Pyloric stenosis affects infants, typically in the second to fourth weeks of life and is caused most commonly by hypertrophy and thickening of the pylorus. It usually presents with projectile vomiting and failure to thrive. The infant usually has a normal appetite. Features include: ‘projectile’ vomiting, typically 30 minutes after a feed, constipation and dehydration may also be present and a palpable mass may be present in the upper abdomen.

Based on the clinical scenario provided, the most probable diagnosis for this patient would be tuberous sclerosis which is an autosomal dominant condition.Among the options provided, only Neurofibromatosis Type 1 is inherited by an autosomal dominant pattern. Other options:- Beckwith-Wiedemann syndrome is an example of an imprinting disorder and results from abnormalities of inheritance or methylation of chromosome 11p15.- Cystic fibrosis is an autosomal recessive condition.- Duchenne Muscular Dystrophy is an example of an X-linked recessive condition.- Hypophosphataemic (Vitamin D resistant) rickets is an X-linked dominant condition.

The mesonephric duct is one of the paired embryogenic tubules that drain the primitive kidney (mesonephros) to the cloaca. It also gives off a lateral branch forming the ureteric bud. In both the male and the female the Wolffian duct develops into the trigone of the urinary bladder. When the ducts are exposed to testosterone during embryogenesis, male sexual differentiation occurs: the mesonephric duct develops into the rete testis, the ejaculatory ducts, the epididymis, the ductus deferens and the seminal vesicles.

Henoch–Schönlein 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.

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.

The symptoms of excessive salivation and diarrhoea, along with hypotension, bradycardia, and bronchoconstriction, indicates excess parasympathetic nervous system activity. The patient is showing features of acetylcholine toxicity. Pesticides typically contain organophosphates that are potent inhibitors of acetylcholinesterase. This enzyme is responsible for the metabolism of acetylcholine. Acetylcholine is the neurotransmitter used in the neuromuscular junction, as well as at select points in the autonomic nervous system. The autonomic acetylcholine receptors can be nicotinic (more sensitive to nicotine) or muscarinic (more sensitive to muscarine). The most relevant receptors in this scenario are the muscarinic receptors as the majority are located in the parasympathetic nervous system smooth muscle, exocrine glands, and cardiac conduction system.Other options:- Accordingly, to cause the symptoms described, there must be an abundance of acetylcholine which stimulates the muscarinic receptors to enhance the parasympathetic effects. Therefore the reduction in the formation of acetylcholine option must be incorrect as this would produce the opposite effect. – Noradrenaline is the primary neurotransmitter in the sympathetic nervous system, and both answer options relating to noradrenaline would increase the neurotransmitter and potentiate the sympathetic nervous system effects, making them incorrect.Features can predict the accumulation of acetylcholine (mnemonic = SLUD):- Salivation- Lacrimation- Urination- Defecation/diarrhoeaCardiovascular symptoms include hypotension and bradycardia. The patient can show associated small pupils and muscle fasciculationManagement:- Atropine- The role of pralidoxime is still unclear – meta-analyses to date have failed to show any clear benefit.

Bone age is used to determine the maturation of a child’s bones’ and is used to detect pathological growth. This is done using the X-ray of the wrist. Several conditions can either advance or delay the bone age such that they may not match the child’s chronological age. Bone age is advanced in conditions where there are prolonged or elevated sex hormone levels such as precocious puberty, or in genetic overgrowth conditions such as Beckwith-Wiedemann syndrome. Bone age is delayed in constitutional growth delay, chronic ill health, endocrine disorders such as growth hormone deficiencies or hypothyroidism, genetic disorders such as Trisomy 21, Trisomy 18, and Turner’s syndrome. Obesity is unlikely to cause growth delay.

Juvenile myoclonic epilepsy is an epilepsy syndrome characterized by myoclonic jerks, generalized tonic-clonic seizures (GTCSs), and sometimes, absence seizures. The seizures of juvenile myoclonic epilepsy often occur when people first awaken in the morning. Seizures can be triggered by lack of sleep, extreme fatigue, stress, or alcohol consumption. Onset typically occurs around adolescence in otherwise healthy children. The causes of juvenile myoclonic epilepsy are very complex and not completely understood. Mutations in one of several genes, including the GABRA1 and the EFHC1 genes, can cause or increase susceptibility to this condition. Although patients usually require lifelong treatment with anticonvulsants, their overall prognosis is generally good.

Sepsis is a medical emergency that describes the body’s systemic immunological response to an infectious process that can lead to end-stage organ dysfunction and death. The fever, alongside the clinical presentation, make sepsis the likely diagnosis. A temperature >38 degrees in an infant <3months of age warrants investigation.

As there is lymphadenopathy already present in this patient, doing a biopsy of the lymph nodes will rule out metastasis of any underlying tumour.

The clinical scenario provided is highly suggestive of third-degree burns (or full-thickness burns) that may have invaded the deeper levels up to dermis, evident from the insensate nature of the lesion.Degrees of Burns:- First degree burns are superficial second-degree burns.- Second-degree burns are just deeper than that of first-degree burns but vary enormously in other properties.- Third-degree burns are full-thickness burns which are leathery in consistency, and insensate. These burns do not heal on their own. The sensory neurons present in the skin at the deeper levels are destroyed completely and hence provide a paradoxical lack of pain.- Fourth-degree burns involving the subcutaneous tissues, tendons, and bones are very difficult to manage.Assessment of the extent of the burns for the treatment employs specialized charts, such as Lund and Browder charts and Wallace rule of nines.The Lund and Browder chart is, however, considered the most accurate.Wallace’s Rule of Nines can be used for children >16 years: – Head + neck = 9%- Each arm = 9%- Each anterior part of leg = 9%- Each posterior part of leg = 9%- Anterior chest = 9%- Posterior chest = 9%- Anterior abdomen = 9%- Posterior abdomen = 9%

When topical agents are insufficient or not tolerated, or in cases of moderate to severe acne, especially when the chest, back and shoulders are involved, systemic antibiotics are often considered the next line of treatmentSystemic antibiotics should not be used to treat mild acne because of the risk of increasing resistance. The additional use of nonantibiotic topical agents in combination with oral antibiotics should be considered. Topical retinoids with oral antibiotics may give a faster response and be more effective than either drug used alone.Treatment with tetracyclines and erythromycin reduces P. acnes within the follicles, thereby inhibiting the production of bacterial-induced inflammatory cytokines. These agents also have inherent anti-inflammatory effects, such as suppressing leukocyte chemotaxis and bacterial lipase activity.

After birth, the infant takes its first breath and is exposed to a myriad of stimuli. The pulmonary vessels dilate, and pulmonary vascular resistance (PVR) decreases remarkably while the systemic vascular pressure rises above the PVR. This allows blood from the right ventricle to enter the lungs for oxygenation. In most cases, this increased oxygenation, along with other factors, causes the ductal wall to constrict and the ductus arteriosus to close functionally. As left-sided pressures rise higher than right-sided pressures, the foramen ovale functionally closes. With the clamping of the umbilical cord and the cessation of blood flow, pressures in the portal sinus decrease. This causes the muscle in the sinus wall near the ductus venosus to contract. The lumen of the duct becomes filled with connective tissue, and, in two months, the ductus venosus becomes a fibrous strand embedded in the wall of the liver, thus establishing adult circulation.

The most common cause of homonymous hemianopia (HH) is a stroke. In this condition there is bitemporal field loss. Lesions posterior to the optic chiasm, in the brain parenchyma are most likely to be the cause of the HH. In this case the retention of central vision indicates that the area of injury may be in the occipital cortex, sparing the occipital pole. The occipital pole receives sensory fibres from the macular, and has a dual blood supply protecting it from total infarction. Lesions of the optic tract can be ruled out as these cause total vision loss in the affected eye. Parietal or temporal nerve lesions cause affect the inferior and superior parts of the visual field respectively causing homonymous quadrantinopias.

Answer: Bochdalek herniaA Bochdalek hernia is one of two forms of a congenital diaphragmatic hernia, the other form being Morgagni hernia. A Bochdalek hernia is a congenital abnormality in which an opening exists in the infant’s diaphragm, allowing normally intra-abdominal organs (particularly the stomach and intestines) to protrude into the thoracic cavity. In the majority of patients, the affected lung will be deformed, and the resulting lung compression can be life-threatening. Bochdalek hernias occur more commonly on the posterior left side (85%, versus right side 15%).In normal Bochdalek hernia cases, the symptoms are often observable simultaneously with the baby’s birth. A few of the symptoms of a Bochdalek Hernia include difficulty breathing, fast respiration and increased heart rate. Also, if the baby appears to have cyanosis (blue-tinted skin) this can also be a sign. Another way to differentiate a healthy baby from a baby with Bochdalek Hernia, is to look at the chest immediately after birth. If the baby has a Bochdalek Hernia it may appear that one side of the chest cavity is larger than the other and or the abdomen seems to be scaphoid (caved in).Situs inversus (also called situs transversus or oppositus) is a congenital condition in which the major visceral organs are reversed or mirrored from their normal positions. The normal arrangement of internal organs is known as situs solitus while situs inversus is generally the mirror image of situs solitus. Although cardiac problems are more common than in the general population, most people with situs inversus have no medical symptoms or complications resulting from the condition, and until the advent of modern medicine it was usually undiagnosed. In the absence of congenital heart defects, individuals with situs inversus are homeostatically normal, and can live standard healthy lives, without any complications related to their medical condition. There is a 5–10% prevalence of congenital heart disease in individuals with situs inversus totalis, most commonly transposition of the great vessels. The incidence of congenital heart disease is 95% in situs inversus with levocardia.Cystic fibrosis is a progressive, genetic disease that causes persistent lung infections and limits the ability to breathe over time. In people with CF, mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene cause the CFTR protein to become dysfunctional. When the protein is not working correctly, it’s unable to help move chloride — a component of salt — to the cell surface. Without the chloride to attract water to the cell surface, the mucus in various organs becomes thick and sticky. In the lungs, the mucus clogs the airways and traps germs, like bacteria, leading to infections, inflammation, respiratory failure, and other complications. Necrotizing enterocolitis (NEC) is a medical condition where a portion of the bowel dies. It typically occurs in new-borns that are either premature or otherwise unwell. Symptoms may include poor feeding, bloating, decreased activity, blood in the stool, or vomiting of bile.The exact cause is unclear. Risk factors include congenital heart disease, birth asphyxia, exchange transfusion, and premature rupture of membranes. The underlying mechanism is believed to involve a combination of poor blood flow and infection of the intestines. Diagnosis is based on symptoms and confirmed with medical imaging.Morgagni hernias are one of the congenital diaphragmatic hernias (CDH), and is characterized by herniation through the foramen of Morgagni. When compared to Bochdalek hernias, Morgagni hernias are:-anterior-more often right-sided (,90%)-small-rare (,2% of CDH)-at low risk of prolapseOnly ,30% of patients are symptomatic. New-borns may present with respiratory distress at birth similar to a Bochdalek hernia. Additionally, recurrent chest infections and gastrointestinal symptoms have been reported in those with previously undiagnosed Morgagni hernia.The image of the transverse colon is herniated into the thoracic cavity, through a mid line defect and this indicates that it is a Morgagni hernia since the foramen of a Morgagni hernia occurs in the anterior midline through the sternocostal hiatus of the diaphragm, with 90% of cases occurring on the right side.Clinical manifestations of congenital diaphragmatic hernia (CDH) include the following:Early diagnosis – Right-side heart| decreased breath sounds on the affected side| scaphoid abdomen| bowel sounds in the thorax, respiratory distress, and/or cyanosis on auscultation| CDH can often be diagnosed in utero with ultrasonography (US), magnetic resonance imaging (MRI), or bothLate diagnosis – Chest mass on chest radiography, gastric volvulus, splenic volvulus, or large-bowel obstructionCongenital hernias (neonatal onset) – Respiratory distress and/or cyanosis occurs within the first 24 hours of life| CDH may not be diagnosed for several years if the defect is small enough that it does not cause significant pulmonary dysfunctionCongenital hernias (childhood or adult onset) – Obstructive symptoms from protrusion of the colon, chest pain, tightness or fullness the in chest, sepsis following strangulation or perforation, and many respiratory symptoms occur.

Immunoglobulin G (IgG) glomerular immune deposits are seen more commonly in HSP compared to IgA nephropathy.The presentation of the child is highly suggestive of Henoch-Schönlein 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 – 6years 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.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.

People who are at risk for severe illness and complications from measles, such as infants younger than 12 months of age, pregnant women without evidence of measles immunity, and people with severely compromised immune systems, should receive immunoglobulin. Intramuscular immunoglobulin should be given to all infants younger than 12 months of age who have been exposed to measles. For infants aged 6 through 11 months, MMR vaccine can be given in place of IG, if administered within 72 hours of exposure.

History of fever is suggestive of an infective focus. A straight nasal bones excludes a nasal bone fracture. A nasal septal abscess is defined as a collection of pus between the cartilage or bony septum and it is an uncommon disease which should be suspected in a patient with acute onset of nasal obstruction and recent history of nasal trauma.

Celiac disease has characteristic shortened intestinal villi. When patients with celiac disease eat products containing gluten, they are unable to absorb the nutrients due to flattened or shortened intestinal villi. The blistering rash present on the patient’s elbows strongly suggests celiac disease. This rash is a sign of the condition Dermatitis Herpetiformis which is associate with celiac disease. Therefore, it is also often called ‘gluten rash’.

Recommended regimens3 NRTI (e.g., zidovudine, lamivudine, abacavir) OR2 NRTI (e.g., lamivudine + abacavir) AND1 NNRTI (e.g., efavirenz) OR1 PI (e.g., lopinavir) OR1 INI (e.g., raltegravir)

Bleeding oesophageal varices secondary to portal hypertension can cause a massive gastrointestinal haemorrhage resulting in shock. Perforated ulcer is less likely in this age group. Mallory Weiss tear would not likely result in a massive haemorrhage. Aorto-intestinal fistula is more common in older patients with abdominal aneurysms. Boerhaave’s syndrome is a result of a ruptured oesophagus following excessive vomiting.

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.

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.

Certain infections and medications cause characteristic skin lesions, which are the result of hypersensitivity reactions to these agents. A skin rash characterized by the eruption of macules, papules, and target-like circular lesions is referred to as erythema multiforme. The target or iris lesions appear rounded with a red centre surrounded by a pale ring, which in turn is surrounded by a dark red outer ring. These are acute and self-limiting with a propensity for distal extremities. The most common infectious cause is the infection with herpes simplex virus 1 and 2 to a lesser extent. Other notable infectious causes of erythema multiforme include Mycoplasma pneumoniae, cytomegalovirus, HIV, hepatitis c virus, varicella zoster virus, adenovirus, and some fungal infections. Norovirus infection has not been implicated in the aetiology of erythema multiforme.

Haemophilia A has an X-linked recessive pattern of inheritance, meaning that is a 50% chance of having a son with haemophilia and 50% chance of the daughters being carriers of the haemophilia gene.

Constipation is often associated with nocturnal enuresis in children. The palpable mass is the impacted stool. The decreased appetite is common in those with constipation.

Thyroglossal cyst is the most common congenital thyroid anomaly which is clinically significant and affects women more than men. It is a vestigial remnant of developing thyroid. Although the thyroglossal cyst can develop anywhere along the thyroglossal duct, the most common site is in the midline between the isthmus of thyroid and hyoid bone, or just above the hyoid. Thyroglossal cysts are also associated with ectopic thyroid tissue. Clinically, the cyst moves upward with protrusion of the tongue. Rarely, the persistent duct can become malignant (thyroglossal duct carcinoma) where the cancerous cells arise in the ectopic thyroid tissue that are deposited along the duct. Exposure to radiation is a predisposing factor.

The patient is most likely suffering from obstructive jaundice. Ultrasound of the abdomen is the superior diagnostic tool in detecting and assessing biliary system obstruction, because it is easy, available, accurate and non-invasive.

Intussusception is a condition in which one segment of intestine telescopes inside of another, causing an intestinal obstruction. Although intussusception can occur anywhere in the gastrointestinal tract, it usually occurs at the junction of the small and large intestines. Most describe the symptoms of intussusception as a triad of colicky abdominal pain, bilious vomiting, and currant jelly stool. The primary symptom of intussusception is described as intermittent crampy abdominal pain.

The most probable cause for the child’s presenting symptoms and the findings in ultrasound would be the presence of an abnormal posterior urethral valve. A posterior urethral valve is a developmental anomaly that usually affects male infants (incidence 1 in 8000) leading to obstructive uropathy. Diagnostic features include bladder wall hypertrophy, hydronephrosis and bladder diverticula.Note:Posterior urethral valves are the most common cause of infra-vesical outflow obstruction in males. They can be diagnosed on antenatal ultrasonography. Due to the necessity of the fetal bladder to develop high emptying pressures in utero secondary to this anomaly, the child may develop renal parenchymal damage. This leads to renal impairment noted in 70% of boys at the time of presentation. Management:The immediate treatment would be to place a bladder catheter to relieve the acutely retained urine. The definitive treatment of choice would be an endoscopic valvotomy with a cystoscopic and renal follow up.