Relative risk is the probability of an outcome occurring in an exposed group as compared to the probability of that outcome in an unexposed group. In the scenario given, 50% of the children exposed developed the disease while only 10% of the children who were unexposed developed the disease. The relative risk was therefore 50/10=5. There is no further information about whether the study was controlled, the confidence interval, or the type of study. It therefore cannot be confirmed whether the chemical is causative and if it should be avoided.

CSF is produced mainly by a structure called the choroid plexus in the lateral, third and fourth ventricles. CSF flows from the lateral ventricle to the third ventricle through the interventricular foramen (also called the foramen of Monro). The third ventricle and fourth ventricle are connected to each other by the cerebral aqueduct (also called the Aqueduct of Sylvius). CSF then flows into the subarachnoid space through the foramina of Luschka (there are two of these) and the foramen of Magendie (only one of these).Absorption of the CSF into the blood stream takes place in the superior sagittal sinus through structures called arachnoid villi . When the CSF pressure is greater than the venous pressure, CSF will flow into the blood stream.

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.

A minority of affected individuals may experience severe liver failure. This happens most frequently in people with Wilson’s disease during adolescence and more commonly in women. These individuals may rapidly develop signs and symptoms of liver disease, often associated with anaemia due to breakdown of red blood cells (haemolysis) and mental confusion. In some patients, liver disease does not reveal itself, and the patient develops neurologic (brain-related) symptoms. Common neurological symptoms of Wilson disease that may appear and progress with time include tremor, involuntary movements, difficulty swallowing (dysphagia), difficulty speaking and poor articulation (dysarthria), lack of coordination, spasticity, dystonic postures, and muscle rigidity. Almost all affected individuals with the neurological symptoms of Wilson’s disease have Kayser-Fleischer rings in their eyes that can be identified by a slit lamp examination.

Fitz-Hugh-Curtis syndrome (FHCS), or perihepatitis, is a chronic manifestation of pelvic inflammatory disease (PID). It is described as an inflammation of the liver capsule, without the involvement of the liver parenchyma, with adhesion formation accompanied by right upper quadrant pain. A final diagnosis can be made through laparoscopy or laparotomy via direct visualization of violin string-like adhesions or through hepatic capsular biopsy and culture. FHCS is a complication of PID. Microorganisms associated with PID are thought to spread in one of three ways:-Through spontaneous ascending infection, microbes from the cervix or vagina travel to the endometrium, through the fallopian tubes, and into the peritoneal cavity. Complications include endometritis, salpingitis, tubo-ovarian abscess, pelvic peritonitis, and perihepatitis.-Microbes can also spread via lymphatic channels such as an infection of the parametrium from an intrauterine device.-Finally, the hematogenous spread is also possible such as with tuberculosis.

The most appropriate imaging modalities to be used in this child would be CT Head, C-spine and Abdomen/Pelvis and chest X-ray (CXR).The C-spine cannot be cleared, this alongside a multi-trauma presentation means a CT C-spine is indicated rather than X-rays alone. The imaging modality for blunt trauma to the chest is CXR| if this shows significant thoracic trauma, a CT chest should be considered. Other options:- CT Head and Abdomen/Pelvis with CXR and X-ray C-spine: This child is at risk of C-Spine injury following the mechanism of trauma. He had a reduced GCS, has undergone a multi-region trauma and is now intubated. NICE head injury guidelines, therefore, recommend using CT.- CT Head, C-spine and Abdomen/Pelvis X-rays: Imaging of the chest is required following blunt trauma and for endotracheal tube position.- MRI Head: If there were concerns of abnormal neurology, then spinal MRI could be considered.- Whole-body CT: It is not recommended in children in view of the high radiation doses.

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

HLA-DR (3 and 4) have been associated with an increased risk for idiopathic diabetes mellitus.Type 1 diabetes has a high heritability compared to type 2Identical twins have a 30-50% risk if their twin has type 1 diabetes

Incontinentia pigmenti is a genetic condition that affects females more than males. It usually manifests in the skin but can affect other parts of the body as well. It presents with a blistering rash that may evolve into wart-like growths. Hyperpigmentation and hair loss are also present, as well as eye and teeth abnormalities. Clinically there are three phases: 1- the bullous phase – crops of vesicles appear in the first 2 weeks of life|2- the papular phase – warty papules that flatten out over the skin| and 3- the hyperpigmented phase – pigmentary changes in the form of whorls and streaks that are hypo- and hyperpigmented in nature.

Hyperkalaemia is not to evaluate or detect AKI but rather the result of it. If one of the rest of the options is present, then AKI would be suspected.

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.

The most common congenital cyanotic heart disease and the most common cause of blue baby syndrome, Tetralogy of Fallot shows four cardiac malformations occurring together. These are ventricular septal defect (VSD), pulmonary stenosis (right ventricular outflow obstruction), overriding aorta (degree of which is variable), and right ventricular hypertrophy. The primary determinant of severity of disease is the degree of pulmonary stenosis. Tetralogy of Fallot is seen in 3-6 per 10,000 births and is responsible for 5-7% congenital heart defects, with slightly higher incidence in males. It has also been associated with chromosome 22 deletions and DiGeorge syndrome. It gives rise to right-to-left shunt leading to poor oxygenation of blood. Primary symptom is low oxygen saturation in the blood with or without cyanosis at birth of within first year of life. Affected children ay develop acute severe cyanosis or ‘tet spells’ (sudden, marked increase in cyanosis, with syncope, and may result in hypoxic brain injury and death). Other symptoms include heart murmur, failure to gain weight, poor development, clubbing, dyspnoea on exertion and polycythaemia. Chest X-ray reveals characteristic coeur-en-sabot (boot-shaped) appearance of the heart. Treatment consists of immediate care for cyanotic spells and Blalock–Taussig shunt (BT shunt) followed by corrective surgery.

Cystic fibrosis is a life-threatening disorder that causes the build up of thick mucus in the lungs, digestive tract, and other areas of the body. It is a hereditary autosomal-recessive disease caused by mutations of the CFTR gene. Cystic fibrosis eventually results in bronchiectasis which is defined as a permanent dilatation and obstruction of bronchi or bronchioles.

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.

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.

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.

Generally, bed-wetting before age 7 isn’t a concern as the child may still be developing night-time bladder control. The child is less than 5 years and most children will outgrow bed-wetting on their own. Therefore only reassurance and behavioural therapy are suggested at this stage.

Dandy-Walker syndrome is characterised by symptoms of brain maldevelopment that are seen in this patient. A large cranium indicates hydrocephalus, and the hypotonia indicates poor limb development.

Answer: Acute Epstein Barr virus infectionThe Epstein–Barr virus is one of eight known human herpesvirus types in the herpes family, and is one of the most common viruses in humans. Infection with Epstein-Barr virus (EBV) is common and usually occurs in childhood or early adulthood.EBV is the cause of infectious mononucleosis, an illness associated with symptoms and signs like:fever,fatigue,swollen tonsils,headache, andsweats,sore throat,swollen lymph nodes in the neck, andsometimes an enlarged spleen.Although EBV can cause mononucleosis, not everyone infected with the virus will get mononucleosis. White blood cells called B cells are the primary targets of EBV infection.Petechiae on the palate are characteristic of streptococcal pharyngitis but also can be seen in Epstein–Barr virus infection, Arcanobacterium haemolyticum pharyngitis, rubella, roseola, viral haemorrhagic fevers, thrombocytopenia, and palatal trauma.

Pityriasis rosea is a common, acute exanthem of uncertain aetiology. Viral and bacterial causes have been sought, but convincing answers have not yet been found. Pityriasis rosea typically affects children and young adults. It is characterized by an initial herald patch, followed by the development of a diffuse papulosquamous rash. The herald patch often is misdiagnosed as eczema. Pityriasis rosea is difficult to identify until the appearance of characteristic smaller secondary lesions that follow Langer’s lines (cleavage lines). Several medications can cause a rash similar to pityriasis rosea, and several diseases, including secondary syphilis, are included in the differential diagnosis.

The clinical picture suggests a vitamin K deficiency haemorrhagic disease of the new-born and requires IV vitamin K and fresh frozen plasma. This usually presents with gastrointestinal bleeding, bleeding from the umbilical stump and bruising after 2–7 days.

Cytomegalovirus (CMV) is the most frequent cause of congenital infection worldwide, with an estimated incidence in developed countries of 0.6–0.7% of all live births.The clinical spectrum of congenital CMV infection varies widely, from the complete absence of signs of infection (asymptomatic infection) to potentially life-threatening disseminated disease. At birth, 85–90% of infected infants are asymptomatic, and 10–15% present with clinical apparent infection (symptomatic disease).The presentation in this latter group is a continuum of disease expression whose more common findings are petechiae, jaundice, hepatomegaly, splenomegaly, microcephaly, and other neurologic signs.

Based on the clinical scenario, the patient has features suggestive of acute otitis externa, which can be managed with topic antibiotics.Otitis externa:It can be classified as acute (< 3 weeks) or chronic (> 3 months). Frequent exposure to water, e.g. swimming, is a risk factor for the condition. Itching, pain, hearing loss and discharge are common complaints. Examination demonstrates oedema of the external auditory canal with discharge. Pain may be elicited on the movement of the tragus or pinna. First-line treatment is with topical drops/sprays for one week. Acidic preparations such as 2% acetic acid, antibiotic or combined antibiotic and corticosteroid preparations may be used (1% hydrocortisone and 0.3% gentamicin). Acetic acid can be used as the first-line treatment for mild cases without discharge or hearing impairment. On selecting an appropriate topical preparation remember that topical aminoglycosides are contraindicated if the tympanic membrane is perforated and that chloramphenicol ear drops cause contact dermatitis in approximately 10% of people. Clinoquinol, a combination of antibacterial and antifungal, may be preferred over aminoglycoside containing preparations due to the theoretical lower risk of ototoxicity and dermatitis. However, there is no clear evidence to support the use of one topical preparation over another.Other options:- Admit for IV antibiotics: First line management is with analgesia and topical antibiotic or combined antibiotic and corticosteroid preparations. Thus, IV antibiotics is not an appropriate action.- Oral antibiotics: Oral antibiotics like flucloxacillin or erythromycin are considered only for severe infections such as the spread of cellulitis beyond the ear canal. – Reassurance is not sufficient to treat these patients. They require topic antibiotic therapy.- Referral to ENT: Should be considered only in case of treatment failure. ENT referral can also be considered if there is cellulitis extending past the margin of the external ear canal, extreme pain or extensive swelling and discharge likely to require suction or the insertion of an ear wick. Urgent ENT referral is reserved for suspected cases of malignant otitis externa (with the extension of the condition into the adjacent bone and spreading osteomyelitis).

Zona fasciculata of the adrenal produces the maximum levels of cortisol in the body.Functions of cortisol:- Increases blood pressure: permits normal response to angiotensin II and catecholamines by up-regulating alpha-1 receptors on arterioles.- Inhibits bone formation: decreases osteoblasts, type 1 collagen and absorption of calcium from the gut, and increases osteoclastic activity.- Increases insulin resistance.- Increases gluconeogenesis, lipolysis and proteolysis.- Inhibits inflammatory and immune responses.- Maintains function of skeletal and cardiac muscle.An excess of corticosteroids in the body causes various symptoms that are a part of Cushing’s syndrome.

The most appropriate procedure in the surgical management of this child would be to perform an appendicostomy for anterior continence enemas (Malone procedure).Idiopathic constipation leading to faecal incontinence is managed in a stepwise progression, first with laxatives such as movicol, enemas and stronger laxatives and in younger children inter-sphincteric injection of botox may be performed. Following this either anal irrigation or antegrade continence enemas are performed. Appendicostomy for anterior continence enemas allow colonic washouts and thereby rapid achievement of continence.Other options:- Defunctioning Ileostomy: Although an option in extreme cases, an ACE stoma would be more appropriate in this child.- Laparotomy for resection of the megarectum is performed if ACE stoma fails due to megarectum.- Left hemicolectomy is a procedure reserved for slow-transit colons to increase transit time.- Bishop-Koop stoma: It is a procedure of historical significance. It is a way of washing out and managing meconium ileus.

The differentiation between type 1 and type 2 epithelia in the developing lung buds is evident from 16-24 weeks of gestation.Development of the respiratory tract has five stages:- Embryonic (at 4 – 5 weeks of gestation):Formation of lung buds, trachea and mainstem bronchi occur. These structures are formed from a ventral outpouching of foregut pharynx. At this stage, the beginnings of the five lung lobes are present.- Pseudoglandular (at 5 – 16 weeks of gestation):Formation of terminal bronchioles, cartilage and smooth muscles occur in this stage. – Canalicular (at 16-24 weeks gestation): Differentiation of type I and II epithelial cells can be done in this stage. There is also an increase in the size of proximal airways).- Saccular (at 24 – 40 weeks of gestation): Terminal saccule formation occurs. Production of surfactant takes place at this stage with an increase in the number of goblet cellsUp to half the adult number of alveoli are in place by this stage.- Alveolar (occurs between 32 weeks of gestation till the post-natal age 8): Formation of alveoli and septation occurs with the expansion of air spaces.

Liddle’s syndrome,  is an autosomal dominant disorder, that is characterized by early, and frequently severe, high blood pressure associated with low plasma renin activity, metabolic alkalosis, low blood potassium, and normal to low levels of aldosterone. Liddle syndrome involves abnormal kidney function, with excess reabsorption of sodium and loss of potassium from the renal tubule. Bartter Syndrome also presents with hypokalaemia, however blood pressure of these patients is usually low or normal.

Bulimia nervosa is an eating disorder that involves frequent episodes of binge eating followed by inappropriate purging behaviour. The underlying reason for this behaviour is distorted self-image. Bulimia leads to several medical issues, including various laboratory derangements. Among these deranged laboratory parameters are the hormone cholecystokinin, which is found to be decreased in women having bulimia. It is hypothesized that the bingeing episodes observed in patients with bulimia are due to lower levels of CCK since normal levels of CCK are involved in maintaining satiety and controlling the urge to binge eat.

The level of statistical significance is often expressed as a p-value between 0 and 1. The smaller the p-value, the stronger the evidence that you should reject the null hypothesis.A p-value less than 0.05 (typically ≤ 0.05) is statistically significant. It indicates strong evidence against the null hypothesis, as there is less than a 5% probability the null is correct (and the results are random). Therefore, we reject the null hypothesis, and accept the alternative hypothesis.However, this does not mean that there is a 95% probability that the research hypothesis is true. The p-value is conditional upon the null hypothesis being true is unrelated to the truth or falsity of the research hypothesis.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.

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.