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Question 1
Correct
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Retinopathy of prematurity (ROP) is a potentially blinding disease if not managed adequately. Which of the following is a complication of ROP in an infant?
Your Answer: Retinal detachment
Explanation:Retinopathy of prematurity affects infants born early, and is due to the abnormal growth of retinal vasculature as opposed to vascular occlusion often see in adults. Though most babies with ROP can see normally, the most significant complication of ROP Is retinal detachment which can lead to blindness. Other structures in the eye such as the optic nerve or the fovea however, are not affected. Children may develop nystagmus as a result of poor sight in the affected eye(s).
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This question is part of the following fields:
- Ophthalmology
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Question 2
Incorrect
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A 16-month-old boy presented following a 20 min seizure. He was given 5 mg per rectum (PR) diazepam to terminate the seizure and is still only responding to voice 6 hours later. He was diagnosed with measles five days prior to this episode.Which of the following is the most probable cause of his symptoms?
Your Answer: Acute disseminated encephalomyelitis
Correct Answer: Encephalitis
Explanation:The most probable cause for the patient’s presenting symptoms is encephalitis secondary to measles infection.Encephalitis:Encephalitis occurs in 1 per 1000 measles cases. It usually presents within 1-14 days of the rash, usually day 5. It may present with fever, headache, vomiting, stiff neck, meningeal irritation, drowsiness, seizures, reduced consciousness; 15% will have neurological sequelae; 10% mortality.Other options:- Acute disseminated encephalomyelitis occurs in 1 per 1000 measles cases. It is thought to be a postinfectious immune response. Clinical manifestations include fever, headache, neck stiffness, seizures and mental status changes. It could fit this presentation although it tends to present in the recovery phase of measles infection, typically two weeks after the exanthem. In contrast, encephalitis tends to occur within a few days of the rash.- The history is not that of a typical febrile seizure as it lasted >15 minutes. He has also not recovered consciousness at 4 hours. The diazepam should have been eliminated within 4 hours and so should no longer be contributing to his reduced level of consciousness. Also, the history states the recent diagnosis of measles, and so complications of measles should be considered.- Intracranial bleed secondary to thrombocytopenia: Measles is not known to cause thrombocytopenia.- Subacute sclerosing panencephalitis (also known as Dawson’s encephalitis): This is an extremely rare complication of measles. It is a progressive degenerative disease of the central nervous system that occurs 7-10 years after a measles infection. The treatment for SSPE is mainly intraventricular interferon therapy through an Ommaya reservoir. The prognosis is poor, and it is usually fatal.
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This question is part of the following fields:
- Neurology And Neurodisability
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Question 3
Correct
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A 16 year old boy was admitted with severe pain and swelling of his scrotum following a kick to the groin. What is the most appropriate management that can be done at this stage?
Your Answer: Exploratory surgery
Explanation:The most worrying condition is testicular torsion and to exclude it exploratory surgery is required.
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This question is part of the following fields:
- Paediatric Surgery
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Question 4
Correct
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A baby is born with complications including microcephaly, hepatosplenomegaly and elevated total bilirubin. Which of the following is the most likely diagnosis in this case?
Your Answer: Cytomegalovirus (CMV)
Explanation:CMV infection is usually asymptomatic in adults. However, if the mother is infected for the first time during pregnancy then there is high chances of this infection passing on to the foetus. CMV infection can cause blindness, deafness, learning difficulties, restricted growth etc. Hepatitis B, herpes simplex, syphilis and HIV do not present with these classical signs of CMV infection in new-borns. It is estimated that 10 stillbirths occur in England and Wales every year due to CMV infection. The foetus is most at risk in early pregnancy. There is no effective prevention.
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This question is part of the following fields:
- Infectious Diseases
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Question 5
Incorrect
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A 15-month-old child is due for his measles, mumps and rubella (MMR) vaccines. He is feverish due to an acute otitis media and the mother gives a family history of egg allergy. What is the most appropriate action?
Your Answer: Do not give vaccine
Correct Answer: Defer immunization for two weeks
Explanation:Vaccines should not be given to a feverish child.
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This question is part of the following fields:
- Immunology
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Question 6
Correct
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In a double blind trial of a new diabetes medication, 25% more in the treated group responded positively than those in the control group (95% CI 10% to 50%; P=0.004)
Your Answer: The therapy benefits an additional 1 in 4 (95% CI 2 to 10), patients who receive it
Explanation:In the final result of this double blind study, 25% or one in four of patients who received the treatment responded positively. Though the difference is significant at P<0.05, it is better to present this as a significant difference at 0.4%. The number needed to treat (NNT) is defined as the inverse of the absolute risk reduction. Taking this as 0.25 (25%), the NNT is 1/0.25 = 4. However given the 95% confidence interval is between 10-50% for absolute risk reduction, the NNT with 95% CI is between 2 and 10. Therefore we cannot say with certainty that the NNT is at least 4.
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This question is part of the following fields:
- Epidemiology And Statistics
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Question 7
Correct
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A 7-year-old girl was brought to the hospital with complaints of fever. 5 days ago, she was taken to her GP with lower abdominal pain and leukocytes 3+ on urine dipstick. She was treated with trimethoprim. On examination, she is found to have a low-grade pyrexia, a CRP of 254 mg/L, and a palpable mass in the right iliac fossa. She is able to consume both solids and liquids. Based on the clinical scenario, what is the probable diagnosis and most appropriate management for this child?
Your Answer: This is an appendix mass and intravenous antibiotics where observation is the initial treatment
Explanation:The most appropriate diagnosis for this patient is appendicular mass. The initial treatment, according to the Ochsner-Sherren regimen recommended by Hamilton Bailey, would be the initiation of intravenous antibiotics.RationaleThe presentation is highly suggestive of appendicular mass. The correct management is broad-spectrum intravenous antibiotics such as co-amoxiclav and amikacin plus observation. Conservative management is the preferred treatment as surgical exploration at this stage can result in increased morbidity.The child should be allowed to eat and drink. If there are on-going temperature spikes, signs of obstruction or severe colicky abdominal pain, then surgery is required. The majority of patients respond to conservative management.Other options:- This is a partially treated appendicitis which has formed an appendix mass. Rather than planning appendectomy immediately; Hamilton Bailey recommended interval appendectomy after 6 weeks post-discharge. However, the need for interval appendectomy is still under debate.- Drainage via interventional radiology is not recommended in this patient as it can lead to swinging pyrexia secondary to peritonitis secondary to the collection.- The patient would have high-grade pyrexia and be constitutionally unwell if the patient was a patient of pyelonephritis. The presentation of the patient is more suggestive of appendicular mass.- The history would be more extended with symptoms of weight loss and altered bowel habit if the patient had Crohn’s disease.
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This question is part of the following fields:
- Paediatric Surgery
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Question 8
Correct
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Oligohydramnios is characterized by which of the given clinical facts?
Your Answer: There is a higher incidence of chorioamnionitis
Explanation: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. It also leads to multiple complications, out of which the incidence of chorioamnionitis is very high. Other complications include fetal growth retardation, limb contractures, GI atresia, and even fetal death.
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This question is part of the following fields:
- Neonatology
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Question 9
Correct
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Which of the following neonatal skin conditions is NOT benign?
Your Answer: Midline lumbosacral lipoma
Explanation:A lumbosacral lipoma is a form of congenital spinal lipoma and can be regarded as a cutaneous marker of dysraphism. It is not a skin condition but rather represents a defect in the process of neurulation and leads to a constellation of other abnormalities. The most common other systemic abnormalities associated with midline lumbosacral lipoma include complex anorectal and urological malformations. Other mentioned conditions are benign rashes or birthmarks.
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This question is part of the following fields:
- Neonatology
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Question 10
Incorrect
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A 9 year old boy with central cyanosis underwent cardiac catheterization. His study results were:Right atrium: 7 mmHg, Saturation 60 %Right ventricle: 110/6 mmHg, Saturation 55 %Pulmonary artery: 20/5 mmHg, Saturation 55 %Left atrium (mean): 9 mmHg, Saturation 98 %Left ventricle: 110/80 mmHg, Saturation 87 %Aorta: 110/80 mmHg, Saturation 76 %.Which the following abnormalities are present in this patient?
Your Answer: Ventricular septal defect
Correct Answer: Pulmonary stenosis
Explanation:The overall diagnosis is Fallot’s tetralogy. Ventricular septal defect with left to right shunt is indicated by drop of oxygen saturation from left atrium to left ventricle. Pulmonary stenosis is indicated by the pressure difference between the pulmonary artery and the right atrium. There is oxygen saturation drop from the left ventricle to the aorta which can be due to the overriding aorta.
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This question is part of the following fields:
- Cardiovascular
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Question 11
Correct
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A 17-year-old boy, who had developed shortness of breath and a loss of appetite over the last month, was referred to a haematologist because he presented with easy bruising and petechiae. His prothrombin time, platelet count, partial thromboplastin and bleeding time were all normal. Which of the following would explain the presence of the petechiae and easy bruising tendency?
Your Answer: Scurvy
Explanation:Scurvy is a condition caused by a dietary deficiency of vitamin C, also known as ascorbic acid. Humans are unable to synthesize vitamin C, therefore the quantity of it that the body needs has to come from the diet. The presence of an adequate quantity of vitamin C is required for normal collagen synthesis. In scurvy bleeding tendency is due to capillary fragility and not coagulation defects, therefore blood tests are normal.
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This question is part of the following fields:
- Nutrition
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Question 12
Correct
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Which of the following vaccinations is contraindicated in patients with malignancy undergoing chemotherapy?
Your Answer: Rubella
Explanation:MMR vaccine is a live vaccine. It contains measles, mumps and rubella. These vaccines should be avoided during chemotherapy and for 6 months after.
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This question is part of the following fields:
- Pharmacology
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Question 13
Correct
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A 10-year-old boy presents with bilaterally enlarged parotid glands for more than 9 months. On examination, both parotid glands are firm and non-tender and are not warm to touch.What is the most probable infectious cause for chronic parotitis in the given scenario?
Your Answer: Human immunodeficiency virus (HIV)
Explanation:The most probable cause for chronic parotitis in this patient would be HIV infection.Rationale:Chronic infectious parotitis is relatively uncommon in children. While mycobacterial infection can result in chronic parotitis, HIV is a relatively more common cause. The presentation should always prompt an HIV test. Other options:- While mumps is the most common cause of acute viral parotitis, the chronic nature of the boy’s presentation rules it out. – Acute bacterial parotitis is usually unilateral and is warm and tender to touch.
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This question is part of the following fields:
- HIV
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Question 14
Correct
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A 1 day old premature baby boy is observed to be hypotonic and unresponsive. He was born by emergency caesarean section. Which of the following is most likely the cause?
Your Answer: Intraventricular haemorrhage
Explanation: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.
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This question is part of the following fields:
- Paediatric Surgery
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Question 15
Incorrect
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Which of the given conditions is an X-linked recessive disease?
Your Answer: Wilson's disease
Correct Answer: Hunter's syndrome
Explanation:Hereditary diseases follow specific inheritance patterns according to the type of gene involved. Mutations in the genes which are on the sex chromosome, chromosome X are called X-linked diseases. X-linked recessive conditions result when both the copies of X-chromosomes are defective, which happens in the case of females since males have only one X- chromosome. Thus, these conditions are more common among males, and examples include colour blindness, haemophilia, Lesch-Nyhan syndrome, and hunter’s syndrome, etc. Hunter’s syndrome is a type of lysosomal storage disease which is also known as mucopolysaccharidosis II. Vitamin D resistant rickets is a X-linked dominant disease. Neurofibromatosis type 1 and 2 are autosomal dominant conditions while Wilson’s disease is autosomal recessive.
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This question is part of the following fields:
- Genetics And Dysmorphology
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Question 16
Incorrect
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Which of the following conditions does not commonly cause a Trendelenburg gait pattern?
Your Answer: Slipped upper femoral epiphysis
Correct Answer: Juvenile idiopathic arthritis
Explanation:Trendelenburg gait is an abnormal gait resulting from a defective hip abductor mechanism. The primary musculature involved is the gluteal musculature, including the gluteus medius and gluteus minimus muscles. The weakness of these muscles causes drooping of the pelvis to the contralateral side while walking.Any pathology of the fulcrum, load, effort or the lever which binds all three will lead to a positive Trendelenburg gait.Failure of the fulcrum presents in the following conditions:Osteonecrosis of hipLegg-Calve-Perthes diseaseDevelopmental dysplasia of the hipChronically dislocated hips secondary to traumaChronically dislocated hips secondary to infections like tuberculosis of the hipFailure of the lever is a feature in the following conditions:Greater trochanteric avulsionNon-union of the neck of the femurCoxa VaraFailure of effort presents in the following conditions:PoliomyelitisL5 radiculopathySuperior gluteal nerve damageGluteus medius and minimus tendinitisGluteus medius and minimus abscessPost total hip arthroplastyThe gait of Juvenile idiopathic arthritis patients can be explained as a crouch-like gait with hyperflexion in hip and knee joints and less plantar flexion in the ankle
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This question is part of the following fields:
- Musculoskeletal
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Question 17
Incorrect
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A 16-year-old boy presents to the emergency department with abdominal pain, fever, and vomiting. On examination, palpation of the left lower quadrant of the abdomen elicits pain in the right lower quadrant. What is this sign?
Your Answer: Murphy's sign
Correct Answer: Rovsing's sign
Explanation:Based on the findings presented, the sign elicited is Rovsing’s sign.Rovsing’s sign:It is a sign suggestive of appendicitis. A positive sign is determined when palpation in the left lower quadrant of a patient’s abdomen causes pain in the right lower quadrant.Other options:- Murphy’s sign is positive in gallbladder inflammation. With the upper border of the examiner’s hand in the right upper quadrant of the abdomen under the rib cage, the patient is asked to inhale. Inhalation causes the gallbladder to descend, which catches on the fingers, causing pain.- Cullen’s sign is suggestive of ectopic pregnancy or acute pancreatitis and describes the bruising around the umbilicus.- Tinel’s sign is positive in those with carpal tunnel syndrome. The examiner’s fingers tap the median nerve over the flexor retinaculum, which causes paraesthesia over the distribution of the median nerve.- Battles’ sign describes bruising behind the ear, suggesting a basal skull fracture of the posterior cranial fossa.
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This question is part of the following fields:
- Emergency Medicine
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Question 18
Correct
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An 8 year old male child of Afro-Caribbean descent complains of acute abdominal pain. Clinical examination reveals a soft abdomen. The boy is tachycardic and has an Hb of 6 g/dl. His mother says she noticed fresh rectal bleeding. What is the most probable diagnosis?
Your Answer: Meckel's Diverticulum
Explanation:Compared to the rest of the options, Meckel’s diverticulum with ectopic gastric mucosa seems to be the most probable diagnosis, as it can lead to fresh bleeding.Fresh red bleeding can be caused by haemorrhoids, polyps or a massive GI bleed.
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This question is part of the following fields:
- Paediatric Surgery
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Question 19
Correct
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A 6-months-old boy develops QT interval prolongation. Which of the following is NOT a cause of QT prolongation in this boy?
Your Answer: Lown-Ganong-Levine syndrome
Explanation:Normal QT interval in a 6 months old baby is < 0.44 seconds. A duration exceeding this value is referred to as QT interval prolongation, which is associated with some important congenital syndromes that include Brugada syndrome which is characterized by vasovagal syncope and sudden cardiac death, Jervell and Lange-Nielsen syndrome which is associated with congenital deafness, Andersen syndrome which is marked by bone deformities, and Timothy syndrome with associated heart disease and immunodeficiency. Romano-Ward syndrome is the commonest cause of congenital QT prolongation with no associated extra-cardiac manifestations. Lown-Ganong-Levine syndrome is characterized by a shortened PR interval and a normal QRS duration.
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This question is part of the following fields:
- Cardiovascular
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Question 20
Correct
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A 6 year old male presented in the OPD with the complaint of nasal bleeding which started 3 days before. Now on examination, there is no bleeding and only slight redness of the anterior mucosa is present. Which of the following steps is the most suitable one now?
Your Answer: Reassurance
Explanation:Epistaxis is common in younger children usually due to nose picking. After the episode is over no active management is required and reassurance should be given to the patient and his attendants.
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This question is part of the following fields:
- ENT
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Question 21
Correct
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An 18-year-old female suffering from acne vulgaris has been started on isotretinoin. Regarding this treatment, which of the following statements is the most applicable?
Your Answer: Pregnancy should be avoided during and 1 month after treatment
Explanation:It is recommended that a woman wait one month after stopping isotretinoin before trying to become pregnant. Usually, isotretinoin is no longer found in a woman’s blood 4-5 days after the last dose and most of its by-products should be gone within 10 days after the last dose.
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This question is part of the following fields:
- Dermatology
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Question 22
Correct
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A 12 year old boy with type I diabetes was reluctant to go to school. According to him, he was unhappy at the school. Which of the following is the next appropriate step?
Your Answer: Clinical psychologist
Explanation:The child’s problem should be assessed properly to find the reason for unhappiness at the school. There can be many reasons such as bullying at school, abuse etc. A clinical psychologist should assess this child to take the necessary details and plan the further management.
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This question is part of the following fields:
- Endocrinology
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Question 23
Incorrect
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What is the average age that puberty starts in boys?
Your Answer: 13 years
Correct Answer: 12 years
Explanation:Puberty is when a child’s body begins to develop and change as they become an adult.The average age for girls to begin puberty is 11, while for boys the average age is 12.It’s completely normal for puberty to begin at any point from the ages of 8 to 14. The process can take up to 4 years.
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This question is part of the following fields:
- Endocrinology
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Question 24
Correct
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Toe walking is NOT a feature of which of the following conditions?
Your Answer: Waardenburg syndrome
Explanation:Toe walking refers to a pattern of walking in which the infants walk on the balls of their feet, without putting the heel of the feet on the ground. It is considered normal under the age of 2 years, but if it continues beyond that, it can signify some underlying pathology. The diseases that can be associated with toe walking include unilateral hip dislocation, Spinal tumours, Duchenne muscular dystrophy, prematurity, and cerebral palsy. Waardenburg’s syndrome is an autosomal dominant disorder, causing sensorineural deafness, and heterochromatic irises. Toe walking is not a feature.
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This question is part of the following fields:
- Child Development
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Question 25
Correct
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A 19-year-old girl presents with polydipsia (>3L daily), polyuria, nocturia, and new-onset nocturnal enuresis. A urine dipstick reveals no glucose or ketones, but her pregnancy test is positive.What is the most probable diagnosis?
Your Answer: Gestational diabetes insipidus
Explanation: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.
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This question is part of the following fields:
- Nephro-urology
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Question 26
Correct
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A 10-year-old gentleman is referred with a six month history of daily headache, which is mostly frontal in location and occasionally associated with nausea.He has been taking paracetamol 3 g daily, aspirin 300 mg thrice daily, and codeine 40 mg thrice daily, all of which have had only a temporary effect. He has a two year history of depression treated with paroxetine. No abnormalities were found on examination.What is the most likely diagnosis?
Your Answer: Analgesic misuse headache
Explanation:Because of the patient’s history of chronic analgesic use of daily paracetamol intake, the most likely diagnosis of this case is Analgesic misuse headache. In these cases, the headache is only temporarily relieved by analgesics. Treatment involves gradual withdrawal of analgesics.
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This question is part of the following fields:
- Neurology
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Question 27
Correct
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Which of the following signs suggests an absence seizure instead of a partial complex seizure?
Your Answer: Induction by hyperventilation
Explanation:Absence seizures are induced by over breathing or hyperventilation, while the other features suggest partial seizures.
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This question is part of the following fields:
- Neurology
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Question 28
Correct
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A 7-year old child from a rural setting complains of recurrent abdominal pain. The child is found to have a heavy parasitic infestation and anaemia. Which type of anaemia is most likely seen in this patient?
Your Answer: Iron deficiency anaemia
Explanation:The most common cause of iron deficiency anaemia in children in developing countries is parasitic infection (hookworm, amoebiasis, schistosomiasis and whipworm).
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This question is part of the following fields:
- Microbiology
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Question 29
Correct
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Which of the following conditions is most likely to permanently impair visual development in a 2-year-old child?
Your Answer: Congenital ptosis
Explanation:A drooping eyelid is called ptosis or blepharoptosis. In ptosis, the upper eyelid falls to a position that is lower than normal. Severe ptosis may cover part or all of the pupil and interfere with vision, resulting in amblyopia.Visual development in a child can be permanently impaired when there is deprivation of visual stimulation or when the oculomotor function is impaired. Congenital ptosis can represent both these components
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This question is part of the following fields:
- Ophthalmology
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Question 30
Correct
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The parents of a 5 year old child with cystic fibrosis present at the clinic with concerns over having another child. Neither of them have cystic fibrosis, and they would like to know what the chances are of their next child being a carrier of the cystic fibrosis gene. What is the probability of this occurring?
Your Answer: 50%
Explanation: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.
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This question is part of the following fields:
- Genetics And Dysmorphology
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