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.

One of the features of pyloric stenosis is hypochloraemic, hypokalaemic metabolic alkalosis. In emergency settings, capillary blood gas is the easiest and fastest way to establish a sustainable suspicion of pyloric stenosis. However, all tests are useful for the diagnosis of the condition.

Marfan syndrome is a disorder that affects the connective tissue in many parts of the body. Connective tissue provides strength and flexibility to structures such as bones, ligaments, muscles, blood vessels, and heart valves. The signs and symptoms of Marfan syndrome vary widely in severity, timing of onset, and rate of progression.This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.At least 25 percent of Marfan syndrome cases result from a new mutation in the FBN1 gene. These cases occur in people with no history of the disorder in their family.The two primary features of Marfan syndrome are vision problems caused by a dislocated lens (ectopia lentis) in one or both eyes and defects in the large blood vessel that distributes blood from the heart to the rest of the body (the aorta).Associations include:Tall statureLearning disability (50%)Lens subluxation (usually upwards)Femoral herniaHemivertebraeCardiac problems (Aortic/mitral regurgitation, aneurysms)Joint hypermobilityArachnodactyly

Based on the clinical scenario, the most likely underlying pathogen is the Epstein Barr virus (EBV).An Epstein Barr virus (EBV) infection most commonly results in upper respiratory tract symptoms with fever and sore throat. Lymphadenopathy is frequently palpable on examination. Splenomegaly may also occur, and for this reason, patients diagnosed with glandular fever should be advised to avoid contact sports for one month following diagnosis. The presence of petechiae on the soft palate is also associated with EBV infection. The vast majority of patients with active EBV infection will develop a widespread rash if given amoxicillin, therefore, phenoxymethylpenicillin (Penicillin V) is recommended for the treatment of a suspected bacterial throat infection to prevent this complication occurring for individuals who have EBV infection.Other options:- Coronavirus: This is one of the causes of the common cold and is frequently responsible for sore throats| however, in this case, the presenting features are more suggestive of an EBV infection.- Group A Streptococcus: Streptococci are classified into two main groups| alpha-haemolytic and beta-haemolytic. Group A Streptococcus belongs to the beta-haemolytic group. Group A streptococcal infection is a common cause of bacterial tonsillitis. It is possible that the child, in this case, had streptococcal tonsillitis and has had a drug reaction to the amoxicillin. However her age, flu-like symptoms and petechiae on her palate all point to an EBV infection and amoxicillin resulting in a rash.- Parainfluenza: Parainfluenza viruses are one of many causes of the common cold and can cause pharyngitis. They are the leading cause of viral croup.- Rhinovirus: Rhinoviruses are one of many causes of the common cold and are frequently responsible for sore throats| however, in this case, are other factors suggesting EBV infection.

The boy seems to have a varicocele so the most appropriate next step would be reassurance. A varicocele is an enlargement of the veins within the scrotum called the pampiniform plexus. A varicocele only occurs in the scrotum and is very similar to varicose veins that can occur in the leg. Because a varicocele usually causes no symptoms, it often requires no treatment.

The type of significance test used depends on whether the data is parametric (can be measured, usually normally distributed) or non-parametric.
Parametric tests:
Student’s t-test – paired or unpaired*
Pearson’s product-moment coefficient – correlation

Non-parametric tests:
Mann-Whitney U test – unpaired data
Wilcoxon signed-rank test – compares two sets of observations on a single sample
chi-squared test – used to compare proportions or percentages
Spearman, Kendall rank – correlation.

The outcome measured is not normally distributed, i.e. it is non-parametric. This excludes the Student’s t-tests. We are not comparing percentages/proportions so the chi-squared test is excluded. The Mann–Whitney U test is a nonparametric test of the null hypothesis that it is equally likely that a randomly selected value from one sample will be less than or greater than a randomly selected value from a second sample.
This test can be used to investigate whether two independent samples were selected from populations having the same distribution.

Hereditary diseases follow specific inheritance patterns according to the type of gene involved. Mutations in the genes which are on the sex chromosome, chromosome X are called X-linked diseases. X-linked recessive conditions result when both the copies of X-chromosomes are defective, which happens in the case of females since males have only one X- chromosome. Thus, these conditions are more common among males, and examples include colour blindness, haemophilia, Lesch-Nyhan syndrome, and hunter’s syndrome, etc. Hunter’s syndrome is a type of lysosomal storage disease which is also known as mucopolysaccharidosis II. Vitamin D resistant rickets is a X-linked dominant disease. Neurofibromatosis type 1 and 2 are autosomal dominant conditions while Wilson’s disease is autosomal recessive.

The heart is the first organ to form and become functional, emphasizing the importance of transport of material to and from the developing infant. It originates about day 18 or 19 from the mesoderm and begins beating and pumping blood about day 21 or 22. It forms from the cardiogenic region near the head and is visible as a prominent heart bulge on the surface of the embryo. Originally, it consists of a pair of strands called cardiogenic cords that quickly form a hollow lumen and are referred to as endocardial tubes. These then fuse into a single heart tube and differentiate into the truncus arteriosus, bulbus cordis, primitive ventricle, primitive atrium, and sinus venosus, starting about day 22. The primitive heart begins to form an S shape within the pericardium between days 23 and 28. The internal septa begin to form about day 28, separating the heart into the atria and ventricles, although the foramen ovale persists until shortly after birth. Between weeks five and eight, the atrioventricular valves form. The semilunar valves form between weeks five and nine.

Tooth extraction or any surgical procedure may introduce bacteria into the blood stream. The most commonly involved organisms include Staphylococcus aureus and Streptococcus viridans. Once in the blood, these organisms have a very high tendency of attaching to the walls of the heart and causing inflammation known as endocarditis.

Based on the findings presented, the sign elicited is Rovsing’s sign.Rovsing’s sign:It is a sign suggestive of appendicitis. A positive sign is determined when palpation in the left lower quadrant of a patient’s abdomen causes pain in the right lower quadrant.Other options:- Murphy’s sign is positive in gallbladder inflammation. With the upper border of the examiner’s hand in the right upper quadrant of the abdomen under the rib cage, the patient is asked to inhale. Inhalation causes the gallbladder to descend, which catches on the fingers, causing pain.- Cullen’s sign is suggestive of ectopic pregnancy or acute pancreatitis and describes the bruising around the umbilicus.- Tinel’s sign is positive in those with carpal tunnel syndrome. The examiner’s fingers tap the median nerve over the flexor retinaculum, which causes paraesthesia over the distribution of the median nerve.- Battles’ sign describes bruising behind the ear, suggesting a basal skull fracture of the posterior cranial fossa.

This clinical picture is typical of chickenpox, which is treated with antihistamines and calamine lotion. In the case of fever, acetaminophen can be used. Generally treatment is purely for symptomatic relief.

Congenital duodenal atresia is one of the more common intestinal anomalies treated by paediatric surgeons, occurring 1 in 2500-5000 live births. In 25-40% of cases, the anomaly is encountered in an infant with trisomy 21 (Down syndrome).Presenting symptoms and signs are the results of high intestinal obstruction. Duodenal atresia is typically characterized by the onset of vomiting within hours of birth. While vomitus is most often bilious, it may be nonbilious because 15% of defects occur proximal to the ampulla of Vater. Occasionally, infants with duodenal stenosis escape detection of an abnormality and proceed into childhood or, rarely, into adulthood before a partial obstruction is noted. Nevertheless, one should assume any child with bilious vomiting has a proximal GI obstruction until proven otherwise, and further workup should be begun expeditiously.Once delivered, an infant with duodenal atresia typically has a scaphoid abdomen. One may occasionally note epigastric fullness from dilation of the stomach and proximal duodenum. Passing meconium within the first 24 hours of life is not usually altered. Dehydration, weight loss, and electrolyte imbalance soon follow unless fluid and electrolyte losses are adequately replaced. If intravenous (IV) hydration is not begun, a hypokalaemic/hypochloraemic metabolic alkalosis with paradoxical aciduria develops, as with other high GI obstruction. An orogastric (OG) tube in an infant with suspected duodenal obstruction typically yields a significant amount of bile-stained fluid.

Based on the clinical scenario, the boy is going through normal pubertal changes.In the 3 years before puberty, low pulsatile LH levels become detectable during sleep. LH and FSH are produced in the anterior pituitary and released due to pulsatile gonadotrophin-releasing hormone (GnRH) secreted by the hypothalamus. There is an increase in the amplitude and frequency of LH secretion as puberty approaches, which causes enlargement of the gonads. In boys, the testicles produce testosterone, and in girls, the ovaries produce oestradiol and ovarian androgens, which, with the adrenal androgens, produce secondary sexual characteristics.Note:The average age at onset of puberty is 11 years in girls. The first sign is breast bud development, followed by the appearance of pubic hair 6–12 months later. Menarche usually occurs 2–2.5 years after breast bud development. Peak height velocity in girls occurs at breast stage 2–3 and virtually always precedes menarche. The onset of puberty in boys is at 11.5 years. The first sign is testicular enlargement (>3 ml) and thinning of the scrotum. This is followed by the pigmentation of the scrotum and growth of the penis, and pubic hair follows. Peak height velocity (growth spurt) is two years later in boys than in girls and occurs at testicular stage 4–5 (i.e. testicular volume 10–12 ml), which is around 13–14 years of age. Breast enlargement occurs in 40–60% of boys (rarely, significant enough to cause social embarrassment in 10%) and is a result of oestradiol produced by the metabolism of testosterone. It usually resolves within three years. During puberty, elongation of the eye often occurs, causing short-sightedness.

The sign being elicited in this patient is Nikolsky’s sign. Based on the findings, the patient is suffering from toxic epidermal necrolysis.Nikolskys sign: Rubbing the skin causes exfoliation of the outer layer and usually blistering within a few minutes. Other options:- Cullen’s sign: Periumbilical bruising due to intra-abdominal haemorrhage. If the discolouration is seen in the flanks, it is called Cullen’s sign. Underlying pathology includes ruptured ectopic pregnancy and haemorrhagic pancreatitis. – Forscheimer’s sign: It is a fleeting exanthem that is seen as small, red spots (petechiae) on the soft palate. Associated with rubella and glandular fever. Gorlin’s sign: It is the ability to touch the tip of the nose with the tongue. Increased incidence in children with connective tissue disorders, e.g. Ehler Danlos syndrome. – Auspitzs sign: These are small bleeding points left behind when psoriatic scales are lifted off. It is not a very sensitive or specific sign. Other cutaneous signs include:- Hair collar sign: It is a collar of hypertrichosis around an area of cranial dysraphism.- Hertoghe’s sign (Queen Anne’s sign): It is the loss of lateral one-third of eye-brows. It is associated with numerous conditions, including lupus, HIV, and hypothyroidism. – Dariers sign: It is the swelling, itching and erythema that occurs after stroking skin lesions of a patient with systemic mastocytosis or urticarial pigmentosa. – Dermatographism: Rubbing the skin causes a raised, urticarial lesion. – Koebners phenomenon: It is the appearance of new skin lesions in areas of trauma.- Breakfast, lunch, and dinner sign: Linear pathway of a group of three to five papules caused by the common bed bug, Cimex lectularius. – Buttonhole sign: In type 1 neurofibromatosis, neurofibromas can be invaginated with the finger back into the subcutis. The nodule will reappear after the release of pressure. The sign is also positive for dermatofibromas. – Crowe’s sign: Axillary freckling seen in type I neurofibromatosis.

An enlarged lymph node does not necessarily need treatment especially if it is caused by a virus. If it is bacterial, antibiotics should be prescribed. Amoxicillin is first line treatment in non-penicillin allergic patients and side effects include allergic reactions like skin rash and itching

Epilepsy is a common paediatric neurologic disorder characterized by seizures of varying frequency and intensity. There are many childhood or infantile epilepsy syndromes that can be categorized as benign epilepsy syndromes as the child suffering from these usually outgrows them after reaching a certain age, and they do not lead to significant cognitive or physical impairment. Some of these may not need any treatment. Such benign epilepsy syndromes include benign rolandic epilepsy, Panayiotopoulos syndrome, Gastaut type-idiopathic childhood occipital epilepsy, and idiopathic photosensitive occipital lobe epilepsy. West syndrome, also called infantile spasms, is a serious infantile epileptic encephalopathy, characterized by multiple clusters of myoclonic spasms, and regression of the previous normally attained milestones. It is associated with severe cognitive and physical impairment, often leading to life long disability.

The clinical presentation and way the boy ‘climbs up’ his legs to get up from a supine position (Gowers’ sign) suggests proximal muscle weakness secondary to dermatomyositis.Dermatomyositis is an inflammatory myopathy that typically presents between the ages of five years and ten years. The onset is insidious, and the proximal muscle weakness and raised creatine kinase might be mistaken for muscular dystrophy. However, the systemic illness and rash are characteristic features of the condition.

Point mutations are the type of mutations in which only a single nucleotide of the DNA is either deleted, substituted or a new single nucleotide is inserted into the DNA, causing alterations in the original normal DNA sequencing. The examples of point mutations include hemochromatosis, sickle cell disease, and Tay-Sach’s disease. Huntington’s disease is a trinucleotide repeat disorder. Down’s syndrome is characterized by an extra copy of chromosome 21, while Klinefelter syndrome is marked by an extra X chromosome. Fragile X syndrome is also a trinucleotide repeat disorder.

Exposure to excessive androgens is usually accompanied by premature epiphyseal maturation and closure, resulting in a final adult height that is typically significantly below that expected from parental heights. congenital adrenal hyperplasia (CAH) is associated with precocious puberty caused by long term exposure to androgens, which activate the hypothalamic-pituitary-gonadal axis. Similarly, CAH is associated with hyperpigmentation and hyperreninemia due to sodium loss and hypovolaemia.

Becker’s muscular dystrophy is a disease characterised by progressive weakness and wasting of the skeletal and cardiac muscles. It is inherited and primarily affects males.

Coarctation of the aorta may be defined as a constricted aortic segment that comprises localized medial thickening, with some infolding of the medial and superimposed neointimal tissue.The presence of associated defects and aortic arch anomalies, the extent of patency of the ductus arteriosus, the rapidity of the process of closure of the ductus arteriosus, and the level of pulmonary vascular resistance determine the timing of clinical presentation and the severity of symptoms. Young patients may present in the first few weeks of life with poor feeding, tachypnoea, and lethargy and progress to overt CHF and shock. These patients may have appeared well before hospital discharge, and deterioration coincides with closure of the patent ductus arteriosus. Presentation may be abrupt and acute with ductal closure.Neonates may be found to have tachypnoea, tachycardia, and increased work of breathing and may even be moribund with shock. Keys to the diagnosis include blood pressure (BP) discrepancies between the upper and lower extremities and reduced or absent lower extremity pulses to palpation. However, when the infant is in severe heart failure, all pulses are diminished.The murmur associated with coarctation of the aorta may be nonspecific yet is usually a systolic murmur in the left infraclavicular area and under the left scapula.

Lead can be found in material used for mining, leaded paints and gasoline, glassware, toys, and even cosmetics. Lead poisoning is rare nowadays as the use of lead has been banned from many products. Lead is toxic and in certain concentrations can cause irreversible damage. Children are especially vulnerable as they absorb 4 times as much ingested lead as adults. The typical features of lead poisoning include developmental delay and behavioural disorders, microcytic anaemia, constipation and vomiting. Pulmonary fibrosis, Osteomalacia and cardiomyopathy are not known features of lead poisoning.

Puberty is a period of transitioning into adulthood by developing full reproductive potential by undergoing drastic physiological and psychological changes. For boys, it occurs around 9-16 years of age typically. The process of pubertal changes is usually divided into stages called tanner’s stages. The physiologic changes of puberty are initiated by the release of gonadotropin-releasing hormones from the hypothalamus, which then interact with numerous endogenous and environmental stimuli to bring about the physical pubertal features. Tanner stage 2 in boys is characterized by the thinning and reddening of the scrotal skin.The growth spurt of around 9cm per year is expected in boys, at the peak velocity.Testicular enlargement of >3cm commences puberty.Pubarche, in the absence of other secondary sexual characteristics, is pathological.Adrenarche is the increase in the secretion of adrenal androgens, occurring prior to increased gonadotropin release.

The patient’s history points to absence seizures. Carbamazepine has been shown to aggravate generalized seizure types, especially absence seizures, because it acts directly on the ventrobasal complex of the thalamus which is critical to the neurophysiology of absence seizures.

Milestones of 6 monthsSocial and EmotionalKnows familiar faces and begins to know if someone is a stranger Likes to play with others, especially parents Responds to other people’s emotions and often seems happy Likes to look at self in a mirror Language/CommunicationResponds to sounds by making sounds Strings vowels together when babbling (“ah,” “eh,” “oh”) and likes taking turns with the parent while making sounds Responds to own name Makes sounds to show joy and displeasure Begins to say consonant sounds (jabbering with “m,” “b”) Cognitive (learning, thinking, problem-solving)Looks around at things nearby Brings things to mouth Shows curiosity about things and tries to get things that are out of reach Begins to pass things from one hand to the other Movement/Physical DevelopmentRolls over in both directions (front to back, back to front) Begins to sit without support When standing, supports weight on legs and might bounce Rocks back and forth, sometimes crawling backwards before moving forward

Aniridia is a genetic condition characterized by defects in the formation of a normal iris. The iris may be completely absent or only partially. One of the types of aniridia may be associated with other abnormalities like cataracts, glaucoma, corneal clouding, and nystagmus. The third type of aniridia is associated with intellectual disability, while a fourth type occurs in association with Wilm’s tumour. Aniridia may also be associated with amblyopia and buphthalmos, but macular hypoplasia is not a feature.

Deaths by age group: 60% <1 year - due mainly to congenital, neonatal, and infection related problems.10% 1-4 years - due to accident (15%), cancer (15%), or congenital problems (14%)18% 15-19 years - accidental (42%) accidents reflect increased risk taking

Bacterial meningitis (including meningococcal meningitis, Haemophilus influenzae meningitis, and staphylococcal meningitis) is a neurologic emergency that is associated with significant morbidity and mortality. Initiation of empiric antibacterial therapy is therefore essential for better outcomes. The patient appears to be suffering from meningitis caused by Staphylococcus aureus. Methicillin would be the drug of choice . It is bactericidal and unlike streptomycin and chloramphenicol it is not associated with toxicity

Live attenuated vaccines such as the MMR, should be avoided in HIV+ patients.

Cranial nerve II (CN II or optic nerve) runs along the midline of the ventral surface of the brain and conveys visual information from the retina of each eye to the corresponding region of the primary visual cortex. The right half of the visual field of both eyes is processed by the left half of the retina, while the right half of the retina processes the left half of the visual field. These retinal ganglion cells project myelinated axons, carrying CN II sensory afferent fibres, through the optic chiasm, where optic nerve fibres from the nasal half of each retina decussate to the contralateral side of the brain for processing. After passing through the optic chiasm, the optic nerve becomes the optic tract that synapses to the lateral geniculate nucleus (LGN) of the thalamus and subsequently projects optic radiations to the primary visual cortex (V1) of the occipital lobe. The optic tract also projects to the superior colliculus, pretectal nuclei, and suprachiasmatic nuclei. This part of the optic pathway serves the important light reflex.Due to the anatomical location of the optic chiasm superior to the pituitary gland, a suprasellar extension of a pituitary macroadenoma will lead to compression of the optic nerve fibres decussating at the optic chiasm. Impingement of these nerves prevents visual information from the temporal visual fields of each eye from reaching the processing centres in the brain, leading to peripheral vision loss