The most possible diagnosis is SVT. The boy is suffering from hemodynamic instability, as indicated by his cold extremities. DC cardioversion is the treatment of choice.

The thyroid gland is one of the first endocrine glands to develop, and is formed from the endoderm of the epithelial tissue of the primitive pharynx. The mature gland is functionally made up of follicles with colloid which contain the pro hormone thyroglobulin. Thyroid hormone is synthesised at a cellular level and is stored as thyroglobulin, before its release as thyroid hormone, a major modulator of metabolism. In between the follicular cells are parafollicular, or C-cells which secrete parathyroid hormone or calcitonin which are responsible for calcium regulation in the body.

A cohort study is a particular form of longitudinal study that samples a cohort (a group of people who share a defining characteristic, typically those who experienced a common event in a selected period, such as birth or graduation), performing a cross-section at intervals through time. The relative risk (RR) or risk ratio is the ratio of the probability of an outcome in an exposed group to the probability of an outcome in an unexposed group. Relative risk is used in the statistical analysis of the data of experimental, cohort and cross-sectional studies, to estimate the strength of the association between treatments or risk factors, and outcomes.

Amoxicillin has high efficacy against haemophilus influenza and streptococcus pneumonia, the most common organisms of otitis media. It is an oral drug with high bioavailability.

Advancing paternal age has been linked with lower quality sperm leading to a reduction in overall fertility and an increase in the occurrence of various medical disorders in the fetus. Advanced paternal age has been implicated as a risk factor for diseases like retinoblastoma, achondroplasia, autism spectrum disorders, schizophrenia, and acute lymphoblastic leukaemia. Down’s syndrome is mostly considered a consequence of advanced maternal age, but advanced paternal age has also been implicated as a risk factor.

Treatment of depression is an important component of maternal and neonatal health. The use of SSRIs and antidepressants in the first trimester are unlikely to carry any congenital risks. However the use of the antidepressants closer to delivery may result in some respiratory, motor, gastrointestinal and central nervous system problems, with the most concerning of these being persistent pulmonary hypertension of the new-born. Other conditions such as cleft palate, jaundice, neural tube defects or floppy baby syndrome have not been shown to occur with SSRI use.

The boy is most probably a type 1 diabetic patient. Such a condition can affect the behaviour and psychological state of a young child reflected in their behaviour. The parents should seek the help of a clinical psychologist.

Tinea corporis is a type of dermatophytosis, caused by Trichophyton or Microsporum. The disease is highly contagious and rapidly spreads to all the areas of the body, including the glabrous skin. It produces an erythematous itchy skin rash with a central area of clearance surrounded by raised scaly borders. Lesions can appear as concentric circles that overlap, referred to as tinea imbricate.

Henoch-Schonlein purpura (HSP), also known as IgA vasculitis, is a disease of the skin, mucous membranes, and sometimes other organs that most commonly affects children. In the skin, the disease causes palpable purpura (small, raised areas of bleeding underneath the skin), often with joint pain and abdominal pain. It is an acute immunoglobulin A (IgA)-mediated disorder. The tetrad of purpura, arthritis, kidney inflammation, and abdominal pain is often observed.

Duchenne muscular dystrophy has an X-linked recessive pattern of inheritance. Since the first son is affected by the disease, it means that the mother is a carrier. The male children will inherit the Y chromosome from their father and the X chromosome from their mother, having 50% chances of inheriting the X chromosome with the affected gene.

Port-wine stains are a type of vascular birthmark caused by the abnormal development of capillaries in the skin. These pinkish-purplish discolorations present at birth and are associated with medical conditions such as Sturge-Weber syndrome, a neurocutaneous disorder involving the leptomeninges. Port wine stains are therefore associated with epilepsy, glaucoma or intellectual disability common in Sturge-Weber syndrome. Additional complications of Port wine stains include a loss of function if near the eye or mouth due to hypertrophy, or glaucoma if near the eyelid.

The central nervous system comprises of two types of cells; neurons and neuroglial cells. Glial cells are the support cells that serve a number of important functions. Three types of neuroglia comprise the mature nervous system, which are ependymal cells, microglia, and macroglia. The macroglia are of two types oligodendrocytes and astrocytes. Microglia are the neuroglial cells that serve the function of phagocytosis since they are derived from the hematopoietic stem cells and share properties with tissue macrophages. They remove the cellular debris from the site of injury or normal cellular turnover by performing scavenger function.

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.

The most probable diagnosis for this patient would be Coarctation of Aorta (CoA).Infants with CoA present within the first few weeks of life with signs suggestive of congestive cardiac failure and general circulatory shock. In these patients, the aorta is supplied by the right ventricle, via the ductus arteriosus. Pathophysiology:When the left ventricle supplies the aorta via the aortic isthmus, children are usually asymptomatic or may present with occasional complaints of leg pain. Associated cardiac anomalies are uncommon but for a bicuspid aortic valve, which is present in approximately 50% of cases. Good collateral circulation usually develops in these patients, which in the long term, causes notching of ribs. Clinical Presentation:Clinically, there may be hypertension in the upper limbs (or higher BP readings than in the lower limbs), and leg pulses are absent, or weak and delayed. A systolic click and aortic ejection systolic murmur are heard, caused by the bicuspid aortic valve. Management:The primary medical management is to treat hypertension. After stabilization, the patient can undergo definitive surgical repair. Transcatheter balloon angioplasty of the coarctation is controversial, but ballooning +/- stenting of re-coarctation following surgery is commonly performed.Systemic hypertension may occur following repair, even in the absence of re-coarctation necessitating the re-initiation/continuation of antihypertensive therapy in these patients.

Recurrent bacterial infections may be due to lack of B-cell function, consequently resulting in a lack of gamma globulins production. Once the maternal antibodies have depleted, the disease manifests with greater severity and is called x-linked agammaglobulinemia also known as ‘X-linked hypogammaglobulinemia’, ‘XLA’ or ‘Bruton-type agammaglobulinemia. it is a rare x linked genetic disorder that compromises the bodies ability to fight infections. Acute leukaemia causes immunodeficiency but not so specific. DiGeorge syndrome is due to lack of T cell function. Aplastic anaemia and EBV infection does not cause immunodeficiency.

McCune-Albright syndrome, characterised by polyostotic fibrous dysplasia, cafe au lait spots, sexual precocity, and hyperfunction of multiple endocrine glands, is the result of G-protein abnormality.

Nissl body is a neuron-specific cellular structure. It is composed of rough endoplasmic reticulum and fine granules. The rough endoplasmic reticulum contains free ribosomes, and are the hub of protein synthesis. When these substances are exposed to a cresyl violet solution, they show selective-staining by turning purple-blue. In pathologic processes, they may undergo chromatolysis.

The most probable diagnosis for this patient’s symptoms is psoriasis. Psoriasis:Chronic plaque psoriasis is characterised by pinkish-red hyperkeratotic plaques, which occur mainly on extensor surfaces such as knees and elbows. The lower back, ears and scalp can also be involved. Koebner phenomenon: Psoriasis typically exhibits this phenomenon where new plaques of psoriasis occur particularly at sites of skin trauma. Diagnosis:Skin biopsy of psoriatic plaques reveals acanthosis and parakeratosis, reflecting increased skin turnover. Capillary dilatation within the dermis also occurs, surrounded by a mixed neutrophilic and lymphohistiocytic perivascular infiltrate.

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.

Presentation can vary by individual. Early stages are often characterized by malaise, fatigue, and lethargy. One to 3 months of inadequate intake can lead to anaemia, myalgia, bone pain, easy bruising (Figure 3), swelling, petechiae, perifollicular haemorrhages, corkscrew hairs, gum disease, poor wound healing, mood changes, and depression. Perifollicular haemorrhages and easy bruising are often first seen in the lower extremities, as capillary fragility leads to an inability to withstand hydrostatic pressure. Late stages of scurvy are more severe and life threatening; common manifestations include generalized oedema, severe jaundice, haemolysis, acute spontaneous bleeding, neuropathy, fever, convulsions, and death.

This clinical case is most probably due to intussusception complicated by sepsis. Regardless of the cause, the baby is sick and in a critical condition. The first thing to do is to preserve the vital signs and resuscitate with IV fluids. As sepsis is suspected, you should also start on triple antibiotics.

Relative risk = (Incidence in exposed group)/incidence in unexposed group). So in this case RR = (50/100)/(50/200) = 2.

The most probable diagnosis for this patient is Maple syrup urine disease (MSUD).Note:- Healthy new-borns have blood sugars between 3.3 and 5 mmol/L- Neonatal hypoglycaemia is glucose < 2.2 mmol/L if measured in the first 3 days of life.- Neonatal hypoglycaemia is glucose < 2.5 mmol/L after the first 3 days of life.Causes of persistent hypoglycaemia include:- Preterm- IUGR- SGA- Hyperinsulinism due to maternal diabetes- Beckwith-Wiedemann syndrome- Hypoxia at birth- Sepsis- Cardiopulmonary disease- Inborn errors of metabolism- Hepatic enzyme deficiencies- Glycogen storage disease

The most appropriate action in this baby would be to perform HIV PCR and commence cART and PCP prophylaxis if HIV positive.Treatment guidelines for HIV-positive infants state that all should receive combination antiretroviral therapy (cART) and Pneumocystis jiroveci pneumonia (PJP) prophylaxis, irrespective of CD4 count or viral load.

The IM dose of adrenaline for anaphylaxis in:< 6 months: 150 micrograms (0.15ml 1 in 1,000)6 months – 6 years: 150 micrograms (0.15ml 1 in 1,000)6 – 12 years: 300 micrograms (0.3ml 1 in 1,000)Adult and child > 12 years: 500 micrograms (0.5ml 1 in 1,000)Anaphylaxis:Anaphylaxis is an acute, rapidly progressing, potentially life-threatening IgE mediated Type I hypersensitivity reaction.It involves the release of mediators from mast cells, basophils and inflammatory cells. It is characterised by oedematous swelling of the airway mucosa giving rise to dyspnoea and respiratory distress. The most common cause of anaphylaxis in children is a food allergy.Risk factors for death in patients with anaphylaxis include asthma, age 11+, peanut allergy, and delay in adrenaline administration.Management of anaphylaxis includes:- ABCD- Remove the allergen- IM adrenaline or Nebulised adrenaline- IV Hydrocortisone – pro re nata IV fluid support. – Followed by observation.

Intussusception causes abdominal pain leading to painful lower GI bleeding. Intussusception is a condition in which part of the intestine folds into the section next to it. It most commonly involves the small bowel and rarely the large bowel. Intussusception doesn’t usually require surgical correction. 80% of cases can be both confirmed and reduced using barium, water-soluble or air-contrast enema.However, up to 10% of cases can experience recurrence within 24 hours after reduction, warranting close monitoring during this period.Most children have self-limiting and minor bleeds. However, children with massive bleeds will need emergency care and stabilisation.The various causes of lower GI bleeding in neonates include:- Anal fissures- Milk protein or soy allergy- Intussusception- Volvulus- Coagulopathies including haemorrhagic disease of the new-born- Arteriovenous malformations- Necrotising enterocolitis- Hirschsprung enterocolitis- Meckel’s diverticulitis- Drugs (NSAIDs, heparin, indomethacin used for patent duct closure, dexamethasone)The various causes of lower GI bleeding in children aged between 1 month to 2 years include:- Infection- Anal fissures- Intussusception- Malrotation with volvulus- Milk protein or soy allergy- Polyp- Meckel’s diverticulum- Duplication cyst- Foreign body- AV malformation- Colitis of immune deficiency- Tumour- HaematomaThe causes of lower GI bleeding in children older than 2 years include:- Polyp- Inflammatory bowel disease (IBD)- Infectious diarrhoea (caused by Escherichia coli and Shigella)- Intussusception- Haemangiomas- Arteriovenous malformations- Vasculitis- Tumour

NICE does not recommend the use of antibiotics or tonsillectomy in this case. Paracetamol/Ibuprofen are indicated as they provide antipyretic action and analgesia. Indications for tonsillectomy are 5 or more episodes of acute sore throat/year, symptoms present for at least 2 years, symptoms are severe enough to disrupt a child’s social life. Indications for antibiotics are features of marked systemic upset secondary to the acute sore throat, unilateral peritonsillitis, history of rheumatic fever, an increased risk from acute infection, acute tonsillitis with 3 or more of the following: history of fever, tonsillar exudates, no cough and tender anterior cervical lymphadenopathy.

Cleansing and debridement is paramount in dealing with tetanus-prone wounds (severe crushing injuries, piercing wounds, blisters and burns are outstanding examples, particularly if contaminated with dirt, grass or other debris).Prophylaxis then is relatively easy in persons who have been actively immunized by toxoid injections. For them, a boosterť injection is indicated. There is experimental evidence that antibiotics of the tetracycline group, given soon after injury, may have prophylactic effect against tetanus.

The diagnosis of scabies can often be made clinically in patients with a pruritic rash and characteristic linear burrows. Definitive testing relies on the identification of mites or their eggs, eggshell fragments, or scybala. This is best undertaken by placing a drop of mineral oil directly over the burrow on the skin and then superficially scraping longitudinally and laterally across the skin with a scalpel blade. (Avoid causing bleeding.) Scraping 15 or more burrows often produces only 1 or 2 eggs or mites, except in a case of crusted scabies, in which many mites will be present. The sample is placed on a microscope slide and examined under low and high power. Potassium hydroxide should not be used, since it can dissolve mite pellets. Failure to find mites is common and does not rule out the diagnosis of scabies.

Orbital bone fracture: The child has sustained a head injury and subsequently describes a CSF rhinorrhoea (indicating a cerebro-spinal fluid leak). CSF rhinorrhoea can occur in skull or nasal bone fractures. Given the symptoms of loss of consciousness and headache, this child is more at risk of having suffered a skull fracture requiring emergency CT head investigation and specialist neurosurgical management. An ethmoid bone fracture may also present this way. A skull x ray would help to determine an air fluid level and indeed allow some visualisation of the nasal bones, though in children the nasal bones do not visualise well due to lack of fusion. Either way this child would need assessment in the nearest Emergency Department and the school would be expected to follow a ‘head injury’ protocol.