Haemolytic-uremic syndrome (HUS) is a clinical syndrome characterized by progressive renal failure that is associated with microangiopathic (nonimmune, Coombs-negative) haemolytic anaemia and thrombocytopenia. HUS is the most common cause of acute kidney injury in children. It predominantly occurs in infants and children after prodromal diarrhoea. In summer epidemics, the disease may be related to infectious causes.Bacterial infections may include the following:S dysenteriaeE ColiSalmonella typhiCampylobacter jejuniYersinia pseudotuberculosisNeisseria meningitidisS pneumoniaLegionella pneumophilaMycoplasma speciesRickettsial infections may include Rocky Mountain spotted fever and microtatobiotesViral infections may include the following:Human immunodeficiency virus (HIV)CoxsackievirusEchovirusInfluenza virusEpstein-Barr virusHerpes simplex virusFungal infections can include Aspergillus fumigatus.Vaccinations may include the following:Influenza triple-antigen vaccineTyphoid-paratyphoid A and B (TAB) vaccinePolio vaccinePregnancy-associated HUS occasionally develops as a complication of preeclampsia. Patients may progress to full-blown haemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome. Postpartum HUS usually occurs within 3 months of delivery. The prognosis is poor, with a 50-60% mortality rate, and residual renal dysfunction and hypertension occur in most patients.

Intussusception is the invagination of one segment of the intestine within a more distal segment. It presents with vomiting, abdominal pain, and a palpable abdominal mass.Intussusception usually affects infants between 6-18 months old. Boys are affected twice as often as girls

Hematopoietic stem cells (HSCs) are a rare population of cells residing in the bone marrow (BM) and continuously replenish all mature blood cells throughout their life span.

Rhabdomyosarcoma originates from skeletal muscle cells. A biopsy is needed for grading according to microscopy. Most patients are adult females.

In an acute and severe asthma attack the child cannot complete sentences in one breath because they are too breathless. The O2 saturation is less than 92% and PEF is between 33-50% best or predicted. In children that are 2-5 years old, HR is more than 140 bpm and more than 125 bpm in those older than 5 years old. The RR in children between 2-5 years old is more than 40/min, and more than 30/min in those older than 5 years old.

Ehlers-Danlos Syndrome (EDS) is a group of genetic connective tissue disorders with over 13 clinical subtypes. Hyper-mobility is common to many of these subtypes. Vascular EDS is identified by thin, translucent skin prone to easy bleeding, as well as the risk of early arterial rupture, gastrointestinal perforation and uterine rupture. Those affected have dysmorphic features including a thin nose and lips, sunken cheeks and large eyes. The other features including; atrophic scars, a dominant family history, hyper extensible skin and kyphoscoliosis are not specific to vascular EDS and overlap in many of the subtypes.

Precocious puberty is the development of secondary sexual characteristics before the age of 8 in females, and 9 in males. The first sign of early puberty in females is breast enlargement, followed by the appearance of pubic and axillary hair, and finally menarche, 2-3 years after the onset of thelarche. Precocious puberty is caused by the premature activation of the hypothalamic-pituitary-gonadal axis where FSH and LH levels are raised. Less common is the gonadotrophin independent form, which is due to excess sex hormones, but low FSH and LH levels.

The symptoms of a partial generalized seizure are consistent with this patient.

Hyperkalaemia presents with high voltage (peaked) T waves on ECG. Other features on ECG include smaller p-waves and wider QRS complexes.

Intussusception is the most suggested case here based on the child’s symptoms. The urgent course of treatment is to bring the child to a paediatric surgical unit. If air reduction attempts fail, surgery will have to be done. Risk factors for intussusception include viral infection and intestinal lymphadenopathy.

The drainage of cerebral spinal fluid from the third ventricle to the fourth ventricle is carried out by the cerebral aqueduct. The cerebral aqueduct is the narrowest passageway in the entire ventricular system and thus forms the most common site of blockage of flow of cerebrospinal fluid. The interventricular foramen allows passage of CSF to the third ventricle. The foramen of Luschka and Magendie are located on the fourth ventricle and allow passage of CSF to the subarachnoid space from the ventricular system. The pontine cistern is a space located on the ventral aspect of the pons. The cisterna magna is an opening on the subarachnoid space between the pia matter and the arachnoid.

Vesicoureteral reflux is a common disorder in children but can result in kidney scarring following acute pyelonephritis. The gold standard diagnostic test to detect renal scars in children is 99mTc-dimercaptosuccinic acid (DMSA) scintigraphy

The rational part of a teen’s brain isn’t fully developed until the age of 25 or so.In fact, recent research has found that adult and teen brains work differently. Adults think with the prefrontal cortex, the brain’s rational part. This is the part of the brain that responds to situations with good judgment and an awareness of long-term consequences. Teens process information with the amygdala. This is the emotional part.

The most common organism responsible for tinea capitis is Trichophyton tonsurans.Tinea is a term given to dermatophyte fungal infections. There are three types of tinea, depending on what part of the body is infected:- Tinea capitis – scalp- Tinea corporis – trunk, legs or arms- Tinea pedis – feet-Tinea capitis (scalp ringworm): It is a cause for scarring alopecia mainly seen in children. If untreated, it can form a raised pustular, spongy/boggy mass called a kerion. The most common cause of tinea capitis in the UK and the USA is Trichophyton tonsurans. Tinea can also be caused by Microsporum canis acquired from cats or dogs.The diagnosis of tinea capitis and identification of the organism is possible from the skin lesions: – Scalp scrapings and Potassium hydroxide (KOH) mounts.- Wood’s lamp: Microsporum canis produces a green fluorescence under Wood’s lamp examination.Treatment: – Oral antifungals: terbinafine for Trichophyton tonsurans infections.- Griseofulvin for Microsporum infections. – Topical ketoconazole shampoo is recommended for the first two weeks to limit the transmission of the infection.

Hirsutism is the growth of excess hair in androgen dependent areas or in a male pattern. The phenomenon is found in conditions where there is abnormal androgen action. This can occur in adrenal lesions including congenital adrenal hyperplasia, and Cushing syndrome, or a failure to produce adequate female hormones such as PCOS and premature menopause. Similarly, drugs such as anabolic steroids, danazol and minoxidil can also cause hirsutism. Delayed puberty is unlikely to cause hirsutism.

The glossopharyngeal nerve is the primary sensory nerve for the tonsillar fossa. The lesser palatine nerve makes a smaller contribution. Because of this, otalgia may occur following tonsillectomy.Anatomical Rationale:Each palatine tonsil has two surfaces, a medial surface which projects into the pharynx and a lateral surface that is embedded in the wall of the pharynx.The primary arterial supply is from the tonsillar artery, a branch of the facial artery. Its veins pierce the constrictor muscle to join the external palatine or facial veins. The external palatine vein is immediately lateral to the tonsil, which may result in bleeding during a tonsillectomy.Lymphatic drainage is the jugulodigastric node and the deep cervical nodes.TonsillitisThe inflammation of tonsils is usually due to bacterial aetiology (50%) – group A Streptococcus, the remainder of the causes are viral.May be complicated by the development of an abscess (quinsy), which may distort the uvula.Indications for tonsillectomy include recurrent acute tonsillitis, and enlargement causing sleep apnoea.Dissection tonsillectomy is the preferred technique with haemorrhage being the most frequent complication. Delayed otalgia may occur owing to irritation of the glossopharyngeal nerve.

Pulmonary surfactant is a lipoprotein complex that is responsible for preventing the collapse of alveoli and increasing lung compliance.It is produced in the endoplasmic reticulum and secreted from the lamellar bodies of type 2 pneumocytes.Surfactant is essential for reducing surface tension at the air-water interface in the alveoli, thus preventing the collapse of alveoli during expiration. It is composed of dipalmitoyl phosphatidylcholine (DPPC), which is a phospholipid.In fetal development, production of surfactant begins around 26 weeks of gestation and reaches mature levels by 35 weeks.The deficiency of surfactant can result in neonatal respiratory distress syndrome or hyaline membrane disease, particularly in premature new-born babies.

Among the provided options, we would expect a normally developing six-month-old child to have lost Moro’s reflex.Note:The Moro reflex is present from birth and persists until 4 months of age. It is abnormal for the Moro reflex to persist much beyond this stage, and if it does, cerebral palsy should be considered.A normal 6-month old baby should be able to roll over from front to back, readily follow objects with their eyes, transfer objects from hand to hand, recognise parental voices and babble and laugh.Other options:- Having a pincer grip is more typical of a 9-12-month-old.- Although at 6 months babies are often able to sit briefly or with support, sitting steadily is typically seen at 9 months.- Starting to stand with support is more typical of a 9-12-month-old.- Waving bye-bye is more typical of a 9-12-month-old.

Human breast milk composition changes with the progressive age of the infant. Breastmilk produced for a preterm baby often has a higher caloric content than breastmilk for a term baby. After the production of colostrum in the first days of life, the milk continues to mature. by week 4-6 milk can be considered fully mature. The average calories found in mature breastmilk are about 70kcal/100ml

Hassall’s corpuscles are groups of epithelial cells within the thymic medulla. The physical nature of these structures differs between mammalian species. Although Hassall’s corpuscles have been proposed to act in both the removal of apoptotic thymocytes and the maturation of developing thymocytes within the thymus, the function of Hassall’s corpuscles has remained an enigma.

Oligomenorrhoea and BMI of 40.4 is suggestive of Polycystic ovary syndrome (PCOS). To diagnose PCOS 2 out of following 3 criteria should be present : oligo/anovulation, hyperandrogenism, clinical (hirsutism or less commonly male pattern alopecia) or biochemical (raised FAI or free testosterone) and polycystic ovaries on ultrasound.

Most healthy infants and children grow predictably, following a typical pattern of progression in weight, length, and head circumference. Normal human growth is pulsatile; periods of rapid growth (growth spurts) are separated by periods of no measurable growth Growth hormone levels and responsiveness’ develop in late infancy, increase during childhood and peak during puberty.Typical milestones – General guidelines regarding length or height gain during infancy and childhood include the following:- The average length at birth for a term infant is 20 inches (50 cm)- Infants grow 10 inches (25 cm) during the first year of life- Toddlers grow 4 inches (10 cm) between 12 and 24 months, 3 inches (7.5 cm) between 24 and 36 months, and 3 inches (7.5 cm) between 36 and 48 months- Children reach one-half of their adult height by 24 to 30 months- Children grow 2 inches per year (5 cm per year) between age four years and puberty- There is a normal deceleration of height velocity before the pubertal growth spurt.Growth continues past pubertal growth spurt as there is increase in spinal length.

NICE guidelines suggest that when a child’s single risk factor is 2 vomits, the child should be observed for 4 hours from the time of the injury, instead of having a CT.

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.

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

Logistic regression analysis is an easy to use regression that can serve to estimate how a binary or dichotomous dependent variable, for example whether or not a student passes or fails a medical exam, is related to the number of hours the student studies for the exam. This regression is able to yield an odds ratio, i.e. the probability of passing the exam based on each additional hour of study. As stated, the outcome does not need to be normally distributed but is usually binary. This type of analysis is not complex and does not need to be avoided as it is available most statistical packages.

Renal stones < 5mm generally pass spontaneously with adequate fluid intake. Stones 5mm-10mm with pain not resolving, require medical expulsive therapy with Nifedipine or Tamsulosin. For stones larger than 10mm, ESWL or Ureteroscopy is indicated. For stones as big as 2cm, percutaneous nephrolithotomy should be applied.

Sepsis can be described as a condition in which there is a dysregulated inflammatory response to an infection. In the case of neonates, sepsis can be life threatening and may present with respiratory distress more than 4 hours after birth, shock, seizures, and multi organ failure. Risk factors that further point to sepsis include prolonged rupture of maternal membranes for more than 24 hours before birth, a history of a maternal fever during labour, or parenteral antibiotic treatment given to the mother for a suspected or confirmed bacterial infection.

Based on the presented clinical scenario, the most probable diagnosis for the patient would be testicular torsion.Rationale:The gubernaculum is the structure responsible for aiding the descent of the testicles from the abdomen into the scrotum. The processus vaginalis precedes the descent of the testes and then undergoes closure. Abnormalities such as the persistence of a patent processus vaginalis, known as bell clapper deformity, predispose to testicular torsion.Other options:- Varicocele: Nutcracker syndrome occurs where the left renal vein becomes compressed in between the superior mesenteric artery and the aorta. Since the left gonadal vein drains into the left renal vein, this results in a varicocele. – Epididymitis and mumps orchitis are differentials for acute testicular pain but are not due to a defect in the processus vaginalis. – An incarcerated inguinal hernia presents mainly with signs of bowel obstruction which are not mentioned in the clinical scenario.The descent of testes:- Until the end of foetal life, the testicles are located within the abdominal cavity. – They are initially located on the posterior abdominal wall on a level with the upper lumbar vertebrae (L2). – Attached to the inferior aspect of the testis is the gubernaculum testis which extends caudally to the inguinal region, through the canal and down to the superficial skin. – It is interesting to note that both the testis and the gubernaculum are extra-peritoneal.- As the foetus grows, the gubernaculum becomes progressively shorter. It carries the peritoneum of the anterior abdominal wall (the processus vaginalis). As the processus vaginalis descends the testis is guided by the gubernaculum down the posterior abdominal wall and the back of the processus vaginalis into the scrotum.- By the third month of foetal life the testes are located in the iliac fossae, by the seventh they lie at the level of the deep inguinal ring.Usually, the processus vaginalis closes after birth but may persist predisposing to indirect hernias. On the other hand, a partial closure may result in the development of cysts on the cord.

Lypohypertrophy is the most common skin-related complication of insulin injection.