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.

The history is suggestive of mumps. Mumps is a viral disease with initial signs and symptoms including fever, muscle pain, headache, poor appetite, and feeling tired. This is then usually followed by painful swelling of one or both parotid salivary glands. Mumps is a self-limiting condition treated only for symptomatic relief. As he currently is taking analgesics for pain relief, one should only offer reassurance.

The second pharyngeal arch or hyoid arch, is the second of six pharyngeal arches that develops in fetal life during the fourth week of development and assists in forming the side and front of the neck. Derivatives:
Skeletal – From the cartilage of the second arch arises:
Stapes,
Temporal styloid process,
Stylohyoid ligament, and
Lesser cornu of the hyoid bone.
Muscles:
Muscles of face
Occipitofrontalis muscle
Platysma
Stylohyoid muscle
Posterior belly of Digastric
Stapedius muscle
Auricular muscles
Nerve supply: Facial nerve

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.

Perforated appendices are common in children as it is more difficult to surgically assess an unwell child due to poor localisation of abdominal pain, and their inability to express discomfort. They are therefore prone to a greater risk of post operative complications including would infections, intra abdominal fluid collections, and chest infections. In the above scenario the spiking temperature points to an abscess, which characteristically presents with a swinging temperature. The fever is unlikely due to bacterial resistance as blood tests performed post surgery would have indicated any resistance, and a UTI is also unlikely since the child is already on antibiotics. As his chest is clinically clear, a severe chest infection may be ruled out, leaving intra-abdominal collection as the most likely explanation.

Haematuria and abdominal swelling may indicate either polycystic kidney disease or a tumour. Because of the patient’s age, the likelihood of a tumorous growth is small, thus an ultrasound is the best choice for this case.

Foreign body aspiration (FBA) commonly occurs in children aged 1–3 years. FBA typically presents with sudden onset of coughing and choking, followed by stridor and dyspnoea. Obstruction of the larynx or trachea is a potentially life-threatening situation that causes severe respiratory distress, cyanosis, and suffocation. Most commonly, the foreign body (FB) becomes lodged in the main and intermediate bronchi| approx. 60% of FB are located in the right main bronchus due to the more vertical orientation compared to the left main bronchus. Reduced breath sounds on the one side only would not be explained by a tracheal obstruction as it would cause reduced breath sounds bilaterally and a more severe clinical picture.

This is probably a case of protein-induced allergic proctitis, due to dietary protein transmitted through the mother to the breast-fed child. The mother should go on a milk-free and soya-free diet but continue to breast-feed.

The main problem with infants having gastroenteritis is dehydration. So they should be admitted to the hospital for IV fluids if they are not tolerating oral fluids.

In pyloric stenosis a new-born baby presents with a history of vomiting, constipation and deranged electrolytes. Excessive vomiting leads to hypokalaemia. Difficulty in food passing from the stomach to the small intestine causes constipation. Hypokalaemia also causes constipation. None of the other disorders mentioned present with the hypokalaemia, vomiting and constipation triad in a new-born.

The most common manifestation of Wilms tumour is an asymptomatic abdominal mass| an abdominal mass occurs in 80% of children at presentation. Abdominal pain or haematuria occurs in 25%. Urinary tract infection and varicocele are less common findings than these. Hypertension, gross haematuria, and fever are observed in 5-30% of patients. A few patients with haemorrhage into their tumour may present with hypotension, anaemia, and fever. Rarely, patients with advanced disease may present with respiratory symptoms related to lung metastases.

Although initially thought to affect only boys, girls with DMD also have an estimated 10% chance of inheriting the condition. In girls, DMD may present with all or some clinical manifestations.

The patient shows features of neurofibromatosis. The most likely cause for hypertension in this patient would be renal artery stenosis.Note:Neurofibromatosis is an inherited autosomal dominant disorder which could have affected this girl’s father, and she appears to have the classic skin lesions. A renal bruit might be heard in these patients. Polycystic kidney disease can occur in association with tuberous sclerosis, which also has skin lesions associated (different from those described in this patient). Most causes of hypertension in childhood have underlying renal causes, and a renal ultrasound with doppler is the first-line investigation of choice. Even if this is normal, further imaging would be indicated here, for example, isotope renal scans and angiography.

Ventilatory rates of 40-60 breaths/min should be provided initially, with proportionally fewer assisted breaths provided if the infant’s spontaneous respiratory efforts increase. Although this practice has not been extensively studied, initial inflation of the new-born’s lungs with either slow-rise or square-wave inflation to a pressure of 30-40 cm H2 O for approximately 5 seconds has been reported to result in more rapid formation of Functional Residual Capacity (FRC).At the moment of delivery and first breath, the neonatal lung is converting from a fetal non-aerated status to a neonatal status. The neonatal lung requires gas exchange, and this necessitates the development of FRC with the resorption of lung fluid and the resolution of most of the atelectasis. Therefore, initial slow ventilation with more prolonged inspiratory times may be useful to assist in this task, balanced against the need to avoid inappropriate inspiratory pressures.Flow-controlled, pressure-limited mechanical devices are acceptable for delivering PPV. These mechanical devices control flow and limit pressure and be more consistent than bags. Self-inflating and flow-inflating bags remain a standard of care. Laryngeal mask airways are effective for assisted ventilation when bag-mask ventilation and intubation are unsuccessful.

Based on the presentation, the developmental age of the child is 8 months.The primitive reflexes are indicators of functional integrity and maturity. The majority of reflexes do not persist beyond 6 months of age. There are 13 reflexes of importance, including:- Moro reflex- Startle reflex- Rooting reflex- Sucking reflex- Grasp reflex- Voluntary palmar grasp reflex- Voluntary reach reflex- Stepping reflex- Asymmetrical tonic neck reflex (ATNR)- Parachute reflex- Plantar reflex- Tendon reflex- ClonusIt is interesting to note that gastrocolic reflex is not a primitive reflex.Ninety-five per cent of reflexes will have disappeared by the ages shown below:- 6 weeks: Stepping- 3-4 months: Palmar grasp and Moro- 6 months: Sucking, rooting, and asymmetrical tonic neck reflex (ATNR)

A monochorionic diamniotic (MCDA) twin pregnancy is a subtype of monozygotic twin pregnancy. An MCDA pregnancy results from a separation of a single zygote at ,4-8 days (blastocyst) following formation. These fetuses share a single chorionic sac but have two amniotic sacs and two yolk sacs. It accounts for the vast majority (70-75%) of monozygotic twin pregnancies although only ,30% of all twin pregnancies. The estimated incidence is at ,1:400 pregnanciesThe layman term is that the twins are identical – in reality, they are phenotypically similar, and of course of the same gender.

The most probable cause for the patient’s symptoms would be pes anserine bursitis.Translated, pes anserinus means goose feet. It is the term used to describe the unified bursa enclosing the tendons of the sartorius, gracilis and semitendinous muscles inserting into the anteromedial proximal tibia.Pes anserine bursitis is common in people doing sports due to overuse injuries. The main sign is of pain in the medial part of the proximal tibia. As the McMurray test is negative, medial meniscal injury is excluded.

Breast feeding should be continued for babies with breast milk jaundice as this is a benign condition.

The boy has an increased BMI which implies he is overweight. Possible trauma to his pancreas might have led to a diabetes-like condition, induced by damage to the beta cells. Fasting blood glucose should be measured as a follow-up strategy to see if the damage is reversible or irreversible and to conclude if the glycosuria is related to his metabolic profile or to his accident.

Syphilis is an infectious venereal disease caused by the spirochete Treponema pallidum. Syphilis is transmissible by sexual contact with infectious lesions, from mother to foetus in utero, via blood product transfusion, and occasionally through breaks in the skin that come into contact with infectious lesions. If untreated, it progresses through 4 stages: primary, secondary, latent, and tertiary.

Gitelman syndrome is a kidney disorder that causes an imbalance of charged atoms (ions) in the body, including ions of potassium, magnesium, and calcium.The signs and symptoms of Gitelman syndrome usually appear in late childhood or adolescence. Common features of this condition include painful muscle spasms (tetany), muscle weakness or cramping, dizziness, and salt craving. Also common is a tingling or prickly sensation in the skin (paraesthesia), most often affecting the face. Some individuals with Gitelman syndrome experience excessive tiredness (fatigue), low blood pressure, and a painful joint condition called chondrocalcinosis. Studies suggest that Gitelman syndrome may also increase the risk of a potentially dangerous abnormal heart rhythm called ventricular arrhythmia.

Fragile X syndrome is a genetic syndrome associated with neuro-developmental problems such as learning disabilities and cognitive impairment, with many affected children having mild to moderate intellectual disability. About a third of children have features of autism spectrum disorder and ADHD which affects their communication skills and social interactions. As such, affected individuals usually have delayed speech development and poor nonverbal skills such as gaze aversion. Symptoms tend to worsen with age into adolescence as the demands on their intellect becomes greater. Pre-mutation carriers, who posses smaller genetic repeat expansions, have been found to be associated with some neurodevelopment and other medical problems.

The most appropriate diagnosis for this patient is appendicular mass. The initial treatment, according to the Ochsner-Sherren regimen recommended by Hamilton Bailey, would be the initiation of intravenous antibiotics.RationaleThe presentation is highly suggestive of appendicular mass. The correct management is broad-spectrum intravenous antibiotics such as co-amoxiclav and amikacin plus observation. Conservative management is the preferred treatment as surgical exploration at this stage can result in increased morbidity.The child should be allowed to eat and drink. If there are on-going temperature spikes, signs of obstruction or severe colicky abdominal pain, then surgery is required. The majority of patients respond to conservative management.Other options:- This is a partially treated appendicitis which has formed an appendix mass. Rather than planning appendectomy immediately| Hamilton Bailey recommended interval appendectomy after 6 weeks post-discharge. However, the need for interval appendectomy is still under debate.- Drainage via interventional radiology is not recommended in this patient as it can lead to swinging pyrexia secondary to peritonitis secondary to the collection.- The patient would have high-grade pyrexia and be constitutionally unwell if the patient was a patient of pyelonephritis. The presentation of the patient is more suggestive of appendicular mass.- The history would be more extended with symptoms of weight loss and altered bowel habit if the patient had Crohn’s disease.

Familial adenomatous polyposis can have different inheritance patterns.When familial adenomatous polyposis results from mutations in the APC gene, it is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In most cases, an affected person has one parent with the condition.When familial adenomatous polyposis results from mutations in the MUTYH gene, it is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. Most often, the parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but do not show signs and symptoms of the condition.

Peutz-Jeghers syndrome (PJS) is an autosomal dominant inherited disorder characterized by intestinal hamartomatous polyps in association with a distinct pattern of skin and mucosal macular melanin deposition (freckles on the lips, face, palms and soles). Patients with Peutz-Jeghers syndrome have an estimated 15-fold increased risk of developing intestinal cancer compared to the general population.Management: conservative unless complications develop.

Germinal matrix/intraventricular haemorrhage (GM/IVH) is a complication of premature delivery that can result in life-long medical and developmental consequences. Although GM/IVH can occur in term infants, haemorrhage in this group of infants remains distinct from periventricular haemorrhage (PVH)/IVH of the preterm infant. Several acquired lesions of the central nervous system (CNS) specifically affect infants born prematurely and result in long-term disability, including GM/IVH, periventricular white matter injury (e.g., cystic periventricular leukomalacia [CPVL], periventricular haemorrhagic infarction [PVHI]), haemorrhage, and diffuse injury to the developing brain.The physical examination is usually negative in germinal matrix/intraventricular haemorrhage (GM/IVH). Occasionally, severe GM/IVH may present with nonspecific systemic findings suggestive of cardiovascular collapse.One subgroup of infants with GM/IVH presents with the following:- A sudden unexplained drop in haematocrit levels- Possible physical findings related to anaemia (e.g., pallor, poor perfusion) or haemorrhagic shockAnother subgroup of infants with GM/IVH presents with extreme signs, including the following:- A sudden and significant clinical deterioration associated with anaemia, metabolic acidosis, glucose instability, respiratory acidosis, apnoea, hypotonia, and stupor is present.Physical findings related to these signs include poor perfusion, pallor or an ashen colour, irregularities of respiratory pattern, signs of respiratory distress including retractions and tachypnoea, hypotonia, and altered mental status (e.g., decreased responsiveness, coma).Additional neurologic signs, such as fullness of the fontanelles, seizures, and posturing, may also be observed. Progression can be rapid and may result in shock and death.Extradural haemorrhage also known as an epidural hematoma, is a collection of blood that forms between the inner surface of the skull and outer layer of the dura, which is called the endosteal layer. They are usually associated with a history of head trauma and frequently associated skull fracture. The source of bleeding is usually arterial, most commonly from a torn middle meningeal artery.A subdural haemorrhage (or hematoma) is a type of bleeding that often occurs outside the brain as a result of a severe head injury. It takes place when blood vessels burst between the brain and the leather-like membrane that wraps around the brain (the dura mater). The pooling blood creates pressure on the surface of the brain, causing a variety of problems.

The presentation of the child is highly suggestive of Henoch-Schonlein 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 – 6 years old 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 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.

The most probable diagnosis in this patient would be pulmonary stenosis. Pulmonary Stenosis:Pulmonary valve murmurs are heard in the upper left sternal edge, associated with a thrill but no desaturation in the absence of an additional shunt. The ECG changes suggest right ventricular hypertrophy. Pulmonary stenosis is often well tolerated in childhood unless severe. These should be monitored with serial echocardiography, and balloon pulmonary valvoplasty should be considered once the pressure gradient reaches 64 mmHg.Other options:- Atrial septal defect: While atrial septal defects are associated with right ventricular outflow tract murmurs, they would not cause a thrill.- Patent ductus arteriosus: PDA murmurs can be audible in the left upper sternal edge, but would normally be audible in the left infraclavicular area and be continuous rather than ejection systolic. This left to right shunt would not cause desaturation but does cause left-sided volume loading and hence left-sided ECG changes.- Tetralogy of Fallot: Ventricular septal defect, overriding aorta, subpulmonary stenosis, and right ventricular hypertrophy. This would often cause a ULSE murmur with a thrill and RVH on ECG. However, this degree of obstruction would cause shunting from right to left, and this child would be desaturated.- Ventricular septal defect: Isolated ventricular septal defects cause pansystolic murmurs at the left lower sternal edge. They would have left-sided ECG changes and normal saturations (in the absence of pulmonary hypertension).

Usually, a total serum bilirubin level test is the only one required in an infant with moderate jaundice who presents on the second or third day of life without a history and physical findings suggestive of a pathologic process. Measurement of bilirubin fractions (conjugated vs unconjugated) in serum is not usually required in infants who present as described above. However, in infants who have hepatosplenomegaly, petechiae, thrombocytopenia, or other findings suggestive of hepatobiliary disease, metabolic disorder, or congenital infection, early measurement of bilirubin fractions is suggested. The same may apply to infants who remain jaundiced beyond the first 7-10 days of life, and to infants whose total serum bilirubin levels repeatedly rebound following treatment.

Treating persons infected with C. trachomatis prevents adverse reproductive health complications and continued sexual transmission, and treating their sex partners can prevent reinfection and infection of other partners. Treating pregnant women usually prevents transmission of C. trachomatis to neonates during birth. Chlamydia treatment should be provided promptly for all persons testing positive for infection. Treatment delays have been associated with complications (e.g. PID) in a limited proportion of women. To minimise disease transmission to sex partners, persons treated for chlamydia should be instructed to abstain from sexual intercourse for 7 days after single-dose therapy or until completion of a 7-day regimen and resolution of symptoms if present. To minimise risk for reinfection, patients also should be instructed to abstain from sexual intercourse until all of their sex partners are treated. Persons who receive a diagnosis of chlamydia should be tested for HIV, GC, and syphilis.