Chickenpox is a highly communicable viral disease caused by human (alpha) herpesvirus 3 (varicella-zoster virus, VZV). It is transmitted from person to person by direct contact (touching the rash), droplet or air born spread (coughing and sneezing).

The patient’s symptoms are most likely due to phenytoin intake.Note:Hypertrichosis occurs in 5–12% of patients on phenytoin and is most prominent on the extremities. Other options:- Hypertrichosis is the excess hair growth, whereas hirsutism is the development of male-pattern-dependent hair growth, as seen in polycystic ovarian syndrome. – A Becker’s naevus is associated with localised hypertrichosis in the naevus. – Cyclosporine intake can typically lead to diffuse hair growth that begins within 2–4 weeks of starting the drug. – Hereditary gingival fibromatosis is associated with variable hypertrichosis occurring on the eyebrows, face, limbs and mid-back.

Hypogonadotropic hypogonadismIn Kallmann syndrome: impaired migration of GnRH cells and defective olfactory bulb → ↓ GnRH in hypothalamus → ↓ FSH and ↓ LH → ↓ testosterone and ↓ oestrogenIn hypothalamic and/or pituitary lesions: ↓ pituitary gonadotropins (↓ FSH and ↓ LH) → ↓ testosterone and ↓ oestrogen

The most common cause for acute bloody diarrhoea in a 10-year-old child is Campylobacter.Note:Campylobacter is the most common bacterial cause of gastroenteritis in the UK. It typically presents with bloody diarrhoea, fever, abdominal pain and vomiting. The primary source of Campylobacter is uncooked poultry. Treatment is generally supportive unless the child is immunosuppressed or the symptoms are persistent.Other options:- E. coli 0157:H7: It causes acute haemorrhagic diarrhoea, usually afebrile. It can lead to haemolytic uremic syndrome (haemolytic anaemia, acute renal failure and thrombocytopenia), which is the commonest cause of acute renal failure in children.- Rotavirus: It rarely causes bloody diarrhoea.- Salmonella and Yersinia: While they can cause bloody diarrhoea, they are much less common compared to Campylobacter.

ASD is an acyanotic congenital heart disease, characterized by the failure of the interatrial septum to form completely, which results in the mixing of left and right-sided blood. There are various types of ASD, some of them are ostium primum septal defect and patent foramen ovale. Clinical findings associated with ASD are a systolic ejection murmur, fixed splitting of second heart sound, prolonged PR interval, both left and right axis deviation (primum and secundum ASD, respectively). The most common finding is an incomplete right bundle branch block.

The most serious side effects of IV Lorazepam include hallucinations, agitation, confusion, amnesia and muscle weakness.

The most probable cause for the patient’s symptoms would be pes anserine bursitis.Translated, pes anserinus means goose feet. It is the term used to describe the unified bursa enclosing the tendons of the sartorius, gracilis and semitendinous muscles inserting into the anteromedial proximal tibia.Pes anserine bursitis is common in people doing sports due to overuse injuries. The main sign is of pain in the medial part of the proximal tibia. As the McMurray test is negative, medial meniscal injury is excluded.

Clinical signs of early pregnancy-Amenorrhoea-Nausea and vomiting -Breast enlargement and tenderness -Hyperpigmentation of the areola and formation of linea nigra: Most likely due to increased levels of melanocyte-stimulating hormone produced by the placenta -Increased urinary frequency-Fatigue-Cravings for or aversions to certain foods-Abdominal bloating and constipation

The boy needs re-hydration and hydro-electrolytic re-balancing due to fluid losses from the gastroenteritis and subsequent dehydration.

H. pylori release the enzyme urease that has the ability to split urea releasing nitrogen. This process increases the pH in the gastric antrum making the gastric pH less acidic.Helicobacter pylori:It is a spiral, microaerophilic, gram-negative bacterium. It is one of the most common causes of antral gastritis in children. Ulcers are less common in children compared with adults| however, when they occur, they are more common in the duodenum.The presence of H.pylori can be confirmed by:- Stool antigen test (preferred)- Serology- Endoscopy with biopsy and culture- Rapid urease testsH.pylori gastritis may be associated with:- Iron deficiency anaemia- Gastric malignancy Management:The treatment is with triple therapy- two antibiotics, and an antacid.Treatment failure is often attributed to a possible worldwide increase in macrolide resistance. Interestingly, children have higher antibiotic resistance compared with adults.Note:Zollinger-Ellison syndrome (ZES) causes gastrin-secreting tumours and can present as a part of multiple endocrine neoplasia type 1 (MEN1)- an autosomal dominant disorder.

The azygos lobe is usually well seen on the chest radiograph, where it is limited by the azygos fissure, a fine, convex (relative to the mediastinum) line that crosses the apex of the right lung.

Incontinentia pigmenti is a genetic condition that affects females more than males. It usually manifests in the skin but can affect other parts of the body as well. It presents with a blistering rash that may evolve into wart-like growths. Hyperpigmentation and hair loss are also present, as well as eye and teeth abnormalities. Clinically there are three phases: 1- the bullous phase – crops of vesicles appear in the first 2 weeks of life|2- the papular phase – warty papules that flatten out over the skin| and 3- the hyperpigmented phase – pigmentary changes in the form of whorls and streaks that are hypo- and hyperpigmented in nature.

Juvenile angiofibroma (JA) is a rare benign vascular lesion of the skull base that affects young adolescent males. The management of JA is challenged by the abundant vascular blood supply of the lesion, along with the complex anatomy of the skull base and the young age of the affected population. JA typically affects the male population, most commonly between 9 and 19 years of age. The most frequent symptoms are nasal obstruction and epistaxis. Nasal obstruction may be bilateral despite the unilaterality of the lesion, due to nasopharyngeal extension as well as deviation of the nasal septum by the expansile lesion. Epistaxis is usually brisk and intermittent. Purulent nasal discharge and facial pain can be due to sinus drainage pathway obstruction, and conductive hearing loss indicates obstruction of the eustachian tube.

Jaundice is considered pathologic if it presents within the first 24 hours after birth. Although up to 60 percent of term new-borns have clinical jaundice in the first week of life, few have significant underlying disease.1,2 However, hyperbilirubinemia in the new-born period can be associated with severe illnesses such as haemolytic disease, metabolic and endocrine disorders, anatomic abnormalities of the liver, and infections. The risk factors here is the mothers blood ground which suggests the cause is fetal-maternal blood group incompatibility.

Hydrocephalus is a serious medical condition resulting from excessive accumulation of cerebrospinal fluid in the brain leading to abnormal pressure build-up inside the brain. Hydrocephalus can be categorized into two types according to the flow of CSF between the ventricles. When the CSF flows freely between the ventricles, but is blocked after it exits the ventricular system, the hydrocephalus is said to be a communicating hydrocephalus. When the flow of CSF within the ventricles is blocked, the resulting hydrocephalus is termed as obstructive, or non-communicating. The communicating hydrocephalus is caused by insufficient reabsorption of CSF in the subarachnoid space, which is also observed in cases of bacterial meningitis, in which inflammatory process leads to the thickening of the leptomeninges and thereby reduces CSF reabsorption. Arnold Chiari malformation is associated with obstructive hydrocephalus due to blocked ventricles. Congenital aqueduct stenosis causes the blockage of third and lateral ventricles. Congenital atresia of the foramen of Monro leads to blocked lateral ventricles and thus results in obstructive hydrocephalus. Tumour of the posterior fossa is associated with blockage of the fourth ventricle outflow.

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.

All of the presenting features of the child are suggestive raised intracranial pressure. Thus, urgent treatment with 20% Mannitol can improve the child’s condition. Mannitol is an osmotic diuretic that is used in the treatment of raised intracranial pressure. It should be avoided in hypovolaemia because of its diuretic effects. Other options:- Head up at 15°: Keeping the head up at 20° in the midline will aid venous drainage. – Maintain CO2 at 5 kPa: If there is an acute rise in intracranial pressure, then lowering the CO2 to 4–4.5 kPa as a temporary measure can be beneficial. However, this must be only short-lived since it causes vasoconstriction and can impair cerebral blood flow. – 10% glucose bolus: Maintaining normoglycemia in traumatic brain injury is important. – 0.9% saline infusion: Hypertonic saline infusion of 3% can reduce intracranial pressure. 0.9% saline as a bolus could be beneficial if there were hypotension.

Spontaneous intestinal perforation (SIP) of the new-born, also referred to as isolated perforation or focal intestinal perforation (FIP) of the new-born, is a single intestinal perforation that is typically found at the terminal ileum. SIP occurs primarily in preterm infants with very low birth weight (VLBW, birth weight <1500 g) and extremely low birth weight (ELBW, birth weight <1000 g), umbilical catheter placement, maternal drug use and twin-to-twin transfusion syndrome. SIP is a separate clinical entity from necrotizing enterocolitis, the most severe gastrointestinal complication of preterm infants.

The most appropriate procedure in the surgical management of this child would be to perform an appendicostomy for anterior continence enemas (Malone procedure).Idiopathic constipation leading to faecal incontinence is managed in a stepwise progression, first with laxatives such as movicol, enemas and stronger laxatives and in younger children inter-sphincteric injection of botox may be performed. Following this either anal irrigation or antegrade continence enemas are performed. Appendicostomy for anterior continence enemas allow colonic washouts and thereby rapid achievement of continence.Other options:- Defunctioning Ileostomy: Although an option in extreme cases, an ACE stoma would be more appropriate in this child.- Laparotomy for resection of the megarectum is performed if ACE stoma fails due to megarectum.- Left hemicolectomy is a procedure reserved for slow-transit colons to increase transit time.- Bishop-Koop stoma: It is a procedure of historical significance. It is a way of washing out and managing meconium ileus.

From the options mentioned here, the closest diagnosis is haemophilia. This is a mixed picture, as a purpuric rash on the buttocks does not correlate with this diagnosis. However, the most appropriate diagnosis is haemophilia.

Lesch-Nyhan syndrome is a condition that occurs almost exclusively in males. This condition is inherited in an X-linked recessive pattern It is characterized by neurological and behavioural abnormalities and the overproduction of uric acid. Uric acid is a waste product of normal chemical processes and is found in blood and urine. Excess uric acid can be released from the blood and build up under the skin and cause gouty arthritis (arthritis caused by an accumulation of uric acid in the joints). Uric acid accumulation can also cause kidney and bladder stones.The nervous system and behavioural disturbances experienced by people with Lesch-Nyhan syndrome include abnormal involuntary muscle movements, such as tensing of various muscles (dystonia), jerking movements (chorea), and flailing of the limbs (ballismus). People with Lesch-Nyhan syndrome usually cannot walk, require assistance sitting, and generally use a wheelchair. Self-injury (including biting and head banging) is the most common and distinctive behavioural problem in individuals with Lesch-Nyhan syndrome.

Being anatomically situated immediately posterior to the subclavius muscle and the medial part of the clavicle, the subclavian vein is at the highest risk of injury in the above patient.As a direct tributary of the brachiocephalic vein, it’s injury poses a high risk of massive bleeding.The brachiocephalic vein rests on the first rib, below and in front of the third part of the subclavian artery, and then on scalenus anterior which separates it from the second part of the artery (posteriorly).Anatomy of the clavicle:The clavicle extends from the sternum to the acromion and helps prevent the shoulder falling forwards and downwards.

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

Urine culture and sensitivity is used to diagnose a urinary tract infection (UTI). A mid-stream clean catch urine sample is the most common type of sample collected. It is important to follow the clean catch process to have accurate results from an uncontaminated sample. Urine cultures can also check for infections of the bladder or kidney.

Turner syndrome (TS) is one of the most common genetic disorders| occurs with an incidence of I: 2,500 female live births. It results from complete or partial chromosome X monosomy. TS is associated with abnormalities of the X chromosome and characteristic clinical features of short stature, gonadal dysgenesis, sexual developmental deficiencies, cardiac and/or renal defects, webbed neck, low-set ears, skeletal deformities including cubitus valgus, a propensity to ear infections and hearing deficits.

The embryonic period comprises of the first 8 weeks of pregnancy. It is divided into a preembryonic phase (from the 1st to the 3rd week), in which the three germinal layers arise, and into the embryonic phase proper (from the 4th to 8th week), in which the embryonic organ anlagen arise.

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.

Also known as the hyoid arch, it forms the side and front of the neck. From its cartilage develops the styloid process, stylohyoid ligament and lesser cornu of the hyoid bone. The muscular derivatives include the muscles of facial expression, stapedius, stylohyoid and the posterior belly of the digastric. All these are innervated by cranial nerve VII but migrate into the area of the mandibular arch.

Henoch–Schönlein purpura (HSP), also known as IgA vasculitis, is a disease of the skin, mucous membranes, and sometimes other organs that most commonly affects children. In the skin, the disease causes palpable purpura (small, raised areas of bleeding underneath the skin), often with joint pain and abdominal pain. It is an acute immunoglobulin A (IgA)–mediated disorder. The tetrad of purpura, arthritis, kidney inflammation, and abdominal pain is often observed.

Pityriasis rosea is a common, acute exanthem of uncertain aetiology. Viral and bacterial causes have been sought, but convincing answers have not yet been found. Pityriasis rosea typically affects children and young adults. It is characterized by an initial herald patch, followed by the development of a diffuse papulosquamous rash. The herald patch often is misdiagnosed as eczema. Pityriasis rosea is difficult to identify until the appearance of characteristic smaller secondary lesions that follow Langer’s lines (cleavage lines). Several medications can cause a rash similar to pityriasis rosea, and several diseases, including secondary syphilis, are included in the differential diagnosis.