A case–control study (also known as case–referent study) is a type of observational study in which two existing groups differing in outcome are identified and compared on the basis of some supposed causal attribute. Case–control studies are often used to identify factors that may contribute to a medical condition by comparing subjects who have that condition/disease (the cases) with patients who do not have the condition/disease but are otherwise similar (the controls).
An odds ratio (OR) is a statistic that quantifies the strength of the association between two events, A and B. The odds ratio is defined as the ratio of the odds of A in the presence of B and the odds of A in the absence of B or vice versa.

Although WPW syndrome is a type of supraventricular re-entrant tachycardia, CCBs are contraindicated in its management. This is because CCBs depress AVN conduction| the current then passes through the accessory pathway (bundle of Kent) instead, causing ventricular tachycardia.

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.

The baby may have hydrocephalus and no surgery can be done until it is excluded.Cranial sonography is an important part of neonatal care in general, and high-risk and unstable premature infants, in particular. It allows rapid evaluation of infants in the intensive care units without the need for sedation and with virtually no risk. Expectedly, sonography represents an ideal imaging modality in neonates due to its portability, lower cost, speed, and lack of ionizing radiations. Although there are numerous indications for cranial sonography, it appears to be most useful for detection and follow-up of intracranial haemorrhage, hydrocephalus, and periventricular leukomalacia (PVL).

Koebner’s phenomenon describes skin lesions that occur on damaged skin, usually in a linear fashion at the site of injury. Conditions which exhibit true Koebnerisation include psoriasis, lichen planus, lichen sclerosis, vitiligo, Kaposi sarcoma and SLE. Conditions such as erythema nodosum or multiforme, or Lyme disease and Impetigo do not exhibit Koebner’s phenomenon.

The most probable diagnosis in this patient would be pulmonary stenosis. Pulmonary Stenosis:Pulmonary valve murmurs are heard in the upper left sternal edge, associated with a thrill but no desaturation in the absence of an additional shunt. The ECG changes suggest right ventricular hypertrophy. Pulmonary stenosis is often well tolerated in childhood unless severe. These should be monitored with serial echocardiography, and balloon pulmonary valvoplasty should be considered once the pressure gradient reaches 64 mmHg.Other options:- Atrial septal defect: While atrial septal defects are associated with right ventricular outflow tract murmurs, they would not cause a thrill.- Patent ductus arteriosus: PDA murmurs can be audible in the left upper sternal edge, but would normally be audible in the left infraclavicular area and be continuous rather than ejection systolic. This left to right shunt would not cause desaturation but does cause left-sided volume loading and hence left-sided ECG changes.- Tetralogy of Fallot: Ventricular septal defect, overriding aorta, subpulmonary stenosis, and right ventricular hypertrophy. This would often cause a ULSE murmur with a thrill and RVH on ECG. However, this degree of obstruction would cause shunting from right to left, and this child would be desaturated.- Ventricular septal defect: Isolated ventricular septal defects cause pansystolic murmurs at the left lower sternal edge. They would have left-sided ECG changes and normal saturations (in the absence of pulmonary hypertension).

A consultation with an ENT is required to establish the reason for the child’s drooling and stridor indicating and obstructive process. Enlarged tonsils and adenoids should be checked.

Congenital hypertrophy of the retinal pigment epithelium is one of FAP’s extra-intestinal manifestations. It appears in early childhood and affects an estimated 90% of those with FAP.

Several types of right-sided aortic arch exist, the most common ones being right-sided aortic arch with aberrant left subclavian artery and the mirror-image type. The variant with aberrant left subclavian artery is associated with congenital heart disease in only a small minority of affected people. The mirror-image type of right aortic arch is very strongly associated with congenital heart disease, in most cases tetralogy of Fallot. A right-sided aortic arch does not cause symptoms on itself, and the overwhelming majority of people with the right-sided arch have no other symptoms. However when it is accompanied by other vascular abnormalities, it may form a vascular ring, causing symptoms due to compression of the trachea and/or oesophagus.

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 – feetTinea 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.

In the first trimester of pregnancy, amniotic fluid is produced from maternal plasma where there is a rapid bi-directional diffusion across the foetal skin. At 10 weeks the volume is about 25ml. By 16th weeks of gestation the foetal kidneys make urine that contributes to the increasing volume of amniotic fluid, along with nasal secretions. At 20 weeks, the level is 400ml and increases to 800ml at 28weeks, after which it reduces to 600ml at term.

Among the given options, the inability to grip a sheet of paper between his fingers when the hand is placed flat on the table is the feature of ulnar nerve injury. Rationale:The ulnar nerve (usually) supplies sensation to the skin of the fifth and the ulnar side of the fourth finger, front and back. Following the injury of the nerve, the following functions are impaired:- There is a sympathetic interruption, with the absence of sweating in the affected area. – The thenar muscles are supplied by the median nerve and are therefore spared. – The ulnar nerve also supplies the muscles of the hypothenar eminence. – Although the ring and little fingers are held in the clawed position when the nerve is injured at the wrist, a high lesion paralyses the long flexors to these two fingers and results in the loss of this sign. The test for paralysis of the palmar interossei, supplied by the ulnar nerve, is the inability to adduct the fingers and thus to be unable to grip a sheet of paper between them.

To prevent mother to child transmission in the case of an HIV infected mother, guidelines have been put in place in the that guide practices. During pregnancy the risk of intrauterine transmission is quite low, as is the risk of transmission during vaginal delivery. As a result the number of women that choose to have caesarean sections have fallen, with vaginal births increasing by 40%. One factor that can however increase the risk of mother to child HIV transmission is concurrent Hepatitis C infection which double the risk of vertical transmission.

Internal abdominal bleeding is most probably the cause of the child’s shock, especially unresponsive to fluid boluses.

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

Germinal matrix/intraventricular haemorrhage (GM/IVH) is a complication of premature delivery that can result in life-long medical and developmental consequences. Although GM/IVH can occur in term infants, haemorrhage in this group of infants remains distinct from periventricular haemorrhage (PVH)/IVH of the preterm infant. Several acquired lesions of the central nervous system (CNS) specifically affect infants born prematurely and result in long-term disability, including GM/IVH, periventricular white matter injury (e.g., cystic periventricular leukomalacia [CPVL], periventricular haemorrhagic infarction [PVHI]), haemorrhage, and diffuse injury to the developing brain.The physical examination is usually negative in germinal matrix/intraventricular haemorrhage (GM/IVH). Occasionally, severe GM/IVH may present with nonspecific systemic findings suggestive of cardiovascular collapse.One subgroup of infants with GM/IVH presents with the following:- A sudden unexplained drop in haematocrit levels- Possible physical findings related to anaemia (e.g., pallor, poor perfusion) or haemorrhagic shockAnother subgroup of infants with GM/IVH presents with extreme signs, including the following:- A sudden and significant clinical deterioration associated with anaemia, metabolic acidosis, glucose instability, respiratory acidosis, apnoea, hypotonia, and stupor is present.Physical findings related to these signs include poor perfusion, pallor or an ashen colour, irregularities of respiratory pattern, signs of respiratory distress including retractions and tachypnoea, hypotonia, and altered mental status (e.g., decreased responsiveness, coma).Additional neurologic signs, such as fullness of the fontanelles, seizures, and posturing, may also be observed. Progression can be rapid and may result in shock and death.Extradural haemorrhage also known as an epidural hematoma, is a collection of blood that forms between the inner surface of the skull and outer layer of the dura, which is called the endosteal layer. They are usually associated with a history of head trauma and frequently associated skull fracture. The source of bleeding is usually arterial, most commonly from a torn middle meningeal artery.A subdural haemorrhage (or hematoma) is a type of bleeding that often occurs outside the brain as a result of a severe head injury. It takes place when blood vessels burst between the brain and the leather-like membrane that wraps around the brain (the dura mater). The pooling blood creates pressure on the surface of the brain, causing a variety of problems.

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 shows features of neurofibromatosis. The most likely cause for hypertension in this patient would be renal artery stenosis.Note:Neurofibromatosis is an inherited autosomal dominant disorder which could have affected this girl’s father, and she appears to have the classic skin lesions. A renal bruit might be heard in these patients. Polycystic kidney disease can occur in association with tuberous sclerosis, which also has skin lesions associated (different from those described in this patient). Most causes of hypertension in childhood have underlying renal causes, and a renal ultrasound with doppler is the first-line investigation of choice. Even if this is normal, further imaging would be indicated here, for example, isotope renal scans and angiography.

Answer: Do not operate and review the patient several weeks laterAir weapon injuries in children should be managed in the same way as any low velocity gun shot injury. Subcutaneous pellets are best removed. Urgent specialist referral is indicated for cranial, ocular, chest, abdominal, or vascular injuries as they may require emergency surgery. Cardiac injuries may be rapidly fatal. Penetrating abdominal injuries involving hollow viscera or major blood vessels need prompt exploration and repair. Intracranial air weapon pellets should be removed if possible. A pellet in lung parenchyma or muscle may be safely left in situ but there is a risk of infection. A pellet that has penetrated a joint or is associated with a fracture requires skilled orthopaedic management. A pellet lodged near a major blood vessel or nerve should ideally be removed. The possibility of intravascular embolism must be considered if the pellet is absent from a suspected entry site and there is no exit wound| numerous examples of arterial and venous embolism of an air weapon pellet in children have been described.In this case, the child seems well so there is no need to operate. He should be reviewed several weeks later.

Haemolytic Uremic Syndrome affects children and is characterised by abdominal pain, a purpuric rash over the body, generalized pallor, haematuria and bloody diarrhoea. There is always a history of preceding diarrhoea caused usually by E.coli and it affects the renal system causing haematuria and deranged renal function tests.

Autism is a neurodevelopmental disorder characterized by difficulties with social interaction, language delays, and some repetitive behaviours. Autism may be associated with some dysmorphic facial features, including macrocephaly, which denotes an abnormally large head. Macrocephaly is usually most observable during early childhood. The other features mentioned are not found to be associated with autism.

In the pattern of mendelian inheritance, X- linked dominant inheritance means that all who inherit the X chromosome will present with the condition. In the case of maternal x-linked inheritance sons and daughters have an equal chance of inheriting the condition as there is a 50% chance of inheriting the defective X chromosome from their mother as opposed to a non affected X chromosome from their father. However in paternal X-linked dominant inheritance, sons will be unaffected as they inherit a Y chromosome from their father while daughters are sure to inherit the defective X-chromosome.

Blalock-Thomas-Taussig shunt is a surgical procedure done to increase pulmonary blood flow in cases like pulmonary atresia and results in a continuous murmur.The type of murmur which is heard during the systole and remains continuous till the second heart sound is known as a continuous murmur. This murmur is often intense and considered rough. It can also be accompanied by quivering. There are numerous causes of a continuous murmur that differ depending on the location and components of this murmur. It is caused by the shunting of blood from a high-pressure circulation to a low-pressure circulation. Pathological causes of a continuous murmur include patent ductus arteriosus, aortopulmonary window, AV malformation, coarctation of aorta, any acquired trauma, and iatrogenic cause like interventional or surgical procedures.

The trigeminal nerve is responsible for the motor innervation of the muscles of mastication and well as providing sensory input for most of the head. In testing the function of this nerve, the jaw jerk reflex may be brisk in cases of upper motor neuron lesions, but is however absent in nuclear or infra nuclear lesions involving the trigeminal nerve. Other nerve reflexes include the gag reflex of the glossopharyngeal nerve, and the pupillary light reflex of the optic nerve.

The most probable diagnosis based on the clinical presentation is myocarditis secondary to Coxsackie virus infection.Myocarditis is an important cause of acquired heart failure. The other infective causes of myocarditis are influenza and adenoviruses, and bacterial causes as seen with Borrelia burgdorferi (Lyme disease). Rheumatic fever is unlikely if the ASO titres are within normal limits. While pancarditis may occur as part of Kawasaki disease| the patient is unlikely to present in failure.

E. coli accounts for the majority of UTI’s in children. If this child responds well to treatment and has no recurrence of his symptoms, then no form of imaging is required, as per NICE advice for children aged 6 months to 3 years. Had the child been less than 6 months of age, then a USS at 6 weeks would be necessary.Other options:- Pseudomonas causes atypical UTI. This warrants ultrasonography within the acute illness phase as it may reflect an underlying pathology and DMSA at 4-6 months.- Recurrent UTI is defined as two or more episodes of pyelonephritis OR 1 pyelonephritis and one cystitis OR 3 or more cystitis. It requires USS at six weeks and DMSA at 4-6 months.- Septicaemia is a sign of an atypical UTI. This requires USS within the acute illness as it may reflect an underlying pathology and DMSA at 4-6 months.- Unwell 48hrs post antibiotics is a sign of an atypical UTI. This requires USS within the acute illness as may reflect underlying pathology and DMSA at 4-6 months.

A supracondylar humerus fracture is a fracture of the distal humerus just above the elbow joint. The fracture is usually transverse or oblique and above the medial and lateral condyles and epicondyles. This fracture pattern is relatively rare in adults, but is the most common type of elbow fracture in children. They are historically associated with morbidity due to malunion, neurovascular complications, and compartment syndrome. Important arteries and nerves ( median nerve, radial nerve, brachial artery, and ulnar nerve) are located at the supracondylar area and can give rise to complications if these structures are injured. Most vulnerable structure to get damaged is Median Nerve. Damage/occlusion of the brachial artery is the cause of an absent radial pulse.

A lucid interval, in which the patient portrays a temporary improvement in condition after a traumatic brain injury, is especially indicative of an epidural haematoma.

People with Systemic Juvenile Idiopathic Arthritis (also known as Stills disease) can have recurrent fevers, a macular rash, joint pain, joint deformities, an enlarged liver and/or spleen, and can occasionally have polyserositis, lung involvement or pericardial effusions. Rheumatoid factor and antinuclear antibodies are usually negative. Treatment is with non-steroidal anti-inflammatory drugs (NSAIDs) and the prognosis is better than for adult rheumatoid arthritis.In pauciarticular Still’s disease, antinuclear antibodies are present. Large joints are affected and most patients develop classic features of seronegative spondylarthritis.

The lateral spinothalamic tracts carry pain and temperature sensations from the peripheries to the central nervous system.Note:The spinothalamic tract transmits impulses from receptors which measure crude touch, pain and temperature. The spinothalamic tract comprises the lateral and anterior spinothalamic tracts.The former typically transmits pain and temperature while the latter transmits crude touch and pressure. Neurones transmitting these signals will usually ascend by one or two vertebral levels in the Lissauer tract before decussating in the spinal cord itself. Neurones then pass rostrally in the cord to connect at the thalamus.