Clinical diagnosis of neurofibromatosis type 1 requires the presence of at least 2 of 7 criteria. Many of these signs do not appear until later childhood or adolescence, and thus confirming the diagnosis often is delayed despite a suspicion of NF1. The 7 clinical criteria used to diagnose NF1 are as follows:- Six or more café-au-lait spots or hyperpigmented macules greater than 5 mm in diameter in prepubertal children and greater than 15 mm in postpubertal- Axillary or inguinal freckles (>2) – Two or more typical neurofibromas or one plexiform neurofibroma- Optic nerve glioma- Two or more iris hamartomas (Lisch nodules), often identified only through slit-lamp examination by an ophthalmologist- Sphenoid dysplasia or typical long-bone abnormalities such as pseudarthrosis- A first-degree relative (e.g., mother, father, sister, brother) with NF1

The age of the patient and the presence of immature white blood cells are suggestive of leukaemia. Hodgkin’s disease is unlikely in this age group and it usually presents with lymphadenopathy. In HIV, immature white blood cells are not present in the blood.

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 diagnosis of scabies can often be made clinically in patients with a pruritic rash and characteristic linear burrows. Definitive testing relies on the identification of mites or their eggs, eggshell fragments, or scybala. This is best undertaken by placing a drop of mineral oil directly over the burrow on the skin and then superficially scraping longitudinally and laterally across the skin with a scalpel blade. (Avoid causing bleeding.) Scraping 15 or more burrows often produces only 1 or 2 eggs or mites, except in a case of crusted scabies, in which many mites will be present. The sample is placed on a microscope slide and examined under low and high power. Potassium hydroxide should not be used, since it can dissolve mite pellets. Failure to find mites is common and does not rule out the diagnosis of scabies.

Hormones can be secreted in a number of different ways, thus plasma levels of each may vary throughout the day. Many of these exhibit intermittent secretion related to sleep (growth hormone, and prolactin), while others are released based on circadian rhythms (cortisol). Some are released in a pulsatile fashion throughout the day such as FSH, LH, Thyroxine, while others are stress related like cortisol.

Membranoproliferative glomerulonephritis primarily affects children and young adults, with patients presenting with nephrotic or nephritic syndrome or with asymptomatic renal disease. There are 3 types defined by pathologic features. All three types are associated with hypocomplementemia, but they manifest somewhat different mechanisms of complement activation. This type of glomerulonephritis often progresses slowly to end-stage renal disease, and it tends to recur after renal transplantation, especially type II.

The child has a history of pharyngitis followed 10 days later by signs of glomerulonephritis. In this particular case, it is most probably a post-streptococcus glomerulonephritis which accounts for 80% of paediatric cases of glomerulonephritis.

The accuracy of the test for calcium levels in the blood is affected by the blood level of albumin. If albumin levels are low, the calcium level can also appear low.This is termed as pseudohypocalcemia.Hypocalcaemia usually presents with muscle spams. These can include spasms of voluntary muscle but also smooth muscle such as in the airways (causing bronchospasm) and in the heart (causing angina).

The most probable diagnosis for this patient is bilateral retractile testes. This a normal phenomenon in some pre-pubertal boys. Rationale:Testicular descent can continue until about 3-months of age. The pre-pubertal testis is small enough that with activation of the cremasteric reflex, they can enter the inguinal canal. This in itself is a normal finding providing the testis can be brought into the scrotum without tension and does not require surgical correction. With time the testis will lie within the scrotum. Orchidopexy for true undescended testis can be performed from 6-months of age. It is also warranted if the testes remain undescended or intra-abdominally leading to infertility.Other options:- An ascending testis is one, typically, following hernia or orchidopexy surgery that was in the testis but with time is within the inguinal canal and cannot be brought into the scrotum. Orchidopexy is required for this.- No surgery is required as when the testis enlarges with puberty it will remain within the scrotum.- The testes can be brought into the scrotum. Therefore they are not undescended.- The testes are retractile not ascending| ascending testis cannot be brought into the scrotum and would require orchidopexy.

Congenital hypothyroidism is associated with failure to thrive, macroglossia, prolonged jaundice of a new-born and constipation.

A vasovagal episode or vasovagal syncope is the most common form of reflex syncope. Reflex syncope is a general term used to describe types of syncope resulting from a failure in autoregulation of blood pressure, and ultimately, in cerebral perfusion pressure resulting in transient loss of consciousness. The mechanisms responsible for this are complex and involve both depression of cardiac output as well as a decrease in vascular tone. Other types of reflex syncope include carotid sinus syncope and situational syncope, for instance, cough or micturition syncope. Vasovagal syncope may be triggered by pain or emotional upset, although frequently a specific trigger cannot be identified.

NICE guidelines suggest that when a child’s single risk factor is 2 vomits, the child should be observed for 4 hours from the time of the injury, instead of having a CT.

Prepubertal atrophic vaginitis is due to a lack of vaginal oestrogen. The pathophysiology behind prepubertal atrophic vaginitis:1.The proximity of the vagina to the anus2.Lack of oestrogen – leads to thinning of the vaginal mucosa3.Lack of pubic hair to protect the area4.Lack of labial fat pads

Logistic regression analysis is an easy to use regression that can serve to estimate how a binary or dichotomous dependent variable, for example whether or not a student passes or fails a medical exam, is related to the number of hours the student studies for the exam. This regression is able to yield an odds ratio, i.e. the probability of passing the exam based on each additional hour of study. As stated, the outcome does not need to be normally distributed but is usually binary. This type of analysis is not complex and does not need to be avoided as it is available most statistical packages.

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.

Lypohypertrophy is the most common skin-related complication of insulin injection.

The external auditory canal (EAC) extends from the auricle to the tympanic membrane. Its lateral portion is fibrocartilaginous and its medial portion is bony. Its bony portion is formed by the tympanic portion of the temporal bone.

The most probable diagnosis for this patient would be Coarctation of Aorta (CoA).Infants with CoA present within the first few weeks of life with signs suggestive of congestive cardiac failure and general circulatory shock. In these patients, the aorta is supplied by the right ventricle, via the ductus arteriosus. Pathophysiology:When the left ventricle supplies the aorta via the aortic isthmus, children are usually asymptomatic or may present with occasional complaints of leg pain. Associated cardiac anomalies are uncommon but for a bicuspid aortic valve, which is present in approximately 50% of cases. Good collateral circulation usually develops in these patients, which in the long term, causes notching of ribs. Clinical Presentation:Clinically, there may be hypertension in the upper limbs (or higher BP readings than in the lower limbs), and leg pulses are absent, or weak and delayed. A systolic click and aortic ejection systolic murmur are heard, caused by the bicuspid aortic valve. Management:The primary medical management is to treat hypertension. After stabilization, the patient can undergo definitive surgical repair. Transcatheter balloon angioplasty of the coarctation is controversial, but ballooning +/- stenting of re-coarctation following surgery is commonly performed.Systemic hypertension may occur following repair, even in the absence of re-coarctation necessitating the re-initiation/continuation of antihypertensive therapy in these patients.

People with Systemic Juvenile Idiopathic Arthritis (also known as Stills disease) can have recurrent fevers, a macular rash, joint pain, joint deformities, an enlarged liver and/or spleen, and can occasionally have polyserositis, lung involvement or pericardial effusions. Rheumatoid factor and antinuclear antibodies are usually negative. Treatment is with non-steroidal anti-inflammatory drugs (NSAIDs) and the prognosis is better than for adult rheumatoid arthritis.In pauciarticular Still’s disease, antinuclear antibodies are present. Large joints are affected and most patients develop classic features of seronegative spondylarthritis.

Nonspecific triggers of inflammation in patients with atopic dermatitis may include physical or chemical irritants. The following simple measures should be followed in daily life to reduce the frequency and severity of irritant-induced atopic dermatitis flares :Skin care products that contain alcohol and astringents should be avoided.New clothes should be laundered before use to remove formaldehyde and other chemicals.Liquid detergents are preferred over powder detergents for laundering clothes, as liquids are easier to rinse out. A second rinse cycle may also improve removal of residual detergent.Patients should shower immediately after swimming in chlorinated pools and should subsequently apply moisturizer.Fragrance-free skin products that are hypoallergenic or made for sensitive skin may be less irritating than other kinds of skin products.Prenatal and postnatal probiotic supplementation may be helpful in preventing the development of atopic dermatitis in young children. In a 2008 meta-analysis, the most commonly studied probiotic was Lactobacillus rhamnoses GG. Larger, randomized controlled studies are needed to confirm these initial findings.Breastfeeding during the first 4 months of life may reduce the incidence and severity of childhood atopic disease but only modestly and only in those at high risk.

Among the options provided, zidovudine causes lipoatrophy as a side effect.Zidovudine: Although both hypertrophy and atrophy are described related to HIV medications, nucleoside reverse transcriptase inhibitor (NRTIs) such as zidovudine and stavudine are closely associated with fat loss.Other options:- Enfuvirtide is an HIV-fusion inhibitor. Lipoatrophy is not commonly associated with this drug.- Efavirenz is an NNRTI, which is not associated with lipoatrophy. Common side effects include neuropsychiatric effects, rash and nausea. – Ganciclovir is not an anti-HIV medication and is used for cytomegalovirus (CMV) infections.- Raltegravir is an integrase inhibitor and is associated with fat gain.

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.

Bernard- Soulier Syndrome results from a deficiency of platelet glycoprotein protein Ib, which mediates the initial interaction of platelets with the subendothelial components via the von Willebrand protein. It is a rare but severe bleeding disorder. Platelets do not aggregate to ristocetin. The platelet count is low, but, characteristically, the platelets are large, often the size of red blood cells, and may be missed on complete blood counts because most automatic counters do not count them as platelets.

The progesterone is primarily responsible for preventing pregnancy. The main mechanism of action is the prevention of ovulation| they inhibit follicular development and prevent ovulation. Progestogen negative feedback works at the hypothalamus to decreases the pulse frequency of gonadotropin-releasing hormone. This, in turn, will decrease the secretion of follicle-stimulating hormone (FSH) and decreases the secretion of luteinizing hormone (LH). If the follicle isn’t developing, then there is no increase in the oestradiol levels (the follicle makes oestradiol). The progestogen negative feedback and lack of oestrogen positive feedback on LH secretion stop the mid-cycle LH surge. With no follicle developed and no LH surge to release the follicle, there is the prevention of ovulation. Oestrogen has some effect with inhibiting follicular development because of its negative feedback on the anterior pituitary with slows FSH secretion| it’s just not as prominent as the progesterone’s effect. Another primary mechanism of action is progesterone’s ability to inhibit sperm from penetrating through the cervix and upper genital tract by making the cervical mucous unfriendly. Progesterone induced endometrial atrophy should deter implantation, but there is no proof that this occurs.

An epidural hematoma occurs when there is bleeding between the dura mater (a tough fibrous layer of tissue between the brain and skull) and the skull bone. These occur when arteries are torn as a result of a blow to the head, and injury in the temple area is a common cause. Although the pattern of a lucid interval followed by later neurological symptoms is characteristic, only a minority of patients display this pattern of symptoms. Reported death rates from epidural hematoma vary widely, ranging from 5% to over 40%. Middle meningeal artery is frequently involved in such incidents.

The autosomal dominant pattern of inheritance involves the presence of at least one of the defected copies of the gene in an individual to develop a specific diseased condition. Examples of this mode of inheritance include myotonic dystrophy, neurofibromatosis, achondroplasia, etc. Still’s disease, also called juvenile idiopathic arthritis, is not a heritable disease. Tay-Sachs disease is an autosomal recessive disease., while spinocerebellar ataxia and Friedreich’s ataxia are caused by trinucleotide repeat expansion.

Pale stools suggest obstructive jaundice. Initially, the symptoms of biliary atresia are indistinguishable from those of neonatal jaundice, a usually harmless condition commonly seen in infants. However, infants with biliary atresia develop progressive conjugated jaundice, pale white stools and dark urine.

Von Hippel-Lindau syndrome is a genetic disorder inherited in autosomal dominant fashion. It is caused by the mutations of the VHL gene located on chromosome 3. The syndrome is characterized by the creation of multiple benign and malignant tumours involving various bodily systems along with the formation of numerous visceral cysts, including the renal and epididymal cysts. Down’s syndrome is associated with renal cysts, but it does not follow the autosomal dominant mode of inheritance, rather it is caused by non-disjunction of chromosome 21 during meiosis. Exomphalos is a defect of the medial abdominal wall leading to abnormal protrusion of abdominal viscera through it. It is not associated with renal cysts. Turner’s syndrome may be associated with renal cysts formation, but it is not transmitted in an autosomal dominant fashion. Polycystic kidney disease of childhood follows an autosomal recessive pattern of transmission.

Physiological jaundice is the condition in which there is a yellow discolouration of the eyes and the skin of the baby caused by the build up of bilirubin in the blood due to an immature liver. No other symptoms accompany physiological jaundice, thus it will not present with difficulty in feeding. All the other conditions listed can present with feeding problems.

The rational part of a teen’s brain isn’t fully developed until the age of 25 or so.In fact, recent research has found that adult and teen brains work differently. Adults think with the prefrontal cortex, the brain’s rational part. This is the part of the brain that responds to situations with good judgment and an awareness of long-term consequences. Teens process information with the amygdala. This is the emotional part.