TEF) is present, fluid (either saliva from above or gastric secretions from below) may flow directly into the tracheobronchial tree.The complete absence of gas in the GI tract denotes the absence of a distal tracheoesophageal fistula (TEF)| however, distal fistulae simply occluded by mucous plugs have been rarely reported.If no distal TEF is present, a gastrostomy may be created. In such cases, the stomach is small, and laparotomy is required. In all cases of oesophageal atresia in which a gastrostomy is created, care should be taken to place it near the lesser curvature to avoid damaging the greater curvature, which can be used in the formation of an oesophageal substitute. When a baby is ventilated with high pressures, the gastrostomy may offer a route of decreased resistance, causing the ventilation gases to flow through the distal fistula and out the gastrostomy site. This condition may complicate the use of ventilation.

Based on the clinical scenario provided, the most probable nerve injured in this patient would be the trochlear nerve. The trochlear nerve has a relatively long intracranial course, and this makes it vulnerable to injury in head trauma. Head trauma is the most frequent cause of acute fourth nerve palsy. A 4th nerve palsy is the most common cause of vertical diplopia. The diplopia is at its worst when the eye looks medially which it usually does as part of the accommodation reflex when walking downstairs.

Among the treatment options provided, the most appropriate would be prednisolone 1-2 mg/kg.Other options:- Dexamethasone 0.15 mg per kg is the correct dose based on new trials and BNF guidance.- Inhaled budesonide 2mg would be a more appropriate dose.- Nebulised adrenaline may also be used.Croup:Laryngotracheobronchitis caused most commonly by parainfluenza virus. It most commonly affects children between 6 months to 3 years.Seasonal peaks: Most prevalent in autumn and spring.It starts as viral URTI then progresses to barking cough and a hoarse cry. Stridor and respiratory distress may occur. The illness can last from two days to 2 weeks.Relevant differential diagnoses include epiglottitis (the child will be septic with high temp and drooling) and inhaled foreign body.All children with moderate/severe croup should be given one dose of oral dexamethasone.Further doses may be needed if children have rebound symptoms.

The most worrying condition is testicular torsion and to exclude it exploratory surgery is required.

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.

Diffuse proliferative glomerulonephritis is a term used to describe a distinct histologic form of glomerulonephritis common to various types of systemic inflammatory diseases, including autoimmune disorders (e.g., systemic lupus erythematosus [SLE]), vasculitis syndromes (e.g., granulomatosis with polyangiitis), and infectious processes. In DPGN, more than 50% of the glomeruli (diffuse) show an increase in mesangial, epithelial, endothelial (proliferative), and inflammatory cells (i.e., glomerulonephritis).

The most common physiological factors that influence renin secretion include renal perfusion pressure, renal sympathetic nerve activity, and tubular sodium chloride load.The perfusion pressure in the renal artery is the most profound parameter to influence renin secretion| when the renal perfusion pressure falls (i.e. hypovolaemia), renin secretion rises, and vice versa.

In the final result of this double blind study, 25% or one in four of patients who received the treatment responded positively. Though the difference is significant at P<0.05, it is better to present this as a significant difference at 0.4%. The number needed to treat (NNT) is defined as the inverse of the absolute risk reduction. Taking this as 0.25 (25%), the NNT is 1/0.25 = 4. However given the 95% confidence interval is between 10-50% for absolute risk reduction, the NNT with 95% CI is between 2 and 10. Therefore we cannot say with certainty that the NNT is at least 4.

The patient history suggests a spontaneous tension pneumothorax which is a life-threatening situation in which excess air is introduced into the pleural space surrounding the lung. When there is a significant amount of air trapped in the pleural cavity, the increasing pressure from this abnormal air causes the lung to shrink and collapse, leading to respiratory distress. This pressure also pushes the mediastinum (including the heart and great vessels) away from its central position, e.g. deviated trachea, and diminishing the cardiac output. Tension pneumothoraxes cause chest pain, extreme shortness of breath, respiratory failure, hypoxia, tachycardia, and hypotension. These are definitively managed by insertion of a chest tube. However, in the emergency setting temporizing measures are needed while chest tube materials are being gathered. In these situations, urgent needle thoracostomy (also called needle decompression) is performed.

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.

The accuracy of the test for calcium levels in the blood is affected by the blood level of albumin. If albumin levels are low, the calcium level can also appear low.This is termed as pseudohypocalcemia.Hypocalcaemia usually presents with muscle spams. These can include spasms of voluntary muscle but also smooth muscle such as in the airways (causing bronchospasm) and in the heart (causing angina).

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.

Haemophilia A and haemophilia B are inherited in an X-linked recessive pattern. The genes associated with these conditions are located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition.

There are two lateral rotators of the arm, the infraspinatus and the teres minor muscles. The infraspinatus muscle receives nerve supply from C5 and C6 via the suprascapular nerve, whilst the teres minor is supplied by C5 via the axillary nerve.

External oblique forms the outermost muscle of the three muscles comprising the anterolateral aspect of the abdominal wall. Its aponeurosis comprises the anterior wall of the inguinal canal.

Adenoid tissue sometimes swell as a result of fighting off the infection as germs are trapped in the adenoids. Adenoid enlargement is suspected.

Haemolytic uremic syndrome belongs to a heterogeneous group of disorders characterized by a triad of thrombocytopenia, microangiopathic haemolytic anaemia, and acute kidney injury. It is one of the most common causes of renal injury in children. The clinical findings are due to thrombotic microangiopathy, which leads to arterioles and capillary wall thickening along with endothelial swelling and detachment. The significant laboratory findings include increased white cell count, raised serum urea and creatinine, increased serum LDH, decreased platelet count, haematuria, and proteinuria.

Jacob is likely to be four years old as demonstrated by his activities throughout the day. Most 4 year olds are able to run well, jump and hop, but find skipping a little more difficult. They are able to brush their teeth and dress themselves with supervision, and go to the toilet alone.

Based on the clinical scenario provided, the most probable diagnosis for this patient would be tuberous sclerosis which is an autosomal dominant condition.Among the options provided, only Neurofibromatosis Type 1 is inherited by an autosomal dominant pattern. Other options:- Beckwith-Wiedemann syndrome is an example of an imprinting disorder and results from abnormalities of inheritance or methylation of chromosome 11p15.- Cystic fibrosis is an autosomal recessive condition.- Duchenne Muscular Dystrophy is an example of an X-linked recessive condition.- Hypophosphataemic (Vitamin D resistant) rickets is an X-linked dominant condition.

Findings described are suggestive of Waterhouse-Friderichsen syndrome which develops secondary to meningococcaemia. The reported incidence of Addison’s disease is 4 in 100,000. It affects both sexes equally and is seen in all age groups. It tends to show clinical symptoms at the time of metabolic stress or trauma. The symptoms are precipitated by acute infections, trauma, surgery or sodium loss due to excessive perspiration.