NICE guidelines suggest that when a child’s single risk factor is 2 vomits, the child should be observed for 4 hours from the time of the injury, instead of having a CT.

The most likely causative organism for the symptoms of this child is Giardia lamblia.Giardiasis results in fat malabsorption thus giving rise to greasy stools. It is resistant to chlorination, hence has a risk of transfer in swimming pools.World Health Organisation definitions- Diarrhoea: > 3 loose or watery stool per day- Acute diarrhoea < 14 days- Chronic diarrhoea > 14 daysConditions that usually present as acute diarrhoea:- Gastroenteritis: It may be accompanied by abdominal pain or nausea/vomiting.- Antibiotic therapy: Can occur following antibiotic therapy, especially common with broad spectrum antibiotics.Conditions that usually present as chronic diarrhoea:- Irritable bowel syndrome: It is a very common disease.The most consistent features are abdominal pain, bloating and change in bowel habit. Patients may be divided into those with diarrhoea predominant IBS and those with constipation-predominant IBS.Features such as lethargy, nausea, backache and bladder symptoms may also be present in these patients.- Ulcerative colitis: It presents as bloody diarrhoea. Patients can also present with crampy abdominal pain and weight loss. Faecal urgency and tenesmus may be seen.- Crohn’s disease: It is also associated with crampy abdominal pains and diarrhoea. Bloody diarrhoea less common than in ulcerative colitis. Other features include malabsorption, mouth ulcers perianal disease and intestinal obstruction – Colorectal cancer: It is very rare in children. The symptoms depend on the site of the lesion but include diarrhoea, rectal bleeding, anaemia and constitutional symptoms like weight loss and anorexia.- Coeliac disease: In children, it may present with failure to thrive, diarrhoea and abdominal distension.Other conditions associated with diarrhoea include thyrotoxicosis, laxative abuse, appendicitis, and radiation enteritis.

Cow’s milk differs in composition to human breast milk. The sodium content of cows milk is too high, which can easily overwhelm a baby’s developing kidneys and lead to hypernatremia and dehydration. In addition to its iron content being too low, cows milk can cause further increase iron deficiency anaemia by irritating the baby’s intestinal lumen and causing blood loss per rectum. After 12 months a baby’s gastrointestinal tract and organs are able to tolerate cows milk.

Polycythaemia is a commonly occurring neonatal disorder, which is characterized by a venous haematocrit ≥ 65%. It increases the blood viscosity and causes microcirculatory flow impairment in the end-organs. Causes of polycythaemia are multi-factorial, but the significant risk factors are maternal diabetes, SGA, LGA or post-term birth, infants with chromosomal abnormalities, and delayed clamping of the cord. Jaundice is not a recognized risk factor for polycythaemia.

Ideally, the test is done in the first 4 to 5 weeks, but it can be done at up to 3 months of age.The identification of all new-borns with hearing loss before age 6 months has now become an attainable realistic goal. In the past, parents and paediatricians often did not suspect a hearing loss until the age of 2-3 years, after important speech and language milestones have not been met. By the time these milestones are missed, the hearing-impaired child has already experienced irreversible delays in speech and language development.

Removal of foreign bodies from the ear is indicated whenever a well-visualized foreign body is identified in the external auditory canal. Insects are better extracted with suction than with forceps or hooks. From the given answers, irrigation with warm water is the most suitable answer.

HELLP syndrome is a complication of pregnancy characterized by haemolysis, elevated liver enzymes, and a low platelet count. It usually begins during the last three months of pregnancy or shortly after childbirth. HELLP syndrome is a life-threatening condition that can potentially complicate pregnancy. It is named for 3 features of the condition: Haemolysis, Elevated Liver enzyme levels, and Low Platelet levels. It typically occurs in the last 3 months of pregnancy (the third trimester) but can also start soon after delivery. A wide range of non-specific symptoms may be present in women with HELLP syndrome. Symptoms may include fatigue| malaise| fluid retention and excess weight gain| headache| nausea and vomiting| pain in the upper right or middle of the abdomen| blurry vision| and rarely, nosebleed or seizures. The cause of HELLP syndrome is not known, but certain risk factors have been associated with the condition. It is most common in women with preeclampsia or eclampsia. If not diagnosed and treated quickly, HELLP syndrome can lead to serious complications for the mother and baby. The main treatment is to deliver the baby as soon as possible, even if premature, if there is distress of the mother or the baby. Treatment may also include medications needed for the mother or baby, and blood transfusion for severe bleeding problems.

The chance of having appendicitis again after appendix mass is around 17% in children. While the traditional teachings by Hamilton Bailey recommend following the conservative Ochsner-Sherren regimen followed by an interval appendicectomy six weeks after the discharge of the patient, there remains a looming controversy whether to perform an interval appendicectomy or not.

The baby needs more oxygen saturation which could be attempted by increasing the mean airway pressureAfter initial resuscitation and stabilization, the following should be the ventilator settings used:Rate: 30-40/minutePeak inspiratory pressure (PIP) – determined by adequate chest wall movement.An infant weighing less than 1500 grams: 16-28 cm H2O.An infant weighing greater than 1500 grams: 20-30 cm H2O. Positive end expiratory pressure (PEEP): 4 cm of H2O OR 5-6 cm if FiO2 > 0.90.FiO2: 0.4 to 1.0, depending on the clinical situation.Inspiratory time: 0.3-0.5 sec.After 15 to 30 minutes, check arterial blood gases and pH.If the PaO2 or the O2 saturation is below accepted standards, the FiO2 can be raised to a maximum of 1.0. If the PaO2 or O2 saturation is still inadequate, the mean airway pressure can be raised by increasing either the PIP, PEEP, inspiratory time or the rate, leaving inspiratory time constant.If the PaCO2 is elevated, the rate or peak inspiratory pressure can be raised.

The most probable diagnosis for this patient would be a duplex kidney with an ectopic ureter inserting below the bladder neck. Rationale: The Weigert-Myer law states that the upper moiety ureter inserts inferior and medial to the lower moiety ureter. Other options:- Horseshoe kidney would display as a single pelvic kidney on an ultrasound scan.- Ureterocele would be a cystic lesion within the bladder or may prolapse at birth. – Continence should not be affected by polycystic kidney disease. – The overactive bladder would cause frequency and urgency, neither of which is mentioned in the history.

Prevalence:

This is the proportion of individuals in a population who have a specific condition, disease, or attribute at a given point in time or over a specific period.

Incidence:

This is the number of new cases of a specific condition, disease, or attribute that develop in a population during a specified period of time.

Specificity:

This refers to the ability of a test to correctly identify those without the condition (true negative rate).

Sensitivity:

This refers to the ability of a test to correctly identify those with the condition (true positive rate).

Probability:

This is a measure of the likelihood that an event will occur. In the context of diseases, it can refer to the likelihood of developing a condition.

In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46. Twenty-two of these pairs, called autosomes, look the same in both males and females. The 23rd pair, the sex chromosomes, differ between males and females. Females have two copies of the X chromosome, while males have one X and one Y chromosome.

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.

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 differentials of the child’s condition are likely to include an Iron deficiency anaemia, or a hemoglobinopathy such as sickle cell disease or thalassemia based on the presentation of pallor, growth failure and easy fatiguability. While the full blood count and film present a hypochromic microcytic anaemia with reticulocytosis, the normal serum ferritin levels rule out iron deficiency anaemia. Thalassemia is to be suspected over sickle cell disease as the patient comes from the Mediterranean region known for a high incidence of thalassemia. Sickle cell anaemia also tends to present with normocytic normochromic red blood cells, with many sickled cells. Vitamin B12 deficiency and Aplastic anaemia are ruled out as they present with a macrocytic anaemia, and a decrease in white blood cells, platelets and red blood cells respectively.

Maternal and fetal toxoplasma infection may be avoided by advising pregnant women to wear gloves when gardening or handling cat litter and to cook meat thoroughly. Affected babies are treated with pyrimethamine, sulfadiazine, and folic acid.

6 month old milestones:Social and Emotional:Knows 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/Communication:Responds to sounds by making sounds Strings vowels together when babbling (“ah,” “eh,” “oh”) and likes taking turns with 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 Development:Rolls 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

This is the clinical picture of dermatitis herpetiformis associated with gluten-sensitive enteropathy. To establish the diagnosis, you should measure the coeliac antibodies. Darrier’s sign (where the skin urticates when it is stroked) is positive in urticaria pigmentosa.

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.

Erythema multiforme lesions typically heal without scarring. Other options:- In erythema multiforme, lesions are typically symmetrical and acral, i.e. on the hands, feet and limbs. – HSV is a common cause of erythema multiforme in children, accounting for at least 50% of cases| the lesions typically have damaged skin in the centre and are dusky and bullous (in contrast to urticaria, where the centre of the lesion is normal).

Lichen sclerosus is a common chronic skin disorder that most often affects genital and perianal areas. LS typically presents with vulval itching and clinical findings of pallor, epidermal atrophy (cigarette paper wrinkling), purpura, and/or erosions.Lichen sclerosus (LS) and lichen planus (LP) are both immunologically mediated diseases with a preference for the genitalia. The main difference between the two conditions is that LP has a propensity to involve the mucous membranes including the mouth and vagina which are rarely affected in LS.

The trisomy 18 syndrome, also known as Edwards syndrome, is a common chromosomal disorder due to the presence of an extra chromosome 18, either full, mosaic trisomy, or partial trisomy 18q. The condition is the second most common autosomal trisomy syndrome after trisomy 21.Currently, most cases of trisomy 18 are prenatally diagnosed, based on screening by maternal age, maternal serum marker screening, or detection of sonographic abnormalities (e.g., increased nuchal translucency thickness, growth retardation, choroid plexus cyst, overlapping of fingers, and congenital heart defects ).The main clinical features include prenatal growth deficiency, characteristic craniofacial features (dolichocephaly, short palpebral fissures, micrognathia external anomalies of the ears, and redundant skin at the back of the neck), distinctive hand posture (overriding fingers: index finger overlapping the third and 5th finger overlapping the 4th), nail hypoplasia, short hallux, underdeveloped thumbs, short sternum, and club feet and major malformations (particularly involving the heart).

The autosomal dominant pattern of inheritance involves the presence of at least one of the defected copies of the gene in an individual to develop a specific diseased condition. Examples of this mode of inheritance include myotonic dystrophy, neurofibromatosis, achondroplasia, etc. Still’s disease, also called juvenile idiopathic arthritis, is not a heritable disease. Tay-Sachs disease is an autosomal recessive disease., while spinocerebellar ataxia and Friedreich’s ataxia are caused by trinucleotide repeat expansion.

Congenital hypertrophy of the retinal pigment epithelium is one of FAP’s extra-intestinal manifestations. It appears in early childhood and affects an estimated 90% of those with FAP.

Among the options provided, an 8-week-old full-term infant with normal developmental milestones will smile in response to appropriate stimuli.Rationale:Smiles in response to appropriate stimuli are seen from around 6 weeks of age. A social smile, where the infant has an awareness that a smile attracts attention, is not observed until around 3 months of age.Other options:- At 6 weeks an infant is able to follow objects in the horizontal plane through 90 deg| fixing and following an object through 180 deg in the horizontal plane is a milestone achieved at 3 months, as is pushing up onto forearms. – Pushing up onto hands occurs by around 5 months.- Infants of 3 months should startle to a 60 dB sound.

Erythema nodosum is the most common type of inflammation of the subcutaneous fat tissue, referred to as panniculitis. Erythema nodosum appears as painful, erythematous round lumps, usually symmetrically on the anterior aspect of lower extremities. These lesions are self-limiting and tend to resolve within 2-8 weeks without undergoing necrosis. There are various causes of erythema nodosum, but the most important among children is the streptococcal throat infection. Other causes include autoimmune conditions like sarcoidosis, inflammatory bowel disease, mycobacterial infection (TB), and drugs like penicillin and sulphonamides. Coeliac disease is not linked with the formation of erythema nodosum.

Maternal and fetal toxoplasma infection may be avoided by advising pregnant women to wear gloves when gardening or handling cat litter and to cook meat thoroughly. Affected babies are treated with pyrimethamine, sulfadiazine, and folic acid.

The x-ray is suggestive of bronchiectasis. The most probable aetiology especially considering recurrent chest infections at such a young age is cystic fibrosis.

Fragile X syndrome is a genetic condition that causes a range of developmental problems including learning disabilities and cognitive impairment. Usually, males are more severely affected by this disorder than females.Affected individuals usually have delayed development of speech and language by age 2. Most males with fragile X syndrome have mild to moderate intellectual disability, while about one-third of affected females are intellectually disabled. Children with fragile X syndrome may also have anxiety and hyperactive behaviour such as fidgeting or impulsive actions. They may have attention deficit disorder (ADD), which includes an impaired ability to maintain attention and difficulty focusing on specific tasks. About one-third of individuals with fragile X syndrome have features of autism spectrum disorder that affect communication and social interaction. Seizures occur in about 15 percent of males and about 5 percent of females with fragile X syndrome.Most males and about half of females with fragile X syndrome have characteristic physical features that become more apparent with age. These features include a long and narrow face, large ears, a prominent jaw and forehead, unusually flexible fingers, flat feet, and in males, enlarged testicles (macroorchidism) after puberty.

Absence seizures are induced by over breathing or hyperventilation, while the other features suggest partial seizures.