Congenital adrenal hyperplasia is a common cause of virilisation in females that can present as ambiguous genitalia at birth. Deficiency of the 21-alphahydroxylase enzyme is implicated in excess mineralocorticoid and androgens produced by the adrenal gland. Virilisation occurs when excess androgens are converted to testosterone in a genetically female foetus, causing the genitalia to resemble male genitalia. A deficiency of 5-alpha hydroxylase would rather decrease the production of testosterone and lead to the presentation of external female genitalia in a genetically male foetus. Autoantibodies against glutamic acid are seen in type 1 diabetes mellitus, while defects in the AIRE gene and the FOXP3 affect components of the immune system.

Retinopathy of prematurity (ROP) affects premature infants. It is a retinal vasoproliferative disease for which current screening guidelines are primarily based on birth weight and gestational age. The disease is first detected by screening at 32-38 weeks of gestation or in infants that are about 6-7 weeks old. Screening consists of dilation of the pupils and observing for dilated vessel.

From the given scenario, the extraocular muscle affected in the child is superior oblique muscle. Point to remember:All of the extraocular muscles are supplied by the oculomotor nerve (3rd cranial nerve), except superior oblique (trochlear nerve/4th cranial nerve) and lateral rectus (abducens nerve/6th cranial nerve).The superior oblique muscle causes the eye to move downwards and medially. The unopposed inferior oblique, in this case, causes the eye to deviate upwards and medially. Children tend to tilt their head (torticollis) to the side opposite to the affected eye with their chin down toward the shoulder, and their face turned away from the affected side to decrease the diplopia.

Fanconi tubular syndrome is characterised by malabsorption of various electrolytes and substances commonly absorbed by the proximal tubule. Hypokalaemia, hypophosphatemia, and hyperchloremic metabolic acidosis is usually present. Also, urinalysis reveals an increased fractional excretion of glucose.

Infective endocarditis (IE) is defined as an infection of the endocardial surface of the heart.Fever, possibly low-grade and intermittent, is present in 90% of patients with IE. Heart murmurs are heard in approximately 85% of patients.One or more classic signs of IE are found in as many as 50% of patients. They include the following:- Petechiae: Common, but nonspecific, finding- Subungual (splinter) haemorrhages: Dark-red, linear lesions in the nail beds -Osler nodes: Tender subcutaneous nodules usually found on the distal pads of the digits- Janeway lesions: Nontender maculae on the palms and soles- Roth spots: Retinal haemorrhages with small, clear centres| rareSigns of neurologic disease, which occur in as many as 40% of patients, include the following:- Embolic stroke with focal neurologic deficits: The most common neurologic sign- Intracerebral haemorrhage- Multiple microabscessesOther signs of IE include the following:- Splenomegaly- Stiff neck- Delirium- Paralysis, hemiparesis, aphasia- Conjunctival haemorrhage- Pallor- Gallops- Rales- Cardiac arrhythmia- Pericardial rub- Pleural friction rub

Synchronized IMV (SIMV) with pressure support, used in the alert infant. SIMV guarantees a minimum minute volume while allowing the patient to trigger spontaneousbreaths at a rate and volume determined by the patient. Extra breaths are boosted with pressure support. Tidal Volume (Vt) is normally approximately 6-10 mL/kg and 4-6 ml/kg in the preterm.Respiratory rate (RR) is usually 30-60 BPM. Tidal volume and respiratory rate are relatedto respiratory minute volume as follows: Vm(mL/min) = Vt x RR .This baby is overventilated with a low CO2. Tidal volumes should generally be targeted at 4–6 ml/kg and this baby is being targeted at 9 ml/kg which exposes the baby to damage to the distal airways from this ventilation which can lead to bronchopulmonary dysplasia.

The adult height potential may be calculated for a male child by (father’s height in cm + mother’s height in cm) / 2 then add 7 cm.In the scenario provided: (170 + 150)/2 + 7 = 167 cm = 1.67 m.For a female child by (father’s height in cm + mother’s height in cm) / 2 then minus 7 cm.This can then be plotted on a height centile chart to find the mid-parental centile.Causes of short stature include:- Normal variant (often familial)- Constitutional delay of growth and puberty- Chronic illness, e.g. cystic fibrosis, inflammatory bowel disease- Endocrine: growth hormone deficiency, hypothyroidism, steroid excess syndromes: Turner’s, Down’s, Prader-Willi- Skeletal dysplasias, e.g. achondroplasia

The submandibular glands provide the bulk of salivary secretions contributing close to 70%. The sublingual glands provide 5% and the remainder from the parotid.

Jaundice in a new-born on the day of delivery is most likely due to Rh incompatibility. This occurs when the mother is Rh-negative and the baby is Rh-positive. Antibodies in the mother against the Rh factor in the baby will destroy the red blood cells in the baby, increasing the bilirubin in the blood. Breast milk jaundice and Galactosemia do not occur immediately after birth, and congenital rubella syndrome and formula feeding does not cause jaundice in babies.

Compared to parametric tests, non parametric tests are seen to be less powerful as they often contend with fewer assumptions, and may use less information from the data. Sample sizes can be smaller. The samples do not have to follow a normal distribution as in parametric tests, and data may be ordinal, ranked or contain outliers that cannot be removed. Therefore nonparametric tests are well suited for these instances and do not need to be used as a last resort. They are not any more complex than parametric tests.

Based on the clinical presentation, the child probably has orthostatic proteinuria.Orthostatic proteinuria occurs when the kidneys can conserve urine when the patient is recumbent, such as sleeping at night, but leak protein with standing or in exercise. This results in early morning urine being negative for protein but late in the day urine being positive. It is mostly seen in tall thin adolescents and is benign. Other options:- Alport’s syndrome is a hereditary condition associated with haematuria and deafness. – Urinary tract infections can cause proteinuria, but leucocyte esterase and nitrites would also be expected in a child of this age. – Nephritic syndrome can be associated with proteinuria, but haematuria would also be present. – In nephrotic syndrome, proteinuria would be present on all occasions and associated with oedema.

Upper brachial plexus roots innervate the proximal muscles of the shoulder and the upper arm. In this particular case, only these areas are affected, suggesting that the levels of brachial plexus injury are at roots C5-C6.

The clinical picture suggests a vitamin K deficiency haemorrhagic disease of the new-born and requires IV vitamin K and fresh frozen plasma. This usually presents with gastrointestinal bleeding, bleeding from the umbilical stump and bruising after 2–7 days.

Narcolepsy is a rare condition characterised by excessive daytime sleepiness, sleep paralysis, hypnagogic hallucinations, and cataplexy (sudden collapse triggered by emotion such as laughing or crying). There is no cure for narcolepsy. Treatment options include stimulants, such as methylphenidate (Ritalin) or modafinil (Provigil), antidepressants, such as fluoxetine (Prozac), citalopram (Celexa), paroxetine (Paxil), sertraline (Zoloft) and sodium oxybate (Xyrem). Modafinil has replaced methylphenidate and amphetamine as the first-line treatment of excessive daytime sleepiness (EDS).

Adenoid tissue sometimes swell as a result of fighting off the infection as germs are trapped in the adenoids. Adenoid enlargement is suspected.

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.

Miliaria is a common skin disease caused by blockage and/or inflammation of eccrine sweat ducts. Miliaria is frequently seen in hot, humid or tropical climates, in patients in the hospital, and in the neonatal period. Miliaria is also known as sweat rash.Based on the level of the sweat duct obstruction, miliaria is divided into three subtypes:- Miliaria crystallina (sudamina), caused by obstruction of the sweat ducts close to the surface of the skin (epidermis)|- Miliaria rubra, caused by obstruction of the sweat ducts deeper in the epidermis|- Miliaria profunda (tropical anhidrosis), the result of sweat leaking into the middle layer of skin (dermis).Miliaria crystallina appears as 1–2 mm superficial clear blisters that easily break. The blisters can look like beads of sweat. There is no inflammation. The blisters are usually seen widely spread on the head, neck, and upper trunk.Miliaria rubra is the most common type of miliaria results in red, 2–4 mm, non-follicular papules and papulovesicles. They are very itchy. Background erythema is often present. In children, miliaria affects the skin folds of the neck, axilla or groin. In adults, miliaria often affects the upper trunk, scalp, neck and flexures, particularly areas of friction with clothing. Miliaria pustulosa is a variant of milia rubra in which there are pustules.Miliaria profunda describes asymptomatic deep papules. The flesh–coloured, 1–3 mm diameter papules usually arise on the trunk and extremities.Mild Topical steroids can be used as a treatment

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

Chédiak–Higashi syndrome is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

Meckel’s diverticulum is a congenital diverticulum of the small intestine. It is a remnant of the omphalomesenteric duct (also called the vitellointestinal duct) and contains ectopic ileal, gastric or pancreatic mucosa.Rule of 2’s- occurs in 2% of the population- it is located 2 feet proximal to the ileocaecal valve- it is 2 inches long- it is 2 times more common in men- there are 2 tissue types involvedIt is typically asymptomatic. Symptomatic presentation indicates inflammation of the diverticulum. The symptoms include:- Abdominal pain mimicking appendicitis- Rectal bleeding- Intestinal obstruction: secondary to an omphalomesenteric band (most commonly), volvulus and intussusceptionManagement:Surgical removal if the neck of the diverticulum is narrow or symptomatic. Surgical options are excision or formal small bowel resection and anastomosis.

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.

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.

Gitelman syndrome is a kidney disorder that causes an imbalance of charged atoms (ions) in the body, including ions of potassium, magnesium, and calcium.The signs and symptoms of Gitelman syndrome usually appear in late childhood or adolescence. Common features of this condition include painful muscle spasms (tetany), muscle weakness or cramping, dizziness, and salt craving. Also common is a tingling or prickly sensation in the skin (paraesthesia), most often affecting the face. Some individuals with Gitelman syndrome experience excessive tiredness (fatigue), low blood pressure, and a painful joint condition called chondrocalcinosis. Studies suggest that Gitelman syndrome may also increase the risk of a potentially dangerous abnormal heart rhythm called ventricular arrhythmia.

Unless given IV, a drug must cross several semipermeable cell membranes before it reaches the systemic circulation. Drugs may cross cell membranes by diffusion, amongst other mechanisms. The rate of diffusion of a substance is proportional to the difference in the concentration of the diffusing substance between the two sides of the membrane, the temperature of the solution, the permeability of the membrane and, in the case of ions, the electrical potential difference between the two sides of the membrane.

The risk of ischemic stroke in patients using combined oral contraceptives is increased in patients with additional stroke risk factors, including smoking, hypertension, and migraine with aura.

Congenital hypothyroidism (CH) is inadequate thyroid hormone production in new-born infants. It can occur because of an anatomic defect in the gland, an inborn error of thyroid metabolism, or iodine deficiency.CH is the most common neonatal endocrine disorder, and historically, thyroid dysgenesis was thought to account for approximately 80% of cases. However, studies have reported a change in the epidemiology, with a doubling in incidence to around 1 in 1500 live new-borns.​Infants with congenital hypothyroidism are usually born at term or after term. Symptoms and signs include the following:Decreased activityLarge anterior fontanellePoor feeding and weight gainSmall stature or poor growthJaundiceDecreased stooling or constipationHypotoniaHoarse cryProlonged neonatal jaundice or unconjugated hyperbilirubinemia

At least seven episodes in the previous year, five episodes in each of the previous two years, or three episodes in each of the previous three years are indications for tonsillectomy. Antibiotics should be administered in the conventional dosage for proved or suspected streptococcal episodes. For now the child should be treated on a case by case basis.

Neurofibromatosis type 1 (NF1) is a common autosomal dominant disease. The Lisch nodule represents one of the most common NF1 ocular manifestations.NF1 is caused by a genetic mutation which can cause tumours to grow on nerve endings| these cutaneous neurofibromas are benign tumours which grow on the skin, often first appearing during the hormonal changes that occur in teenage years. They vary in size and can appear anywhere on the body. The number of neurofibromas present differs greatly between individuals and over a lifetime Café au lait spots (coffee coloured birthmarks) are often the first and most common sign of NF1, and these are often found at birth and are usually evident by 2 years of age.Other features of NF1 can include Lisch nodules of the iris (small pigmentation in the iris which causes no disturbance to vision), skin-fold freckling (freckling/pigmentation in the groyne and armpits), plexiform neurofibromas (or sub cutaneous neurofibromas) which are diffuse tumours that grow along a nerve and are found in at least 25 % of people with NF1, optic gliomas (tumour of the optic nerve), and skeletal complications including pseudarthrosis and scoliosis. Macrocephaly (large head size) is also common, and short stature is found in around a third of people with NF1. Rare complications include a risk of malignancy, organs being compromised by neurofibromas, seizures, and hypertension.

The most probable diagnosis for the patient in question is atrioventricular nodal re-entrant tachycardia (AVNRT).The presenting features of the patient are suggestive of supraventricular tachycardia (SVT). The most common form of SVT in children over 8 years old is atrioventricular nodal re-entrant tachycardia. It occurs as a result of an additional electrical circuit in or near the AV node itself.Other options:- Atrial Flutter: is a form of re-entry tachycardia within the atria which then becomes unsynchronised with the ventricles, which is not the case here. Furthermore, it is most common in babies and children with congenital heart disease.- Atrial tachycardia: is a condition where an area of atrium takes over the pacemaker activity of the heart. However, it is relatively uncommon.- Atrioventricular re-entrant tachycardia (AVRT): occurs due to an accessory electrical pathway between the atria and ventricles forming a re-entry circuit. This is the most common cause of SVT in children < 8 years old. One of the specific diagnoses of AVRT is Wolff-Parkinson-White syndrome. However, WPW syndrome is much rarer than AVNRT.- Premature atrial contractions (PACs): are very common in normal, healthy children and adolescents. Occasionally, they can give rise to the feeling of a 'skipped beat'. Fortunately, they are rarely associated with any significant underlying pathology or need to be treated.

Factors V and VIII are consumed most rapidly in a patient with disseminated intravascular coagulation.Simultaneous coagulation and haemorrhage caused by initially formation of thrombi which consume clotting factors (factors 5,8) and platelets, ultimately leading to bleeding.Causes include:- Infection- Malignancy- Trauma e.g. major surgery, burns, shock, dissecting aortic aneurysm- Liver disease- Obstetric complicationsClinically bleeding is usually a dominant feature, bruising, ischaemia and organ failure.Blood tests reveal prolonged clotting times, thrombocytopenia, decreased fibrinogen and increased fibrinogen degradation products.Treatment of DIC involves treating the underlying cause and supportive management.Mnemonic:D-I-S-S-E-M-I-N-A-T-E-DD- D dimerI-Immune complexesS-Snakebite, shock, heatstrokeS-SLEE-Eclampsia, HELLP syndromeM-Massive tissue damageI-Infections: viral and bacterialN-NeoplasmsA-Acute promyelocytic leukaemiaT-Tumour products: Tissue Factor (TF) and TF-like factors released by carcinomas of pancreas, prostate, lung,colon, stomachE-Endotoxins (bacterial)D-Dead foetus (retained)