Answer: Spontaneous bacterial peritonitisThe presence of periorbital and facial oedema with normal blood pressure in this toddler indicates that he has nephrotic syndrome. Nephrotic syndrome can be associated with a series of complications that can affect an individual’s health and quality of life:Spontaneous bacterial peritonitis can develop where there is ascites present. This is a frequent development in children but very rarely found in adults.Spontaneous bacterial peritonitis (SBP) is the development of a bacterial infection in the peritoneum, despite the absence of an obvious source for the infection. It is specifically an infection of the ascitic fluid -an increased volume of peritoneal fluid. Ascites is most commonly a complication of cirrhosis of the liver. It can also occur in patients with nephrotic syndrome. SBP has a high mortality rate.The diagnosis of SBP requires paracentesis, a sampling of the peritoneal fluid taken from the peritoneal cavity. If the fluid contains large numbers of white blood cells known as neutrophils (>250 cells/µL), infection is confirmed and antibiotics will be given, without waiting for culture results. In addition to antibiotics, infusions of albumin are usually administered.Signs and symptoms of spontaneous bacterial peritonitis (SBP) include fevers, chills, nausea, vomiting, abdominal pain and tenderness, general malaise, altered mental status, and worsening ascites. Thirteen percent of patients have no signs or symptoms. In cases of acute or chronic liver failure SBP is one of the main triggers for hepatic encephalopathy, and where there is no other clear causal indication for this, SBP may be suspected.These symptoms can also be the same for a spontaneous fungal peritonitis (SFP) and therefore make a differentiation difficult. Delay of diagnosis can delay antifungal treatment and lead to a higher mortality rate.

The most probable diagnosis for this patient is bilateral retractile testes. This a normal phenomenon in some pre-pubertal boys. Rationale:Testicular descent can continue until about 3-months of age. The pre-pubertal testis is small enough that with activation of the cremasteric reflex, they can enter the inguinal canal. This in itself is a normal finding providing the testis can be brought into the scrotum without tension and does not require surgical correction. With time the testis will lie within the scrotum. Orchidopexy for true undescended testis can be performed from 6-months of age. It is also warranted if the testes remain undescended or intra-abdominally leading to infertility.Other options:- An ascending testis is one, typically, following hernia or orchidopexy surgery that was in the testis but with time is within the inguinal canal and cannot be brought into the scrotum. Orchidopexy is required for this.- No surgery is required as when the testis enlarges with puberty it will remain within the scrotum.- The testes can be brought into the scrotum. Therefore they are not undescended.- The testes are retractile not ascending; ascending testis cannot be brought into the scrotum and would require orchidopexy.

Bernard- Soulier Syndrome results from a deficiency of platelet glycoprotein protein Ib, which mediates the initial interaction of platelets with the subendothelial components via the von Willebrand protein. It is a rare but severe bleeding disorder. Platelets do not aggregate to ristocetin. The platelet count is low, but, characteristically, the platelets are large, often the size of red blood cells, and may be missed on complete blood counts because most automatic counters do not count them as platelets.

Pierre Robin sequence is a condition present at birth, in which the infant has micrognathia, a tongue that is placed further back than normal (glossoptosis), and cleft palate. This combination of features can lead to difficulty breathing and problems with eating early in life. Pierre Robin sequence may occur isolated or be associated with a variety of other signs and symptoms (described as syndromic). The exact causes of Pierre Robin syndrome are unknown. The most common otic anomaly is otitis media, occurring 80% of the time, followed by auricular anomalies in 75% of cases. Hearing loss, mostly conductive, occurs in 60% of patients, while external auditory canal atresia occurs in only 5% of patients.

Coverings of the spermatic cord:Spermatic cord is covered by three concentric layers of fasciae, derived from the layers the of anterior abdominal wall. Developmentally, each covering is acquired as the processus vaginalis descends into the scrotum through the layers of the abdominal wall. The layers are:External spermatic fascia: It is derived from the external oblique muscle. It attaches to the margins of superficial inguinal ring.Cremasteric fascia: It is derived from the internal oblique muscle. It covers the cremaster muscle.Internal spermatic fascia: It is derived from the fascia transversalis (fascia covering the transversus abdominis muscle). It is attached to the margins of the deep inguinal ring.

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.

Developmental dysplasia (DDH) of the hip refers to patients who are born with a dislocated or unstable hip due to abnormal development of the hip. Female infants and first born infants are most likely to present with DDH. Other risk factors for DDH include, breech positioning, oligohydramnios, high birth weight or post date babies.

Unconjugated bilirubin is conjugated to glucuronic acid in the hepatocyte. Conjugated bilirubin passes into the enterohepatic circulation and the bilirubin which evades this system is metabolised by bacteria, primarily in the large intestine, to urobilinogen, then stercobilinogen and eventually oxidised to stercobilin. Stercobilin gives faeces its brown colour.

Tricuspid atresia is the third most common form of cyanotic congenital heart disease, with a prevalence of 0.3-3.7% in patients with congenital heart disease. The deformity consists of a complete lack of formation of the tricuspid valve with the absence of a direct connection between the right atrium and right ventricle.The following 3 considerations guide the treatment of infants with tricuspid atresia:- The amount of pulmonary blood flow must be regulated to decrease hypoxemia or symptoms of congestive heart failure.- Myocardial function, the integrity of the pulmonary vascular bed, and pulmonary vascular integrity must be preserved to optimize conditions for a later Fontan operation.- The risk of bacterial endocarditis and thromboembolism must be minimized.Infants with decreased pulmonary blood flow: encompasses most of the infants with tricuspid atresia.Marked cyanosis and hypoxemia characterize the clinical course. Acidaemia may occur if the hypoxemia is profound, and death can ensue.Promptly treat infants with severe hypoxemia with prostaglandin E infusions to maintain patency of the ductus arteriosus and improve pulmonary blood flow.Infants with increased pulmonary blood flow: These infants have an associated unrestrictive ventricular septal defect and transposed great vessels.They present with severe congestive heart failure and benefit from digitalis and diuretic therapy until an operative intervention can be undertaken to restrict the pulmonary blood flow.

Laxatives have been shown to be beneficial in the treatment of chronic childhood constipation. Studies have shown that polyethylene glycol, mineral oil, magnesium hydroxide, and lactulose are effective and can be used for a prolonged periods without risk.

Bitemporal hemianopia is a characteristic finding seen in patients with optic chiasm lesion.The pituitary gland is situated within the pituitary fossa. Just above the pituitary fossa is the optic chiasm and so any expanding masses from the pituitary gland commonly press on it, causing bitemporal hemianopia.Other options:- Compression of the optic nerve would not cause more severe, generalised visual loss. Also, the optic nerve is not anatomically related to the pituitary gland and so is unlikely to be directly compressed in the presence of a pituitary tumour.- The optic tract is again not closely anatomically related with the pituitary gland and so is unlikely to be directly compressed in the presence of a pituitary tumour. Also, damage to the optic tract on one side would cause homonymous hemianopia.- The lateral geniculate nucleus is a centre of cells in the thalamus and is unlikely to be compressed by a pituitary tumour. Its function is to convey sensory information from the optic tract to more central parts of the visual pathway.- The Edinger-Westphal nucleus is located at the level of the superior colliculus in the midbrain and so may not be compressed by an enlarging pituitary tumour.Other visual defects:- Left homonymous hemianopia: It is the visual field defect to the left, due to the lesion of the right optic tract.- Homonymous quadrantanopias are seen in parietal (inferior homonymous quadrantopia) and temporal lobe lesions (superior homonymous quadrantopia). Mnemonic: PITS (Parietal-Inferior, Temporal-Superior)A congruous defect means complete or symmetrical visual field loss, and conversely, an incongruous defect is incomplete or asymmetric.Incongruous defects suggest an optic tract lesion, while congruous defects suggest optic radiation or occipital cortex lesion.

Based on the presentation, the patient is probably a case of Crohn’s disease. The first-line treatment of Crohn’s disease is exclusive enteral nutrition.Exclusive enteral nutrition (EEN)This involves drinking a protein-based formula exclusively for 6-8 weeks. It has been shown to have superior mucosal healing when compared with steroids. Furthermore, it is nutritionally advantageous when compared to steroids and does not have the side-effect profile of steroids.Other options:- Intravenous steroids: This is the first-line treatment for ulcerative colitis (UC) or Crohn’s disease if there is rectal disease (which is not the case here). Side-effects include adrenal suppression, behavioural effects, osteopenia and changes in adipose tissue distribution.- Oral steroids: This can be used if EEN is not possible. However, the side-effect profile is less favourable and is not as effective concerning mucosal healing.- Parental nutrition and surgery: They may be occasionally required in severe cases that have failed first-line therapy.

In a child with an age of 12 months – pincer grasp should be well developed. It is essential to have a good grasp of important milestones. Most 12-month-old children will be mobile, by standing holding onto a support, lifting one foot and moving it sideways (‘cruising’ around the furniture). They will demonstrate a neat pincer grasp, e.g. picking up a raisin or piece of paper between the tip of the index finger and the thumb. Words (or meaningful word-like utterances) are produced, but words are not usually chosen and put together deliberately by a child until after the second birthday (typically around the age of 30 months). Word combinations used earlier than this are likely to be an echo of a learnt phrase which may be understood by the child to be one single word even though they are a combination of more than one word (e.g. daddy, home). Building a tower of three cubes and following a one-step command such as ‘take off your socks’, is expected at 18 months.

Transfusion with blood products carries a risk of acute and more chronic adverse reactions. These reactions can either be immune mediated due to a component mismatch, or non immune, underpinned by bacterial or viral contamination. Reactions range from very mild such as urticaria, to life threatening in the case of transfusion-related acute lung injury. In transfusion with packed red blood cells, the most common adverse event is pyrexia, while urticaria is the most common adverse event that follows infusion with FFP.

Pubic lice are commonly referred to as ‘crabs’ because of their short, broad body (about 1 mm), and large front claws. Pubic lice infestation is diagnosed by finding a crabť louse or eggs on hair in the pubic region or, less commonly, elsewhere on the body (eyebrows, eyelashes, beard, moustache, armpit, perianal area, groin, trunk, scalp). Although pubic lice and nits can be large enough to be seen with the naked eye, a magnifying lens may be necessary to find lice or eggs.Pubic lice are transmitted from person to person most-commonly via sexual contact, although fomites (bedding, clothing) may play a minor role in their transmission.

Minimal change glomerulonephritis presents with mild or benign urinalysis findings. However, proteinuria together with the presence of oval fat bodies are typical.Minimal change glomerulonephritis (nephropathy) accounts for most cases of childhood nephrotic syndrome and 20-25% of adult nephrotic syndrome.

The P value is defined as the probability under the assumption of no effect or no difference (null hypothesis), of obtaining a result equal to or more extreme than what was actually observed. The P stands for probability and measures how likely it is that any observed difference between groups is due to chance. Being a probability, P can take any value between 0 and 1. Values close to 0 indicate that the observed difference is unlikely to be due to chance, whereas a P value close to 1 suggests no difference between the groups other than due to chance. Thus, it is common in medical journals to see adjectives such as highly significantť or very significantť after quoting the P value depending on how close to zero the value is.A lower p-value is sometimes interpreted as meaning there is a stronger relationship between two variables. However, statistical significance means that it is unlikely that the null hypothesis is true (less than 5%).To understand the strength of the difference between two groups (control vs. experimental) a researcher needs to calculate the effect size.

This is a case of nephrotic syndrome that can be confirmed by the presence of urinary albumin. It should be further investigated by a tissue sample to confirm the diagnosis.

Infectious mastitis and breast abscesses are predominantly caused by bacteria that colonize the skin. S. aureus is the most common causative agent, followed by coagulase-negative Staphylococci. The majority of S. aureus isolated are now methicillin-resistant S. aureus (MRSA)Some breast infections (and up to 40% of breast abscesses) may be polymicrobial, with the isolation of aerobes (Staphylococcus, Streptococcus, Enterobacteriaceae, Corynebacterium, Escherichia coli, and Pseudomonas) as well as anaerobes (Peptostreptococcus, Propionibacterium, Bacteroides, Lactobacillus, Eubacterium, Clostridium, Fusobacterium, and Veillonella). A study of primary and recurrent breast abscesses showed that smokers were more likely to have anaerobes recovered (isolated in 15% of patients).Unusual breast infections may be the initial presentation of HIV infection. Typhoid is a well-recognized cause of breast abscesses in countries where this disease is prevalent.

When a child with joint problems presents with red-eye, the likelihood of anterior uveitis must be excluded by involving an ophthalmologist in the assessment. This is because uveitis is the most common extra-articular manifestation of juvenile idiopathic arthritis.Other options:- Cataract: It does not give rise to a red-eye, but leukocoria. Often this would have been picked up at an earlier age. – A patient with a corneal foreign body almost would almost invariably give a suspicious history (onset while playing outdoors etc.), as well as have marked symptoms of ocular discomfort (red, watery and painful eyes). – A child with periorbital cellulitis often presents acutely unwell and distressed. – A child with an uncorrected refractive error often complains of being unable to see in class and does not normally present with ocular redness.

The trigeminal nerve is responsible for the sensory innervation of the head, and the muscles of mastication. The nerve is divided into three branches, the ophthalmic nerve (V1) the mandibular nerve (V2) and the maxillary nerve (V3) which all exit the skull through their respective foramina. An easy way to remember these foramina is with the following mnemonic:Standing Room Only, for V1-V3 respectivelyV1- Superior orbital FissureV2- foramen RotundumV3 foramen Ovale

A surgeon will observe the patient and will decide which procedure he needs.

Atopic dermatitis (AD), also called atopic eczema, is a common chronic or recurrent inflammatory skin disease and affects 15-20% of children and 1-3% of adults worldwide. It is characterized by acute flare-ups of eczematous pruritic lesions over dry skin.The incidence has increased by 2- to 3-fold during the past decades in industrialized countries.Some of the most valuable AD prevalence and trend data have come from the International Study of Asthma and Allergies in Childhood (ISAAC). This is the biggest (close to 2 million children in 100 countries) and only allergy study that has taken a truly global approach. The strength of the study is the use of a uniformly validated methodology allowing a direct comparison of results between paediatric populations all over the world (http://isaac.auckland.ac.nz/index.html).

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.

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.

Cystinosis is a condition characterized by accumulation of the amino acid cystine (a building block of proteins) within cells. This condition is inherited in an autosomal recessive pattern.Excess cystine damages cells and often forms crystals that can build up and cause problems in many organs and tissues. The kidneys and eyes are especially vulnerable to damage; the muscles, thyroid, pancreas, and testes may also be affected.There are three distinct types of cystinosis. In order of decreasing severity, they are nephropathic cystinosis, intermediate cystinosis, and non-nephropathic or ocular cystinosis.Nephropathic cystinosis begins in infancy, causing poor growth and a particular type of kidney damage (renal Fanconi syndrome) in which certain molecules that should be reabsorbed into the bloodstream are instead eliminated in the urine. The kidney problems lead to the loss of important minerals, salts, fluids, and many other nutrients. The loss of nutrients impairs growth and may result in soft, bowed bones (hypophosphatemic rickets), especially in the legs. The nutrient imbalances in the body lead to increased urination, thirst, dehydration, and abnormally acidic blood (acidosis). By about the age of 2, cystine crystals may be present in the clear covering of the eye (cornea). The build-up of these crystals in the eye causes pain and an increased sensitivity to light (photophobia). Untreated children will experience complete kidney failure by about the age of 10. Other signs and symptoms that may occur in untreated people, especially after adolescence, include muscle deterioration, blindness, inability to swallow, diabetes, thyroid and nervous system problems, and an inability to father children (infertility) in affected men.The signs and symptoms of intermediate cystinosis are the same as nephropathic cystinosis, but they occur at a later age.

The antiretroviral agent for the side effects mentioned is most probably, efavirenz.Efavirenz is a non-nucleoside reverse transcriptase inhibitor and the most likely cause of new-onset psychiatric symptoms in someone taking HAART. In this scenario the patient had no pre-existing mental health problems, as other antiretrovirals can cause depression and suicidal ideation in those who have a past psychiatric history. Symptoms usually subside after a few weeks of treatment.Other options:- Emtricitabine is a nucleoside reverse transcriptase inhibitor and is also not known to cause psychiatric side effects. The most common side effects of Emtricitabine are rash and darkening of the palms or soles.- Lamivudine is a nucleoside reverse transcriptase inhibitor, which can cause insomnia, but does not commonly cause other psychiatric symptoms.- Rilpivirine is a non-nucleoside reverse transcriptase inhibitor, which can cause depression. However, this is more common in those with a history of mental health problems.- Tenofovir is a nucleotide reverse transcriptase inhibitor. The most common side effect of Tenofovir is gastrointestinal upset. It is not known to cause psychiatric side effects.

Doctors must perform an infection screen and treat with intravenous antibiotics for at least 48 hours pending results to prevent neonatal sepsis. Risk factors for neonatal sepsis include rupture of the membranes. Risk factors for neonatal sepsis include rupture of membranes greater than 12-24 hours, intrapartum maternal pyrexia (> 38°C), fetal tachycardia, chorioamnionitis, pre-term birth and maternal colonisation with group B Streptococcus. In this case there are two risk factors: prolonged rupture of membranes, and pre-term birth.

Scarlet fever is a childhood infectious disease caused by group A Streptococcus. It produces a papular rash, which is classically described as a sand-paper rash. The rash initially appears on the trunk, groin, and underarms and then spreads to extremities, usually sparing the palms and soles. Circumoral area is also spared, giving it pallor-like appearance. Diseases like erythema multiforme, contact dermatitis, staphylococcal scalded skin syndrome, and rubella produce a rash that classically affects the palms and soles.

To get more information regarding hearing loss, a physician should perform both Rinne and Weber tests. Weber test alone cannot tell which side is affected.Rinne test – a vibrating tuning fork (typically 512 Hz) is placed initially on the mastoid process behind each ear until sound is no longer heard. Then, without re-striking the fork, the fork is then quickly placed just outside the ear with the patient asked to report when the sound caused by the vibration is no longer heard. A normal or positive Rinne test is when sound is still heard when the tuning fork is moved to air near the ear (air conduction or AC), indicating that AC is equal or greater than (bone conduction or BC).Weber’s test – tuning fork is placed in the middle of the forehead equidistant from the patient’s ears. The patient is then asked which side is loudest. In unilateral sensorineural deafness, sound is localised to the unaffected side however in unilateral conductive deafness, sound is localised to the affected side.