Osteochondromas, or osteocartilaginous exostoses, are the most common benign bone tumours, and tend to appear near the ends of long bones. The overgrowth can occur in any bone where cartilage forms bone, and they are capped by cartilage. They are most common in people between the ages of 10-20 years old.

Café-au-lait spots is hyperpigmented lesions that vary in colour from light brown to dark brown, with borders that may be smooth or irregular. Causes include:
Neurofibromatosis type I
McCune–Albright syndrome
Legius syndrome
Tuberous sclerosis
Fanconi anaemia
Idiopathic
Ataxia-telangiectasia
Basal cell nevus syndrome
Benign congenital skin lesion
Bloom syndrome
Chediak-Higashi syndrome
Congenital nevus
Gaucher disease
Hunter syndrome
Maffucci syndrome
Multiple mucosal neuroma syndrome
Noonan syndrome
Pulmonary Stenosis
Silver–Russell syndrome
Watson syndrome
Wiskott–Aldrich syndrome

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.

The first sign of pubarche in females is breast-bud development (thelarche).This begins between the ages of 9 and 12 years and continues to 12–18 years. Pubic hair growth occurs next (said to occur in stage 3), at ages 9–14 years, and is complete at 12–16 years. Menarche occurs relatively late in stage 4 (age 11–15 years) and is associated with a deceleration in growth. The peak height velocity is reached earlier (10–13 years) and growth is completed much earlier than in boys.

While the clinical scenario and the anosmic presentation of the child are highly suggestive of Kallmann’s syndrome, reduced testosterone, FSH and LH levels can confirm the diagnosis.Kallman’s syndrome is a recognised cause of delayed puberty secondary to hypogonadotropic hypogonadism. It is usually inherited as an X-linked recessive trait. Kallman’s syndrome is thought to be caused by a failure of GnRH-secreting neurons to migrate to the hypothalamus.Clinical features of Kallmann’s syndrome include:- Delayed puberty- Hypogonadism, cryptorchidism- Anosmia- Low sex hormone levels – Inappropriately low/normal LH and FSH levels- Some patients can present with associated cleft lip/palate and visual/hearing defects.

The endocardial cushions in the heart are the mesenchymal tissue that make up the part of the atrioventricular valves, atrial septum and ventricular septum. An incomplete fusion of these mesenchymal cells can cause an atrioventricular septal defect. The terms endocardial cushion defect, atrioventricular septal defect and common atrioventricular canal defect can be used interchangeably with one another.

The most probable cause for the patient’s presenting symptoms is Sarcoptes scabeii.Scabies:The boy in the scenario presents with a pruritic rash affecting the palms of the hands, especially in the web spaces between the fingers. Additionally, the fact that his sister is showing similar symptoms is an indication of its infectivity. The female Sarcoptes scabiei var hominis mite burrows into the webs of fingers and the sides of digits as seen in the child.This parasitic skin infestation presents typically with nocturnal itching. Other options:- Herpes simplex virus type 1 (HSV-1): This can affect this age group but would usually present with a vesicular perioral rash with associated erythema. – Human papillomavirus (HPV): Cutaneous human papillomavirus infection causes warts, which can form a dome and fleshy shaped lesions on the palms of the hands, but these are not usually itchy. Similar to the causative agent in the boy, they are contagious.- Poxvirus: These viruses cause molluscum contagiosum which presents as dome-shaped lesions anywhere on the body, rather than specifically in palms of hands or finger webs as seen in the boy. Poxviruses are also very infectious.- Staphylococcal infection: This causes impetigo, which presents with yellow discharge and underlying erythema. Impetigo is not usually itchy and can present on any part of the body, rather than the specific areas seen in the boy.

Neurofibromatosis is a genetic disease caused by the mutation of the neurofibromin gene on Chromosome 17. The diagnostic criteria for Neurofibromatosis type 1 are two or more of the following:-6 or more cafe au lait macules-2 or more cutaneous neurofibroma or one plexiform Neurofibroma-Axillary of groin freckling -Optic pathway glioma -2 or more Lisch nodules (hamartomas of the iris seen on slit lamp examination)-Bony dysplasia (such as sphenoid wing dysplasia, bowing of the long bones, or pseudarthrosis)-First degree relative with neurofibromatosis type 1

Alopecia is a scalp condition characterized by either overall baldness or patches of hair loss over the head. It can be broadly classified as scarring alopecia and non-scarring alopecia. Non-scarring is the most common type and is seen in various conditions like nutritional deficiencies, alopecia areata, hypothyroidism, tinea capitis, and SLE. Scarring alopecia is commonly seen in cases of discoid lupus erythematosus, which is a common cause of widespread inflammatory and scarring lesions all over the body and scalp.

The presenting features with the positive pregnancy test are highly suggestive of gestational diabetes mellitus.Diabetes Insipidus:It is much less common than gestational diabetes mellitus. It is characterised by the inability to concentrate urine, with marked thirst.Presenting symptoms include polydipsia (>3L daily), polyuria, nocturia, nocturnal enuresis.Physical examination may reveal features of dehydration and an enlarged bladder.Investigations include biochemical analysis for electrolytes, urine and plasma osmolality, fluid deprivation test, and cranial MRI.The main differential diagnosis is for diabetes insipidus is psychogenic polydipsia.There are three broad categories of diabetes insipidus (DI): – Central (cranial) DI: It is the most common form of diabetes insipidus.It occurs due to decreased secretion of ADH. It usually occurs due to hypothalamic disease and may show response to low-dose desmopressin.- Peripheral (nephrogenic) DI:It is characterised by the resistance of the kidney to ADH.It usually does not respond to low-dose desmopressin.- Gestational DI:It is rare and is mostly seen in teenage pregnancy.It usually presents in the third trimester and often resolves 4-6 weeks post-partum.

Based on the clinical scenario provided, the most probable diagnosis is Peutz-Jeghers syndrome.Peutz-Jeghers syndrome is an autosomal dominant condition characterised by numerous hamartomatous polyps in the gastrointestinal tract. It is also associated with pigmented freckles on the lips, face, palms and soles.Genetic basis: It follows an autosomal dominant inheritance, and the gene responsible encodes serine-threonine kinase LKB1 or STK11.Classical features of PJS include:- Hamartomatous polyps in the GI tract (mainly small bowel)- Pigmented lesions on lips, oral mucosa, face, palms and soles- Intestinal obstruction, e.g. intussusception- Gastrointestinal bleedingThe treatment is mainly conservative unless complications develop.Note:Hereditary haemorrhagic telangiectasia can also be associated with mucocutaneous lesions and iron-deficiency anaemia, but intestinal polyps are not a feature.

The paired sample t-test, sometimes called the dependent sample t-test, is a statistical procedure used to determine whether the mean difference between two sets of observations is zero. In a paired sample t-test, each subject or entity is measured twice, resulting in pairs of observations. Common applications of the paired sample t-test include case-control studies or repeated-measures designs.Statistical significance is determined by looking at the p-value. The p-value gives the probability of observing the test results under the null hypothesis. The lower the p-value, the lower the probability of obtaining a result like the one that was observed if the null hypothesis was true. Thus, a low p-value indicates decreased support for the null hypothesis. However, the possibility that the null hypothesis is true and that we simply obtained a very rare result can never be ruled out completely. The cut-off value for determining statistical significance is ultimately decided on by the researcher, but usually a value of .05 or less is chosen. This corresponds to a 5% (or less) chance of obtaining a result like the one that was observed if the null hypothesis was true.

Among the options provided, the most characteristic finding that can be expected in his patient’s urine microscopy is RBC casts. Red cell casts are a characteristic feature of acute nephrotic syndrome. Other options:- Hyaline casts may be seen in normal urine, particularly after exercise. – Coarse granular casts occur in glomerular and tubular disease. – Tubular cell casts may be seen in patients with acute tubular necrosis. – The presence of 10 or more white blood cells/mm3 is abnormal and indicates an inflammatory reaction, most commonly due to infection.

One-third of patients with Guillain-Barre syndrome suffer from diaphragm weakness which can lead to further respiratory complications if there is involvement of the tongue, palate, and neck muscles. Forced vital capacity (FVC) is the best way to monitor respiratory muscle function by assessing it repeatedly. Admission for ITU is suggested when FVC is below 20ml/kg and intubation recommended when FVC is 15ml/kg or below. FVC is used in any neurological disorders wherein the respiratory muscles are affected.

Eczema herpeticum (also called Kaposi varicelliform eruption) is a disseminated viral illness usually associated with lymphadenopathy.It is most often caused by Herpes Simplex type 1 or type 2. Occasionally, other viruses such as coxsackievirus A16 may cause eczema herpeticum. Affected children usually develop itchy blisters and fever after coming in contact with an affected individual who may or may not display cold sores.It is characterised by an itchy and sometimes painful cluster of blisters most commonly on the face initially. This spreads over one to several weeks resulting in further crops of blisters which can become confluent. Lymphadenopathy and fever are common in these patients.The severity varies from mild illness to life-threatening, especially in immunocompromised children or young infants. It is markedly more common in children with atopic dermatitis. It is one of the few dermatological emergencies, and oral antivirals are often indicated. Referral to an ophthalmologist may be needed if there is eyelid or eye involvement. Occasionally, superadded skin infections caused by staphylococci and streptococci can occur.

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.

An important predictor of the foetal well-being is the evaluation of amniotic fluid volumes, commonly done using ultrasonography. Amniotic fluid index (AFI) is calculated by measuring the largest vertical diameter of the fluid pocket in all four quadrants of the uterine cavity and then added together. Oligohydramnios or decreased amniotic fluid volume can be defined as an AFI less than 5cm and occurs in about 4-5% of the pregnancies. It is associated with a number of foetal abnormalities and complications. Foetal abnormalities that lead to oligohydramnios include: premature rupture of membranes, intrauterine growth retardation, and congenital foetal abnormalities among others. A single umbilical artery is an anatomical defect of the umbilical cord, which leads to IUGR, uteroplacental insufficiency and may be associated with multiple congenital abnormalities as well, which all ultimately lead to the development of oligohydramnios. Foetal hydrops, developmental dysplasia of the hip and, macrosomia lead to polyhydramnios. Cleft palate is not associated with any of them.

This temperature is considered to be a mild fever and is most often caused by a minor infection in children of this age. Therefore, an infection screen should be conducted and an IV antibiotic.

The boy suffers from balanitis xerotica obliterans (BXO) which is surgically treated with circumcision and urethral calibration. In fact, the condition is the only true medical indication for circumcision.

Tanner stage two presents with the following: Downy hair, Breast bud palpable under areola (1st pubertal sign in females).Stage 1 (prepubertal) – elevation of papilla only – no pubic hairStage 2 – breast bud forms – sparse, slightly pigmented hair on labia majoraStage 3 – Breast begins to become elevated, extends beyond areola borders – hair becomes more coarse and curlyStage 4 – increased size and elevation. Areola and papilla form secondary mound – adult like, but sparing medial thighsStage 5 – final size, areola returns but papilla remains projected – hair extends to medial thighs

The Chi squared test is used to find the relationship between two variables, determining whether they are not independent of each other. This test of statistical significance allows you to determine the degree of confidence with which you can accept or reject the null hypothesis. The student t test compares the significant differences in data means, while rank correlation, linear regression and the correlation coefficient all help to measure the linear relationship between variables.

Gastrointestinal polyps are common in children and may result in intussusception due to polyp traction. Treatment is usually surgical with enterotomy and removal of the polyp or of a segment of the bowel.

Most cases of Trisomy 18, also called Edwards syndrome, are not inherited but occur as random events during the formation of eggs and sperm. An error in cell division called nondisjunction results in a reproductive cell with an abnormal number of chromosomes. For example, an egg or sperm cell may gain an extra copy of chromosome 18. If one of these atypical reproductive cells contributes to the genetic makeup of a child, the child will have an extra chromosome 18 in each of the body’s cells.Mosaic trisomy 18 is also not inherited. It occurs as a random event during cell division early in embryonic development. As a result, some of the body’s cells have the usual two copies of chromosome 18, and other cells have three copies of this chromosome.Partial trisomy 18 can be inherited. An unaffected person can carry a rearrangement of genetic material between chromosome 18 and another chromosome. This rearrangement is called a balanced translocation because there is no extra material from chromosome 18. Although they do not have signs of trisomy 18, people who carry this type of balanced translocation are at an increased risk of having children with the condition.Canavan disease is a type of leukodystrophy and a degenerative disorder that causes progressive damage to nerve cells in the brain. It is inherited in an autosomal recessive manner.Cystic Fibrosis is the most common lethal recessive disease of white people, with a carrier frequency of 1:25 and is inherited in an autosomal recessive manner.Galactosaemic is autosomal recessive and due to mutations in the GALT gene.Phenylketonuria is the most common inborn error of metabolism in the UK with an incidence of 1:10,000 and a carrier rate of 1:50.

History of recurrent infections and failure to thrive (probably due to pancreatic enzyme insufficiency) is highly suggestive of cystic fibrosis. Pseudomonas has been identified as an important respiratory pathogen in patients with cystic fibrosis.

The commonest time for bacterial meningitis is in the 1st month of life and group B Streptococcus is the commonest organism. The anterior fontanelle is full, but does not bulge with normal flexion. Neurological manifestations include seizures, irritability, poor tone, lethargy and tremors, however no findings of sensorineural deafness have been noted. One of the risk factors for introduction of meningeal infection is Meningomyelocele.

Foreign body aspiration (FBA) commonly occurs in children aged 1–3 years. FBA typically presents with sudden onset of coughing and choking, followed by stridor and dyspnoea. Obstruction of the larynx or trachea is a potentially life-threatening situation that causes severe respiratory distress, cyanosis, and suffocation. Most commonly, the foreign body (FB) becomes lodged in the main and intermediate bronchi| approx. 60% of FB are located in the right main bronchus due to the more vertical orientation compared to the left main bronchus. Reduced breath sounds on the one side only would not be explained by a tracheal obstruction as it would cause reduced breath sounds bilaterally and a more severe clinical picture.

Measles and chickenpox are spread by droplets. Thus, patients should be isolated. Rheumatic fever and post-streptococcal glomerulonephritis are immune mediated diseases that don’t require isolation. Herpetic gingivostomatitis spreads by direct transmission of infected secretions to the stratified squamous epithelium. HSP is not an infectious disease.

The clinical presentation is suggestive of congenital rubella syndrome. The classic triad of presenting symptoms includes sensorineural hearing loss, ocular abnormalities (cataract, infantile glaucoma, and pigmentary retinopathy) and congenital heart disease (patent ductus arteriosus and pulmonary artery stenosis). Other findings in congenital rubella syndrome include CNS abnormalities (mental retardation, behavioural disorders, encephalographic abnormalities, hypotonia, meningoencephalitis, and microcephaly), hepatosplenomegaly, and jaundice.

Biliary atresia is a rare condition that usually becomes symptomatic 2 to 8 weeks after birth. It can be congenital or acquired. Typical symptoms include jaundice, weight loss, dark urine and pale stools.

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.