This patient in question is most likely suffering from inflammatory bowel disease, probably ulcerative colitis. The most valuable investigation that can assess the severity and extent of the disease, including the opportunity to obtain biopsies is a colonoscopy.Other options:Barium studies and abdominal x-rays do not give sufficient information. While they can provide indicative evidence, only a colonoscopy-guided biopsy can confirm IBD.Radio-isotope scans will help in identifying a focus such as a Meckel’s diverticulum, and angiography is rarely indicated unless a vascular lesion is suspected of causing the intestinal bleed.

Logistic regression analysis is an easy to use regression that can serve to estimate how a binary or dichotomous dependent variable, for example whether or not a student passes or fails a medical exam, is related to the number of hours the student studies for the exam. This regression is able to yield an odds ratio, i.e. the probability of passing the exam based on each additional hour of study. As stated, the outcome does not need to be normally distributed but is usually binary. This type of analysis is not complex and does not need to be avoided as it is available most statistical packages.

Hydrocephalus is a serious medical condition resulting from excessive accumulation of cerebrospinal fluid in the brain leading to abnormal pressure build-up inside the brain. Hydrocephalus can be categorized into two types according to the flow of CSF between the ventricles. When the CSF flows freely between the ventricles, but is blocked after it exits the ventricular system, the hydrocephalus is said to be a communicating hydrocephalus. When the flow of CSF within the ventricles is blocked, the resulting hydrocephalus is termed as obstructive, or non-communicating. The communicating hydrocephalus is caused by insufficient reabsorption of CSF in the subarachnoid space, which is also observed in cases of bacterial meningitis, in which inflammatory process leads to the thickening of the leptomeninges and thereby reduces CSF reabsorption. Arnold Chiari malformation is associated with obstructive hydrocephalus due to blocked ventricles. Congenital aqueduct stenosis causes the blockage of third and lateral ventricles. Congenital atresia of the foramen of Monro leads to blocked lateral ventricles and thus results in obstructive hydrocephalus. Tumour of the posterior fossa is associated with blockage of the fourth ventricle outflow.

Koebner’s phenomenon describes skin lesions that occur on damaged skin, usually in a linear fashion at the site of injury. Conditions which exhibit true Koebnerisation include psoriasis, lichen planus, lichen sclerosis, vitiligo, Kaposi sarcoma and SLE. Conditions such as erythema nodosum or multiforme, or Lyme disease and Impetigo do not exhibit Koebner’s phenomenon.

Lamotrigine does not significantly increase risk of birth defects during pregnancy.

Intussusception is an urgent condition that must be excluded first as it may lead to life-threatening complications.

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.

When a child does not hear the sound in the middle during Weber test, it means they either they have a conductive hearing loss on the side they hear the sound, or a sensorineural hearing loss on the opposite side. Rinne’s test helps distinguish between the two. In this particular case, the hearing loss is most probably conductive due to the middle ear effusion. Therefore, Weber’s test should be localised to the left and Rinne’s should be positive on the right.

Coverings of the spermatic cord:Spermatic cord is covered by three concentric layers of fasciae, derived from the layers the of anterior abdominal wall. Developmentally, each covering is acquired as the processus vaginalis descends into the scrotum through the layers of the abdominal wall. The layers are:External spermatic fascia: It is derived from the external oblique muscle. It attaches to the margins of superficial inguinal ring.Cremasteric fascia: It is derived from the internal oblique muscle. It covers the cremaster muscle.Internal spermatic fascia: It is derived from the fascia transversalis (fascia covering the transversus abdominis muscle). It is attached to the margins of the deep inguinal ring.

The signs and symptoms of vitamin D-dependent rickets begin within months after birth, and most are the same for all types of the condition. The weak bones often cause bone pain and delayed growth and have a tendency to fracture. When affected children begin to walk, they may develop abnormally curved (bowed) legs because the bones are too weak to bear weight. Impaired bone development also results in widening of the metaphysis, especially in the knees, wrists, and ribs. Some people with vitamin D-dependent rickets have dental abnormalities such as thin tooth enamel and frequent cavities. Poor muscle tone (hypotonia) and muscle weakness are also common in this condition, and some affected individuals develop seizures.

Because of the patient’s history of chronic analgesic use of daily paracetamol intake, the most likely diagnosis of this case is Analgesic misuse headache. In these cases, the headache is only temporarily relieved by analgesics. Treatment involves gradual withdrawal of analgesics.

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.

Cushing reflex is a physiological nervous system response to increased intracranial pressure (ICP) that results in Cushing’s triad of increased blood pressure, irregular breathing, and bradycardia. It is usually seen in the terminal stages of acute head injury and may indicate imminent brain herniation. It can also be seen after the intravenous administration of epinephrine and similar drugs.

All of the presenting features of the child are suggestive raised intracranial pressure. Thus, urgent treatment with 20% Mannitol can improve the child’s condition. Mannitol is an osmotic diuretic that is used in the treatment of raised intracranial pressure. It should be avoided in hypovolaemia because of its diuretic effects. Other options:- Head up at 15°: Keeping the head up at 20° in the midline will aid venous drainage. – Maintain CO2 at 5 kPa: If there is an acute rise in intracranial pressure, then lowering the CO2 to 4–4.5 kPa as a temporary measure can be beneficial. However, this must be only short-lived since it causes vasoconstriction and can impair cerebral blood flow. – 10% glucose bolus: Maintaining normoglycemia in traumatic brain injury is important. – 0.9% saline infusion: Hypertonic saline infusion of 3% can reduce intracranial pressure. 0.9% saline as a bolus could be beneficial if there were hypotension.

The next step in the management of this patient is starting a normal saline fluid bolus, following which we should send samples for blood culture, lactate and C-reactive protein. The patient is probably a case of anorexia nervosa (AN).Note:Children with AN are at higher risk of developing infections, and this needs to be considered in this case. Patients with AN may not respond in the usual fashion to sepsis as they may not mount a fever in response to infection. Hypoglycaemia (especially when severe or persistent despite correction) should raise the alarm for an infection as should tachycardia and cool peripheries. Children with severe AN are more likely to be bradycardic. Therefore, a tachycardia should cause the clinician to consider that another process is going on.Other options:- Correcting electrolyte abnormalities is, of course, very important. However, while these are awaited, one needs to consider that this patient is septic and managed accordingly. Children with anorexia nervosa (AN) may have a whole host of electrolyte abnormalities, some of which can be treated with oral or nutritional supplementation although sometimes intravenous correction is required. Electrolytes need to be checked frequently during admission because of the risk of refeeding syndrome, and dietetic input is required to advise on appropriate starting intake.- While maintenance fluids like dextrose are likely to be needed in this case, consideration needs to be given to the underlying cause of the hypoglycaemia. As the sugar has come up following a glucose bolus, a 10% dextrose infusion would be excessive.- An ECG should form a part of any assessment of a child with AN. In this case, it would not be the first thing| however, as part of the acute management of this child, cardiac monitoring should be commenced. One would usually expect a child with AN to be bradycardic so a tachycardia should raise suspicion that another process is going on.- Dietary input will be vital for this child’s ongoing management. However, their acute issues take precedence in this case. Nevertheless, a dietician should be informed and involved from an early stage.

WHO states that diabetes can be diagnosed from a single fasting glucose of > 7.0 mmol/l with characteristic symptoms or a glucose level of > 11.1 mmol/l 2 hours after a glucose load. Two fasting glucose levels of > 7.0 mmol/l on separate occasions can also fit the diagnosis in the absence of characteristic symptoms.

Intussusception is the invagination of one segment of the intestine within a more distal segment. It presents with vomiting, abdominal pain, and a palpable abdominal mass.Intussusception usually affects infants between 6-18 months old. Boys are affected twice as often as girls

Milestones of 6 monthsSocial and EmotionalKnows familiar faces and begins to know if someone is a stranger Likes to play with others, especially parents Responds to other people’s emotions and often seems happy Likes to look at self in a mirror Language/CommunicationResponds to sounds by making sounds Strings vowels together when babbling (“ah,” “eh,” “oh”) and likes taking turns with the parent while making sounds Responds to own name Makes sounds to show joy and displeasure Begins to say consonant sounds (jabbering with “m,” “b”) Cognitive (learning, thinking, problem-solving)Looks around at things nearby Brings things to mouth Shows curiosity about things and tries to get things that are out of reach Begins to pass things from one hand to the other Movement/Physical DevelopmentRolls over in both directions (front to back, back to front) Begins to sit without support When standing, supports weight on legs and might bounce Rocks back and forth, sometimes crawling backwards before moving forward

The most probable diagnosis for the patient would be DiGeorge syndrome due to 22q11 deletion. It causes embryonic defects of the third and fourth branchial arches. It is sporadic in 90% of cases and 10 % inherited from parents as autosomal dominant.Characterised by distinct facial features (micrognathia, cleft palate, short philtrum, and low-set ears), hypocalcaemia, mental retardation, cardiac defects (especially tetralogy of Fallot), and immune deficiencies.A useful memory aid is CATCH-22:- Cardiac defects- Abnormal facial features- Thymic aplasia/hypoplasia- Cleft palate- Hypocalcaemia/Hypoparathyroidism- 22 – Due to 22q11 deletion

Key Observations:

1. Cyanosis and Low Oxygen Saturation:
   • Central cyanosis indicates mixing of oxygenated and deoxygenated blood.
   • The aortic oxygen saturation is low (76%), indicating a significant amount of deoxygenated blood entering systemic circulation.
2. Pressure Analysis:
   • The right ventricle pressure is significantly elevated (110/6 mmHg), suggesting an obstructive lesion like pulmonary stenosis or an increased volume load due to a shunt.
   • The pulmonary artery pressure is low (20/5 mmHg) despite the high right ventricular pressure, suggesting an obstruction to flow from the right ventricle to the pulmonary artery, consistent with pulmonary stenosis.
3. Oxygen Saturation Analysis:
   • There is a notable drop in oxygen saturation from the left ventricle (87%) to the aorta (76%), indicating a mixture of oxygenated and deoxygenated blood in the systemic circulation, suggestive of a right-to-left shunt.

Differential Diagnosis:

1. Pulmonary Stenosis:
   • Supported by elevated right ventricular pressure and low pulmonary artery pressure.
2. Ventricular Septal Defect (VSD):
   • Would typically cause left-to-right shunting, leading to increased pulmonary blood flow and higher oxygen saturation in the right ventricle and pulmonary artery, which is not observed here.
3. Over-riding Aorta:
   • Seen in conditions like Tetralogy of Fallot where the aorta receives blood from both the right and left ventricles, leading to mixed oxygen saturation.
4. Right-to-Left Shunt:
   • The data indicates a right-to-left shunt, with low oxygen saturation in the aorta, suggesting that deoxygenated blood is bypassing the lungs and entering systemic circulation.
5. Aortic Stenosis:
   • Typically presents with high left ventricular pressure and a pressure gradient between the left ventricle and the aorta, which is not observed here.

Conclusion:

Given the data, the most likely abnormalities present in this patient are Pulmonary Stenosis, Right-to-Left Shunt, and Over-riding Aorta. These findings are consistent with a condition like Tetralogy of Fallot, where all these features are present.

Alpha-fetoprotein (AFP) is a plasma protein produced by the embryonic yolk sac and the fetal liver. AFP levels in serum, amniotic fluid, and urine functions as a screening test for congenital disabilities, chromosomal abnormalities, as well as some other adult occurring tumours and pathologies.Pregnant maternal serum AFP levels are elevated in:- Neural tube defects (e.g., spina bifida, anencephaly)- Omphalocele- Gastroschisis- posterior urethral valves- nephrosis- GI obstruction- teratomas

The most probable diagnosis in this patient would be Friedreich’s ataxia.Friedreich’s ataxia is also called spinocerebellar degeneration. It is an autosomal recessive condition. The onset of ataxia is around ten years of age. Intelligence is preserved. Cerebellar impairment, distal muscle weakness, pes cavus, hammer-toes and progressive kyphoscoliosis are present. Deep tendon reflexes are absent, particularly the ankle jerk. Loss of vibration and position sense occurs because of degeneration of the posterior columns. Hypertrophic cardiomyopathy can occur with progression to congestive cardiac failure.Other options:- Ataxia Telangiectasia: ataxia develops earlier, around two years of age, with loss of ambulation by adolescence. Nystagmus is present. Telangiectasia becomes evident by mid-childhood and is found on bulbar conjunctiva, over the bridge of the nose and on the ears. These children have an increased risk of developing lymphoreticular malignancies.- Abetalipoproteinemia: begins in childhood with steatorrhea and failure to thrive. Neurological symptoms appear in late childhood. These include ataxia, retinitis pigmentosa, peripheral neuritis, abnormalities in position and vibration sense, muscle weakness and mental retardation. Vitamin E is undetectable in serum in these patients.- Acute cerebellar ataxia: occurs in children of 1-3 years of age and is a diagnosis of exclusion. It often follows acute viral infections like varicella, coxsackievirus or echovirus by 2-3 weeks. It is an autoimmune response to a viral agent affecting the cerebellum. Prognosis is excellent with complete recovery present. Very small numbers have long term sequelae like ataxia, incoordination, speech disorder and behavioural problems.- Acute labyrinthitis: It is difficult to differentiate acute labyrinthitis from acute cerebellar ataxia in a toddler. It is associated with middle ear infections, vertigo and vomiting.

The development of the kidney proceeds through a series of successive phases, each marked by the development of a more advanced kidney: the pronephros, mesonephros, and metanephros. The development of the pronephric duct proceeds in a cranial-to-caudal direction. As it elongates caudally, the pronephric duct induces nearby intermediate mesoderm in the thoracolumbar area to become epithelial tubules called mesonephric tubules. Each mesonephric tubule receives a blood supply from a branch of the aorta, ending in a capillary tuft analogous to the glomerulus of the definitive nephron. The mesonephric tubule forms a capsule around the capillary tuft, allowing for filtration of blood. This filtrate flows through the mesonephric tubule and is drained into the continuation of the pronephric duct, now called the mesonephric duct or Wolffian duct. The nephrotomes of the pronephros degenerate while the mesonephric duct extends towards the most caudal end of the embryo, ultimately attaching to the cloaca.

The most probable diagnosis for the patient in question is atrioventricular nodal re-entrant tachycardia (AVNRT).The presenting features of the patient are suggestive of supraventricular tachycardia (SVT). The most common form of SVT in children over 8 years old is atrioventricular nodal re-entrant tachycardia. It occurs as a result of an additional electrical circuit in or near the AV node itself.Other options:- Atrial Flutter: is a form of re-entry tachycardia within the atria which then becomes unsynchronised with the ventricles, which is not the case here. Furthermore, it is most common in babies and children with congenital heart disease.- Atrial tachycardia: is a condition where an area of atrium takes over the pacemaker activity of the heart. However, it is relatively uncommon.- Atrioventricular re-entrant tachycardia (AVRT): occurs due to an accessory electrical pathway between the atria and ventricles forming a re-entry circuit. This is the most common cause of SVT in children < 8 years old. One of the specific diagnoses of AVRT is Wolff-Parkinson-White syndrome. However, WPW syndrome is much rarer than AVNRT.- Premature atrial contractions (PACs): are very common in normal, healthy children and adolescents. Occasionally, they can give rise to the feeling of a 'skipped beat'. Fortunately, they are rarely associated with any significant underlying pathology or need to be treated.

Leiner disease belongs to a heterogeneous group of disorders associated with permanent or temporary complement C5 plasma deficiency. It is a rare disease that follows an autosomal recessive pattern of transmission. It is prevalent in female, breast-fed babies. The hallmark of this syndrome is severe diarrhoea, severe generalized seborrheic dermatitis, central nervous system defects, marked wasting, recurrent local and systemic infections, and failure to thrive.

Diabetes ketoacidosis is one of the most serious and acute complications of diabetes. At the time of presentation and during treatment of diabetic ketoacidosis (DKA), several metabolic and electrolyte derangements can ultimately result in respiratory compromise. Most commonly, hypokalaemia, hypomagnesemia and hypophosphatemia can eventually lead to respiratory muscles failure. Furthermore, tachypnoea, hyperpnea and more severely, Kussmaul breathing pattern can develop. Also, hydrostatic and non-hydrostatic pulmonary oedema can occur secondary to volume shifts into the extracellular space and secondary to increased permeability of the pulmonary capillaries. The presence of respiratory failure in patients with DKA is associated with higher morbidity and mortality. Being familiar with the causes of respiratory compromise in DKA, and how to treat them, may represent better outcomes for patients with DKA.

Idiopathic hypercalciuria (IH) is the commonest metabolic abnormality in patients with calcium kidney stones. It is characterized by normocalcemia, absence of diseases that cause increased urine calcium, and calcium excretion that is above 250 mg/day in women and 300 mg/day in men. Subjects with IH have a generalized increase in calcium turnover, which includes increased gut calcium absorption, decreased renal calcium reabsorption, and a tendency to lose calcium from bone. Despite the increase in intestinal calcium absorption, negative calcium balance is commonly seen in balance studies, especially on a low calcium diet. The mediator of decreased renal calcium reabsorption is not clear| it is not associated with either an increase in filtered load of calcium or altered PTH levels. There is an increased incidence of hypercalciuria in first-degree relatives of those with IH, but IH appears to be a complex polygenic trait with a large contribution from diet to expression of increased calcium excretion. Increased tissue vitamin D response may be responsible for the manifestations of IH in at least some patients.

The injury described in question leads to an abnormal communication between the orbit and the ipsilateral maxillary sinus – this is termed as a blow-out fracture of the orbit.The maxillary sinuses are found in the maxillary bone, inferior to the orbit. They are the largest of the paranasal air sinuses. The maxillary bone forms the floor of the orbit. This layer of bone separates the orbit from the maxillary sinus. As such, fractures of the floor of the orbit can be associated with herniation of the orbital contents into the maxillary sinus. Other options:- The ethmoidal air cells are a collection of smaller air cells in the ethmoid bone. They lie lateral to the anterior superior nasal cavity. They are separated from the orbit by a very thin plate of ethmoid bone called the lamina papyracea, which is found on the medial wall of the orbit. The thin nature of this bone means it is commonly fractured in orbital trauma. However, this is the incorrect answer to the above question as a communication between the ethmoidal air cells, and the orbit is associated with fractures of the medial wall of the orbit, not the floor. – The frontal sinuses are found in the frontal bones, above the orbits on each side of the head. A large portion of the roof of the orbit is composed of the frontal bone and separates the orbit from the frontal sinus. Fractures of the roof of the orbit can be associated with communication between the frontal sinus and orbit. The frontal bones are strong, and so fracture is associated with high-impact anterior trauma, such as a road traffic accident. – The sphenoid sinuses are found in the posterior portion of the roof of the nasal cavity. The pituitary gland lies nestled within the hypophyseal fossa, with only a thin wall of bone separating it from the sphenoid sinus below. As such, neurosurgeons can gain access to the pituitary gland via the sphenoid sinus, in a procedure called transsphenoidal hypophysectomy. – The nasal cavity extends from the nares to the nasopharynx. It is found more medial and inferior than the orbits. It does not lie adjacent to the orbit at any point and so is unlikely to be involved in an orbital fracture.

Wolff-Parkinson-White (WPW) syndrome is a pre-excitation syndrome characterised by re-entry tachycardia that most commonly presents as a recurrent supraventricular tachycardia. ECG will show a short PR interval and a prolonged QRS complex.

The peroneus brevis muscle originates from the lower two-thirds of the lateral body of the fibula and has inserts at the base of the fifth metatarsal. Fractures to this bone are common and can be due to infection, trauma, overuse and repetitive use.