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.

Howell-Jolly bodies are often seen in post-splenectomy cases, together with Pappenheimer bodies, target cells and irregular contracted red blood cells. The loss of splenic tissue results in the inability to readily remove immature or abnormal red blood cells from the circulation.

A vasovagal episode or vasovagal syncope is the most common form of reflex syncope. Reflex syncope is a general term used to describe types of syncope resulting from a failure in autoregulation of blood pressure, and ultimately, in cerebral perfusion pressure resulting in transient loss of consciousness. The mechanisms responsible for this are complex and involve both depression of cardiac output as well as a decrease in vascular tone. Other types of reflex syncope include carotid sinus syncope and situational syncope, for instance, cough or micturition syncope. Vasovagal syncope may be triggered by pain or emotional upset, although frequently a specific trigger cannot be identified.

Scabies infection in neonates typically manifests as nodular eruptions involving the face, neck, scalp, palms, and soles in contrast to the predominant involvement of the hands, wrists, elbows, and ankles in adults. Differential diagnoses for the nodular eruption in neonates are broad, and scabies often is misdiagnosed as Langerhans cell histiocytosis, urticaria pigmentosa, or another pruritic, bullous, or lymphoproliferative dermatosis. Histopathology of the reactive nodules usually is not diagnostic, because scabetic organisms are often unidentified and histologic findings are nonspecific. Furthermore, because of the atypical presentation, scabies in children is often missed until persons in close contact with the child present with similar symptoms. Thus, a thorough history and close follow-up are crucial to avoid misdiagnosis and unnecessary aggressive treatment. Moreover, synchronized treatment of patients and their close contacts is needed to ensure the success of therapy, considering that relapse is 2-3 times more frequent in children and infants

The best answer is Polycystic Ovarian Syndrome (PCOS), supported by amenorrhea, obesity and acne. High insulin levels are indicative of PCOS and exclude Cushing syndrome (as this is associated with low insulin levels).

A teratoma is a tumour containing tissue elements that are similar to normal derivatives of more than one germ layer. They usually contain skin, hair, teeth and bone tissue and are more common in children, behaving as a benign tumour. After puberty, they are regarded as malignant and can metastasise.

The European Society of Human Reproduction and Embryology/American Society for Reproductive Medicine Rotterdam consensus (ESHRE/ASRM) developed and enlarged the diagnosis of PCOS, requiring two of three features: anovulation or oligo-ovulation, clinical and/or biochemical hyperandrogenism, and polycystic ovarian morphology (PCOM) seen on ultrasound. Finally the Androgen Excess Society defined PCOS as hyperandrogenism with ovarian dysfunction or polycystic ovaries

The paired sample t-test, sometimes called the dependent sample t-test, is a statistical procedure used to determine whether the mean difference between two sets of observations is zero. In a paired sample t-test, each subject or entity is measured twice, resulting in pairs of observations. Common applications of the paired sample t-test include case-control studies or repeated-measures designs.Statistical significance is determined by looking at the p-value. The p-value gives the probability of observing the test results under the null hypothesis. The lower the p-value, the lower the probability of obtaining a result like the one that was observed if the null hypothesis was true. Thus, a low p-value indicates decreased support for the null hypothesis. However, the possibility that the null hypothesis is true and that we simply obtained a very rare result can never be ruled out completely. The cut-off value for determining statistical significance is ultimately decided on by the researcher, but usually a value of .05 or less is chosen. This corresponds to a 5% (or less) chance of obtaining a result like the one that was observed if the null hypothesis was true.

Based on the presenting features, the patient has developed a septal haematoma after the trauma. Septal hematoma:In this condition, blood collects between the septal cartilage and the perichondrium. The patient classically presents with symptoms of nasal difficulty and pain following a nasal injury. Care should be taken not to misdiagnose a septal haematoma as a blood clot on the septum. In the case of a septal haematoma the swelling will typically be visible on both sides of the septum although this is not always the case. Referral to an ENT surgeon is indicated because, if untreated, there is a high risk of cartilage breakdown and complications related to infection.Other options:- The nosebleed has now stopped therefore compression is no longer required. The boy has developed a septal haematoma after traumatic injury. – CT head is not indicated in this patient as the diagnosis is clearly a septal hematoma.- Management of a septal hematoma consists of drainage and antibiotics. There is no role for intranasal corticosteroids.- If untreated, there is a high risk of cartilage breakdown and complications related to infection. Thus, referral to the ENT is essential| reassurance and discharge can lead to complications.

The physical features and developmental delay are the key aspects in the given scenario. The child in question shows features of gross motor and social developmental delay and has physical features indicative of Prader-Willi syndrome (hypopigmentation, esotropia, disproportionately small hands and feet, loss of central muscle tone and undescended testes). Children with Prader-Willi syndrome can present with failure to thrive until ,12-18 months, at which point, hyperphagia and obesity become more prominent. Other options:- Although Klinefelter syndrome can present with delayed development, undescended/small testes and reduced muscle power, the presence of small hands/feet, hypopigmentation and failure to thrive are not characteristic features. – Marfan syndrome presents with different physical features (arachnodactyly, cardio-respiratory complications and skin changes, amongst others) than those associated with Prader-Willi syndrome. – DiGeorge can manifest with developmental delay, hypotonia and feeding difficulties. However, this clinical scenario does not report any of the typical facial features, hearing abnormalities or cardiac abnormalities that are typically caused by DiGeorge syndrome. – Russell-Silver syndrome can cause developmental abnormalities, poor muscle tone and power (poor head control and muscle function), feeding difficulties and poor growth during the post-natal period and infancy. However, characteristic facial (small, triangular face, blue sclerae) and skeletal abnormalities (limb asymmetry, finger abnormalities) are not present. Therefore, Prader-Willi syndrome is the most appropriate diagnosis for this patient.Note:Prader-Willi syndrome is an example of genetic imprinting where the phenotype depends on whether the deletion occurs on a gene inherited from the mother or father: In Prader-Willi syndrome, it is the paternal gene that is deleted from the long arm of chromosome 15, while in Angelman syndrome the maternal gene is deleted. Prader-Willi syndrome can occur due to the microdeletion of paternal 15q11-13 (70% of cases) maternal uniparental disomy of chromosome 15.

Among the options provided, zidovudine causes lipoatrophy as a side effect.Zidovudine: Although both hypertrophy and atrophy are described related to HIV medications, nucleoside reverse transcriptase inhibitor (NRTIs) such as zidovudine and stavudine are closely associated with fat loss.Other options:- Enfuvirtide is an HIV-fusion inhibitor. Lipoatrophy is not commonly associated with this drug.- Efavirenz is an NNRTI, which is not associated with lipoatrophy. Common side effects include neuropsychiatric effects, rash and nausea. – Ganciclovir is not an anti-HIV medication and is used for cytomegalovirus (CMV) infections.- Raltegravir is an integrase inhibitor and is associated with fat gain.

Children who present with ruptured appendices are at increased risk of intra abdominal collections or abscesses. A swinging temperature is the first clue in indicating an intra abdominal abscess in a patient who had recently undergone surgery for a perforated appendix. The best course of action is therefore to get an ultrasound of the fluid collection before proceeding to rule out any other complication.

Turners syndrome is a chromosomal syndrome affecting the development of females. In this condition, all or part of the X chromosome gets deleted, producing the Karyotype 45 XO or 45XO/46XX. Spontaneous foetal loss is common in the first trimester, but foetuses which survive are born small for date, and may have lymphedema, and poor feeding in the neonatal period. These patients face numerous medical and developmental problems throughout their lifetimes including growth and puberty failure due to premature ovarian failure/ hypergonadotropic hypogonadism. However spontaneous puberty can be seen in up to 20% of females with Turner’s syndrome.

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 study described in the question is a ‘cohort’ study.Other options:A prospective observational study – When groups are classified according to one or more factors at a given time and followed forward to determine outcomes (usually some health status)- Although there is in one sense a control group (those who do not develop the health problem), this is not generally called a ‘controlled’ trial. – An ecological study would look at outcomes in different groups (countries or regions usually) who follow different practices.

Due to its cholestatic properties, Flucloxacillin can block bile flow through the liver, leading to the accumulation of bilirubin in the blood, giving rise to jaundice. Dark urine is the result of excessive bilirubin in the blood being filtered by the kidney. As the bile doesn’t move into the small intestine, stools are pale.

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).

Hypopigmentation refers to a decrease in the amount of the pigment melanin in the skin, which leads to an abnormally lighter skin tone. Hypopigmentation can be generalized or localized. Generalized hypopigmentation occurs in albinism or can be ethnicity related. Causes of localized hypopigmentation include Incontinentia pigmenti, Lichen planus, Tuberous sclerosis, Piebaldism, vitiligo, and leprosy. Celiac disease is not associated with hypopigmentation.

Kawasaki disease is an acute febrile illness of early childhood characterized by vasculitis of the medium-sized arteries. Diagnostic criteria include fever of at least 5 days duration along with 4 or 5 of the principal clinical features – extremity changes, polymorphous rash, oropharyngeal changes, conjunctival injection and unilateral nonpurulent cervical lymphadenopathy.

Power calculations are a important step in study design and preparation, but do not directly help with the interpretation of the results. They are used to determine how many subjects are needed in order to avoid errors in accepting or rejecting the null hypothesis. These calculations are not usually complex and for the best results, the power of the test should be set to above 80%.