The most common etiological agent for retinitis in HIV infected patients is cytomegalovirus (88.63% of retinitis in HIV/AIDS patients). Most patients have a CD4 lymphocyte count less than 50/μL, which can represent the susceptibility to this type of retinitis when lymphocyte count falls below this threshold. The treatment consists of systemic intravenous administration of Ganciclovir or Foscarnet at a first stage of induction, followed by the maintenance treatment with oral administration of Ganciclovir.

Not uncommonly, children insert a foreign body in their ear canal and do not mention it to their parents. If any pain accompanies purulent drainage, the possibility of a foreign body in the ear canal should be considered. A patient with a foreign body in place will not improve until it is removedOrganic foreign bodies tend to elicit inflammatory reactions. In the ear, they predispose to otitis externa, suppurative otitis media and hearing loss

Congenital hypothyroidism results from insufficient levels of thyroid hormone in the body since birth, which is either due to dysgenesis of the thyroid gland or dyshormonogenesis. The important features of this disease include coarse facial features (macroglossia, large fontanelles, depressed nasal bridge, hypertelorism, etc.), failure to thrive, cardiomegaly, hypotonia, umbilical hernia, and low core body temperature among many others. Frontal bossing is the usual feature of rickets and acromegaly. Mitral regurgitation is not usually associated with congenital hypothyroidism.

The sinus venosus is a large quadrangular cavity which precedes the atrium on the venous side of the chordate heart. It exists distinctly only in the embryonic heart (where it is found between the two venae cavae)| however, the sinus venosus persists in the adult. In the adult, it is incorporated into the wall of the right atrium to form a smooth part called the sinus venarum, which is separated from the rest of the atrium by a ridge of fibres called the crista terminalis. The sinus venosus also forms the SA node and the coronary sinus.

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.

The most probable diagnosis for this patient is Maple syrup urine disease (MSUD).Note:- Healthy new-borns have blood sugars between 3.3 and 5 mmol/L- Neonatal hypoglycaemia is glucose < 2.2 mmol/L if measured in the first 3 days of life.- Neonatal hypoglycaemia is glucose < 2.5 mmol/L after the first 3 days of life.Causes of persistent hypoglycaemia include:- Preterm- IUGR- SGA- Hyperinsulinism due to maternal diabetes- Beckwith-Wiedemann syndrome- Hypoxia at birth- Sepsis- Cardiopulmonary disease- Inborn errors of metabolism- Hepatic enzyme deficiencies- Glycogen storage disease

The physical features and developmental delay are the key aspects in the given scenario. The child in question shows features of gross motor and social developmental delay and has physical features indicative of Prader-Willi syndrome (hypopigmentation, esotropia, disproportionately small hands and feet, loss of central muscle tone and undescended testes). Children with Prader-Willi syndrome can present with failure to thrive until ,12-18 months, at which point, hyperphagia and obesity become more prominent. Other options:- Although Klinefelter syndrome can present with delayed development, undescended/small testes and reduced muscle power, the presence of small hands/feet, hypopigmentation and failure to thrive are not characteristic features. – Marfan syndrome presents with different physical features (arachnodactyly, cardio-respiratory complications and skin changes, amongst others) than those associated with Prader-Willi syndrome. – DiGeorge can manifest with developmental delay, hypotonia and feeding difficulties. However, this clinical scenario does not report any of the typical facial features, hearing abnormalities or cardiac abnormalities that are typically caused by DiGeorge syndrome. – Russell-Silver syndrome can cause developmental abnormalities, poor muscle tone and power (poor head control and muscle function), feeding difficulties and poor growth during the post-natal period and infancy. However, characteristic facial (small, triangular face, blue sclerae) and skeletal abnormalities (limb asymmetry, finger abnormalities) are not present. Therefore, Prader-Willi syndrome is the most appropriate diagnosis for this patient.Note:Prader-Willi syndrome is an example of genetic imprinting where the phenotype depends on whether the deletion occurs on a gene inherited from the mother or father: In Prader-Willi syndrome, it is the paternal gene that is deleted from the long arm of chromosome 15, while in Angelman syndrome the maternal gene is deleted. Prader-Willi syndrome can occur due to the microdeletion of paternal 15q11-13 (70% of cases) maternal uniparental disomy of chromosome 15.

Tuner’s syndrome is not associated with arachnodactyly.Arachnodactyly is seen in the following conditions:- Marfan syndrome- Homocystinuria- Ehlers-Danlos syndrome- Congenital contractural arachnodactylyOther rare syndromes include:- Loeys-Dietz syndrome- Antley-Bixler syndrome- Marden-Walker syndrome- Lujan-Frinz syndrome- Haim-Munk syndrome- Marden-Walker syndrome- Spondylocostal dysostosis

Removal of foreign bodies from the ear is indicated whenever a well-visualized foreign body is identified in the external auditory canal. Insects are better extracted with suction than with forceps or hooks. From the given answers, irrigation with warm water is the most suitable answer.

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.

The main cause of growth hormone (GH) deficiency is a pituitary tumour or the consequences of treatment of the tumour including surgery and/or radiation therapy.Sheehan’s syndrome (SS) is postpartum hypopituitarism caused by necrosis of the pituitary gland. It is usually the result of severe hypotension or shock caused by massive haemorrhage during or after delivery. Patients with SS have varying degrees of anterior pituitary hormone deficiency.Laron syndrome is Insulin-like growth factor I (IGF-I) deficiency due to GH resistance or insensitivity due to genetic disorders of the GH receptor causing GH receptor deficiency.

The T wave represents ventricular repolarization. Other options:- P wave:Depolarization that spreads from the SA node throughout the atria. The wave lasts 0.08 to 0.1 seconds (80-100 ms).The isoelectric period after the P wave represents the time in which the impulse is travelling within the AV node.- P-R interval:Time from the onset of the P wave to the beginning of the QRS complex. The wave ranges from 0.12 to 0.20 seconds in duration.Represents the time between the onset of atrial depolarization and the onset of ventricular depolarization- QRS complex:It represents ventricular depolarization. The duration of the QRS complex is normally 0.06 to 0.1 seconds.- ST-segment:The isoelectric period following the QRS. It represents the period in which the entire ventricle is depolarized and roughly corresponds to the plateau phase of the ventricular action potential- U wave: It is a small positive wave which may follow the T wave. It represents the last remnants of ventricular repolarization.- Q-T intervalIt represents the time for both ventricular depolarization and repolarization to occur, and therefore roughly estimates the duration of an average ventricular action potential.The interval ranges from 0.2 to 0.4 seconds depending upon heart rate.At high heart rates, ventricular action potentials shorten in duration, which decreases the Q-T interval. Therefore the Q-T interval is expressed as a corrected Q-T (QTc) by taking the Q-T interval and dividing it by the square root of the R-R interval (interval between ventricular depolarizations). This allows an assessment of the Q-T interval that is independent of heart rate.The normal corrected Q-Tc interval is less than 0.44 seconds.

When topical agents are insufficient or not tolerated, or in cases of moderate to severe acne, especially when the chest, back and shoulders are involved, systemic antibiotics are often considered the next line of treatmentSystemic antibiotics should not be used to treat mild acne because of the risk of increasing resistance. The additional use of nonantibiotic topical agents in combination with oral antibiotics should be considered. Topical retinoids with oral antibiotics may give a faster response and be more effective than either drug used alone.Treatment with tetracyclines and erythromycin reduces P. acnes within the follicles, thereby inhibiting the production of bacterial-induced inflammatory cytokines. These agents also have inherent anti-inflammatory effects, such as suppressing leukocyte chemotaxis and bacterial lipase activity.

Various types of birthmarks are commonly seen in children of different age groups. Birthmarks can be broadly classified as pigmented and vascular birthmarks. Port-wine stain (nevus flammeus) is an example of a vascular birthmark, and is characterized by a reddish-purple discoloration of the skin due to abnormal underlying skin vasculature. Port-wine stain has also been associated with vascular diseases like Sturge-weber syndrome, which is a congenital neurocutaneous disorder. In Sturge-weber syndrome, the port-wine stain affects the skin around the ophthalmic branch of trigeminal nerve.

Drug withdrawal symptoms after a period of substance abuse can lead to a range of symptoms. Amphetamines are known to cause hypersomnia, hyperphagia, and irritability, as well as vivid dreams as a result of withdrawal. Similar symptoms are found in cocaine withdrawal. Alcohol withdrawal presents with symptoms such as insomnia, tremulousness and delirium. Ecstasy withdrawal includes irritation, mood swings, fatigue and insomnia. Heroin withdrawal presents with symptoms which include dilated pupils, insomnia, abdominal cramps and muscle aches. Withdrawal from prolonged cannabis use can cause depression, anxiety restlessness and insomnia.

A teratoma is a tumour containing tissue elements that are similar to normal derivatives of more than one germ layer. They usually contain skin, hair, teeth and bone tissue and are more common in children, behaving as a benign tumour. After puberty, they are regarded as malignant and can metastasise.

The most probable diagnosis for this patient would be a duplex kidney with an ectopic ureter inserting below the bladder neck. Rationale: The Weigert-Myer law states that the upper moiety ureter inserts inferior and medial to the lower moiety ureter. Other options:- Horseshoe kidney would display as a single pelvic kidney on an ultrasound scan.- Ureterocele would be a cystic lesion within the bladder or may prolapse at birth. – Continence should not be affected by polycystic kidney disease. – The overactive bladder would cause frequency and urgency, neither of which is mentioned in the history.

This patient is most likely suffering from hand, foot mouth disease which is caused by coxsackie virus A16. Its incubation period ranges from 5-7 days and only symptomatic treatment is required.

Neurofibromatosis type 2, also known as schwannomin, is an autosomal dominant genetic disease caused by mutation of the merlin gene located on chromosome 22. Merlin is a tumour suppressor protein, which is responsible for controlling cell shape, growth and adhesion, and is predominantly found in nervous tissue. Its mutation increases the risk of tumour development especially bilateral vestibular schwannomas, the hallmark of neurofibromatosis 2.

While the cause for Bell’s palsy is still under debate, it is observed that Bell’s palsy is often preceded by a viral infection. Bell’s Palsy:Bell’s palsy (idiopathic facial palsy) is an acute unilateral lower motor neurone palsy. It typically occurs two weeks after viral infection such as Epstein–Barr, herpes simplex, herpes zoster or mumps. A careful assessment may suggest an alternative aetiology for the acute onset of weakness, e.g. acute otitis media, Lyme disease, hypertension. Causes:In childhood, Bell’s palsy is probably a post-infectious (i.e. immune-mediated) phenomenon, while in adults, there is increasing evidence that the majority of cases follow reactivation of previous HSV infection. Management:The prognosis is generally good in childhood with full recovery in the majority. However, permanent weakness is observed in around 5%. Steroids and acyclovir may have some benefit in adults with recent onset of weakness, but the evidence of the treatment benefit is much less convincing in childhood. Exposure keratitis is an important complication and children should be managed with eye drops and taping of the eyelid at night until recovery is complete.

Presentation can vary by individual. Early stages are often characterized by malaise, fatigue, and lethargy. One to 3 months of inadequate intake can lead to anaemia, myalgia, bone pain, easy bruising (Figure 3), swelling, petechiae, perifollicular haemorrhages, corkscrew hairs, gum disease, poor wound healing, mood changes, and depression. Perifollicular haemorrhages and easy bruising are often first seen in the lower extremities, as capillary fragility leads to an inability to withstand hydrostatic pressure. Late stages of scurvy are more severe and life threatening| common manifestations include generalized oedema, severe jaundice, haemolysis, acute spontaneous bleeding, neuropathy, fever, convulsions, and death.

The sign being elicited in this patient is Nikolsky’s sign. Based on the findings, the patient is suffering from toxic epidermal necrolysis.Nikolskys sign: Rubbing the skin causes exfoliation of the outer layer and usually blistering within a few minutes. Other options:- Cullen’s sign: Periumbilical bruising due to intra-abdominal haemorrhage. If the discolouration is seen in the flanks, it is called Cullen’s sign. Underlying pathology includes ruptured ectopic pregnancy and haemorrhagic pancreatitis. – Forscheimer’s sign: It is a fleeting exanthem that is seen as small, red spots (petechiae) on the soft palate. Associated with rubella and glandular fever. Gorlin’s sign: It is the ability to touch the tip of the nose with the tongue. Increased incidence in children with connective tissue disorders, e.g. Ehler Danlos syndrome. – Auspitzs sign: These are small bleeding points left behind when psoriatic scales are lifted off. It is not a very sensitive or specific sign. Other cutaneous signs include:- Hair collar sign: It is a collar of hypertrichosis around an area of cranial dysraphism.- Hertoghe’s sign (Queen Anne’s sign): It is the loss of lateral one-third of eye-brows. It is associated with numerous conditions, including lupus, HIV, and hypothyroidism. – Dariers sign: It is the swelling, itching and erythema that occurs after stroking skin lesions of a patient with systemic mastocytosis or urticarial pigmentosa. – Dermatographism: Rubbing the skin causes a raised, urticarial lesion. – Koebners phenomenon: It is the appearance of new skin lesions in areas of trauma.- Breakfast, lunch, and dinner sign: Linear pathway of a group of three to five papules caused by the common bed bug, Cimex lectularius. – Buttonhole sign: In type 1 neurofibromatosis, neurofibromas can be invaginated with the finger back into the subcutis. The nodule will reappear after the release of pressure. The sign is also positive for dermatofibromas. – Crowe’s sign: Axillary freckling seen in type I neurofibromatosis.

Cystic fibrosis is an autosomal recessive inherited disorder that affects the lungs or the pancreas. In the case of an affected child whose parents do not have the disorder but carry one copy of the mutated gene, each sibling has a 50% chance of being a carrier of the disease. They can inherit one copy of the gene from each parent. There is a 25 % chance that the child may inherit both mutated genes and be homozygous for the trait.

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.

The clinical picture suggests intracranial haemorrhage which is uncommon but prevalent in pre-term babies. The rest of the options suggest peripheral causes which do not affect the central function.

Bilirubin encephalopathy (BE), also known as kernicterus is a preventable complication of neonatal jaundice. Bilirubin deposits in the basal ganglia, hippocampus, geniculate bodies and cranial nerve nuclei, exerting direct neurotoxic effects and causing mass-destruction of neurons by apoptosis and necrosis.The clinical features of this diagnosis have been well described and can be divided into 3 stages:Phase 1 (first few days of life): Decreased alertness, hypotonia, and poor feeding are the typical signs. Obviously, these are quite nonspecific and could easily be indicative of a multitude of neonatal abnormalities. A high index of suspicion of possible BIND at this stage that leads to prompt intervention can halt the progression of the illness, significantly minimizing long-term sequelae. Of note, a seizure is not typically associated with acute bilirubin encephalopathy.Phase 2 (variable onset and duration): Hypertonia of the extensor muscles is a typical sign. Patients present clinically with retrocollis (backward arching of the neck), opisthotonos (backward arching of the back), or both. Infants who progress to this phase develop long-term neurologic deficits. Phase 3 (infants aged >1 wk): Hypotonia is a typical sign.

3-year-old milestones:Social and Emotional:- Copies adults and friends – Shows affection for friends without prompting – Takes turns in games – Shows concern for crying friend – Understands the idea of “mine” and “his” or “hers” – Shows a wide range of emotions – Separates easily from mom and dad – May get upset with major changes in routine- Dresses and undresses self Language/Communication- Follows instructions with 2 or 3 steps – Can name most familiar things – Understands words like “in,” “on,” and “under” – Says first name, age, and sex- Names a friend – Says words like “I,” “me,” “we,” and “you” and some plurals (cars, dogs, cats) – Talks well enough for strangers to understand most of the time – Carries on a conversation using 2 to 3 sentencesCognitive (learning, thinking, problem-solving)- Can work toys with buttons, levers, and moving parts – Plays make-believe with dolls, animals, and people – Does puzzles with 3 or 4 pieces – Understands what “two” means – Copies a circle with a pencil or crayon – Turns book pages one at a time – Builds towers of more than 6 blocks – Screws and unscrews jar lids or turns the door handleMovement/Physical Development- Climbs well – Runs easily – Pedals a tricycle (3-wheel bike) – Walks up and downstairs, one foot on each stepDoing up buttons is a skill more usually seen in 5-year-olds.

Tinea corporis is a type of dermatophytosis, caused by Trichophyton or Microsporum. The disease is highly contagious and rapidly spreads to all the areas of the body, including the glabrous skin. It produces an erythematous itchy skin rash with a central area of clearance surrounded by raised scaly borders. Lesions can appear as concentric circles that overlap, referred to as tinea imbricate.

Gilbert’s syndrome is an autosomal recessive condition that results from defective bilirubin conjugation due to a deficiency of UDP glucuronyl transferase – 1. The prevalence is approximately 1-2% in the general population.The clinical presentation of Gilbert’s syndrome include:- Unconjugated hyperbilinaemia- Jaundice can occur during an intercurrent illnessManagement:Blood investigations usually reveal a rise in bilirubin following prolonged fasting or intravenous nicotinic acid.No treatment required for these patients.Other options:- CYP2C9 deficiency causes reduced warfarin metabolism, and subsequent enhanced drug effects. – Pancreatic disease, cholestasis, excessive alcohol consumption and certain drugs are common causes of raised GGT levels- Defective hepatocyte excretion of conjugated bilirubin is related to the pathophysiology of Dubin-Johnson syndrome- Reduced CYP2C19 levels can lead to the disordered metabolism of clopidogrel and other drugs such as proton-pump inhibitors, anticonvulsants and sedatives.

The most probable diagnosis for this patient, according to the clinical scenario provided is tuberous sclerosis. It is an autosomal-dominant disorder characterised by hamartomas located throughout the body, often prominently involving the central nervous system and skin. Two loci on chromosomes 9 and 16 have been identified to be associated with this condition. The condition has a variable expression and penetrance and is further characterised by:- Seizures (usually infantile spasms)- Developmental delay- Facial/cutaneous angiofibromas (adenoma sebaceum)- Periungual fibromas (pink projections from the nail folds)- Shagreen patches (leathery thickenings of the skin usually on the back) – Ash leaf macules (areas of depigmentation that become visible under a Wood’s light)- Fundoscopy may reveal white streaks along the fundal vessels.