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.

Distal renal tubular acidosis (dRTA) is characterised by a decreased hydrogen ion excretion from the alpha intercalated cells of the collecting duct of the distal nephron. The resultant acidosis causes Ca and phosphates to be released from bones to buffer the acidosis causing hypercalciuria, thus precipitating calcium compounds in the kidney. Other consequences of the dRTA in children include rickets, hypokalaemia, and polyuria. While dRTA can occur as a result of various pathologies including autoimmune disease, proximal renal tubular acidosis often presents as part of Fanconi’s syndrome. One way to differentiate between the two conditions is with an acid challenge test. In proximal RTA offering the child an acid load will decrease the urinary ph whereas in distal disease the pH will be unaffected due to impairment in hydrogen ion secretion.

Neuroanatomically, the frontal lobe is the largest lobe of the brain lying in front of the central sulcus. It is divided into 3 major areas defined by their anatomy and function. They are the primary motor cortex, the supplemental and premotor cortex, and the prefrontal cortex. Damage to the primary motor, supplemental motor, and premotor areas lead to weakness and impaired execution of motor tasks of the contralateral side. The inferolateral areas of the dominant hemisphere are the expressive language area (Broca area, Brodmann areas 44 and 45), to which damage will result in a non-fluent expressive type of aphasia.

Cranial nerve II (CN II or optic nerve) runs along the midline of the ventral surface of the brain and conveys visual information from the retina of each eye to the corresponding region of the primary visual cortex. The right half of the visual field of both eyes is processed by the left half of the retina, while the right half of the retina processes the left half of the visual field. These retinal ganglion cells project myelinated axons, carrying CN II sensory afferent fibres, through the optic chiasm, where optic nerve fibres from the nasal half of each retina decussate to the contralateral side of the brain for processing. After passing through the optic chiasm, the optic nerve becomes the optic tract that synapses to the lateral geniculate nucleus (LGN) of the thalamus and subsequently projects optic radiations to the primary visual cortex (V1) of the occipital lobe. The optic tract also projects to the superior colliculus, pretectal nuclei, and suprachiasmatic nuclei. This part of the optic pathway serves the important light reflex.

Due to the anatomical location of the optic chiasm superior to the pituitary gland, a suprasellar extension of a pituitary macroadenoma will lead to compression of the optic nerve fibres decussating at the optic chiasm. Impingement of these nerves prevents visual information from the temporal visual fields of each eye from reaching the processing centres in the brain, leading to peripheral vision loss

Insertion sites and sensor sites should be rotated each time the infusion set or glucose sensor is changed. This keeps the tissue healthy and allows previous sites to completely heal before reusing them. Change infusion set every 2 to 3 days to help prevent infection.

Ichthyosis vulgaris presents clinically with xerosis, hyperkeratosis, excess scaling, keratosis pilaris, and palmar and plantar hyperlinearity. It most commonly affects the extensor surfaces of the limbs and spares flexor surfaces, the face, and the neck.

The sensitivity of a screening test can be described in a variety of ways, typically such as sensitivity being the ability of a screening test to detect a true positive, being based on the true positive rate, reflecting a test’s ability to correctly identify all people who have a condition, or, if 100%, identifying all people with a condition of interest by those people testing positive on the test.

The specificity of a test is defined in a variety of ways, typically such as specificity is the ability of a screening test to detect a true negative, being based on the true negative rate, correctly identifying people who do not have a condition, or, if 100%, identifying all patients who do not have the condition of interest by those people testing negative on the test.

Sensitivity=[a/(a+c)]x100
Specificity=[d/(b+d)]x100
a: True positive
b: False Positive
c: False negative
d: True negative

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.

90% of patients with meconium ileus have cystic fibrosis (CF). Indeed, in 10 – 15% of cases of CF, the patient presents with meconium ileus.

Hyposplenism is associated with thrombocytosis.
Other features of hyposplenism are:
– Howell-Jolly bodies and acanthocytosis, occurring secondary to haemolysis.
– Pappenheimer bodies: These are granular deposits of iron found within the RBCs.
– Lymphocytosis and monocytosis.
Causes for hyposplenism include:
– Congenital asplenia
– Iatrogenic splenectomy: Following trauma or treatment for ITP, thalassemia or spherocytosis).
– Autosplenectomy: Secondary to sickle cell anaemia, coeliac disease, dermatitis herpetiformis, essential thrombocythemia or splenic arterial thrombosis).

The first brachial arch (mandibular) gives rise to the mandibular and maxillary processes. Muscles and bones of this process originate within the arch’s mesoderm. The first arch cartilage (Meckel’s) ossifies to form the incus and malleus of the middle ear. Its perichondrium gives rise to he sphenomandibular ligament and through intermembraneous ossification after the mandible forms, the rest of the cartilage disappears. Muscles of the first arch include: mylohyoid, tensor tympany and palati, temporalis, masseter and lateral pterygoids and the anterior belly of the epigastric. This first arch is supplied by the trigeminal nerve.

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.

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. It produces an itchy rash with a central area of clearance surrounded by raised scaly borders. Diagnosis can be made by skin examination. All other mentioned conditions do not affect the palms and soles.

Blood tests do not help in the diagnosis of jaundice except of course by telling the level of jaundice (bilirubin) and providing some corroborative evidence such as autoantibodies, tumour markers or viral titres in the case of hepatitis. Classifying causes of jaundice on the basis of ultrasound provides a quick and easy schema for diagnosing jaundice which is applicable in primary care as well as hospital based practice.

Eczema is an immune-mediated inflammatory condition of the skin characterized by intense pruritis and scaly rashes over the body. The impact of the disease can be measured by using certain scales, which include the Dermatitis Family Impact (DFI) Questionnaire, infant’s Dermatitis Quality of Life Index, Patient-oriented Eczema Measure, and Children’s Dermatology Life Quality Index among many others. Eczema severity questionnaire is not a recognized scale to determine eczema impact.

The most probable cause for the patient’s presentation would be intra-abdominal adhesions, and the most appropriate management for this patient would be nasogastric decompression and intravenous fluids.

Malrotation typically presents in the first month of life with bilious vomiting. There is a lifetime risk of intra-abdominal adhesions. This presents with bilious vomiting and dilated bowel loops on plain abdominal film. 2/3 of adhesional obstructions resolve by conservative management with nasogastric decompression and intravenous fluids. If this fails to resolve after 24-48 hours or if there are signs of peritonism, a laparotomy is indicated.

Other options:
– Recurrent volvulus, urgent laparotomy required: The child is now 8-years-old and recurrent volvulus is unlikely as bowel should be fixed by intra-abdominal adhesions.
– Intra-abdominal adhesions, surgery for division of intra-abdominal adhesions: Although surgery may be required, the majority of adhesional obstructive cases respond to conservative management.
– Gastroenteritis with incompetent pylorus, intravenous fluids:
While it is true that patients with malrotation can have bilious vomiting in gastroenteritis, the abdominal X-ray is suggestive of obstruction.
– Likely sepsis with bilious vomiting, intravenous fluids and antibiotics: While a septic ileus can give bilious vomiting, this patient has no inflammatory markers suggestive of sepsis.

Among the options provided, an 8-week-old full-term infant with normal developmental milestones will smile in response to appropriate stimuli.

Rationale:
Smiles in response to appropriate stimuli are seen from around 6 weeks of age. A social smile, where the infant has an awareness that a smile attracts attention, is not observed until around 3 months of age.

Other options:
– At 6 weeks an infant is able to follow objects in the horizontal plane through 90 deg; fixing and following an object through 180 deg in the horizontal plane is a milestone achieved at 3 months, as is pushing up onto forearms.
– Pushing up onto hands occurs by around 5 months.
– Infants of 3 months should startle to a 60 dB sound.

Treating persons infected with C. trachomatis prevents adverse reproductive health complications and continued sexual transmission, and treating their sex partners can prevent reinfection and infection of other partners. Treating pregnant women usually prevents transmission of C. trachomatis to neonates during birth. Chlamydia treatment should be provided promptly for all persons testing positive for infection; treatment delays have been associated with complications (e.g., PID) in a limited proportion of women. To minimize disease transmission to sex partners, persons treated for chlamydia should be instructed to abstain from sexual intercourse for 7 days after single-dose therapy or until completion of a 7-day regimen and resolution of symptoms if present. To minimize risk for reinfection, patients also should be instructed to abstain from sexual intercourse until all of their sex partners are treated. Persons who receive a diagnosis of chlamydia should be tested for HIV, GC, and syphilis.

Congenital LQTS arises from mutations in genes that code for ion channels within myocytes.
These mutations all cause ventricular action potentials to be prolonged, resulting in a lengthened QT interval on ECG. The congenital long-QT syndrome (LQTS) is a life-threatening cardiac arrhythmia syndrome that represents a leading cause of sudden death in the young. LQTS is typically characterized by a prolongation of the QT interval on the ECG and by the occurrence of syncope or cardiac arrest, mainly precipitated by emotional or physical stress.
LQTS type 1:
– Most common type of congenital LQTS
– Defect: loss of function mutation on the KCNQ1 gene located on chromosome 11p – defective slow delayed rectifier voltage-gated potassium channel
Subtypes:
Jervell and Lange-Nielsen syndrome: Associated with congenital deafness,, autosomal recessive, associated with ventricular tachyarrhythmias
Romano-Ward syndrome: No associated deafness, autosomal dominant, associated with ventricular tachyarrhythmias

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.

The most common position of the appendix is the retrocecal position.

Note: If a retrocecal appendix is difficult to remove, then mobilisation of the right colon significantly improves access.

Other options:
The various positions of the appendix are:
– Retrocecal (74%)
– Pelvic (21%)
– Postileal
– Subcaecal
– Paracaecal
– Preileal

Immunoglobulin G (IgG) glomerular immune deposits are seen more commonly in HSP compared to IgA nephropathy.
The presentation of the child is highly suggestive of Henoch-Schonlein purpura (HSP).
It is an IgA-mediated, autoimmune hypersensitivity vasculitis that targets the small vessels of the skin, GI tract, kidneys, and joints.
It is most commonly seen in children aged 3 – 6years and is twice as common in boys than girls.
Preceding viral URTI with low-grade pyrexia is common. The most common organism associated with HSP is, however, Group A streptococcal infection A.
A purpuric rash is seen on the back of the legs and buttocks and can less frequently, affect the arms. Arthralgia is common (usually knees/ankles) in these patients. Abdominal pain and bloody diarrhoea may occur. And half of the children with HSP have renal involvement. Rarely, it can lead to end-stage renal failure.

Treatment includes adequate hydration, occasionally steroids, and other immunosuppressants. The disease can recur in 1 in 3 children.

The origins of the neural tube and the nape of the neck where nuchal translucency measurements are taken are from embryonic ectoderm.
The structural development of the head and neck occurs between the third and eighth weeks of gestation. The 5 pairs of branchial arches, corresponding to the primitive vertebrae gill bars, that form on either side of the pharyngeal foregut on day 22 are the embryologic basis of all the differentiated structures of the head and neck. Each arch consists of 3 layers: an outer covering of ectoderm, an inner covering of endoderm, and a middle core of mesenchyme. These arches are separated further into external, ectoderm-lined pharyngeal clefts and internal, endoderm-lined pharyngeal pouches

A population of ectodermal cells adjacent to the neural fold and not included in the overlying surface (somatic) ectoderm gives rise to the formation of the neural crest. These neuroectodermal crest cells are believed to migrate widely throughout the developing embryo in a relatively cell-free enriched extracellular matrix and differentiate into a wide array of cell and tissue types, influenced by the local environment. Most connective and skeletal tissues of the cranium and face ultimately come from the derivatives of neural crest cells.

The ductus arteriosus is normally patent during fetal life; it is an important structure in fetal development as it contributes to the flow of blood to the rest of the fetal organs and structure. From the 6th week of fetal life onwards, the ductus is responsible for most of the right ventricular outflow, and it contributes to 60% of the total cardiac output throughout fetal life. Only about 5-10% of its outflow passes through the lungs.
This patency is promoted by continual production of prostaglandin E2 (PGE2) by the ductus.
In the foetus, the oxygen tension is relatively low, because the pulmonary system is non-functional. Coupled with high levels of circulating prostaglandins, this acts to keep the ductus open. The high levels of prostaglandins result from the little amount of pulmonary circulation and the high levels of production in the placenta.
At birth, the placenta is removed, eliminating a major source of prostaglandin production, and the lungs expand, activating the organ in which most prostaglandins are metabolized. In addition, with the onset of normal respiration, oxygen tension in the blood markedly increases. Pulmonary vascular resistance decreases with this activity.
Normally, functional closure of the ductus arteriosus occurs by about 15 hours of life in healthy infants born at term. This occurs by abrupt contraction of the muscular wall of the ductus arteriosus, which is associated with increases in the partial pressure of oxygen (PO2) coincident with the first breath. A preferential shift of blood flow occurs; the blood moves away from the ductus and directly from the right ventricle into the lungs. Until functional closure is complete and PVR is lower than SVR, some residual left-to-right flow occurs from the aorta through the ductus and into the pulmonary arteries
A balance of factors that cause relaxation and contraction determine the vascular tone of the ductus. Major factors causing relaxation are the high prostaglandin levels, hypoxemia, and nitric oxide production in the ductus. Factors resulting in contraction include decreased prostaglandin levels, increased PO2, increased endothelin-1, norepinephrine, acetylcholine, bradykinin, and decreased PGE receptors. Increased prostaglandin sensitivity, in conjunction with pulmonary immaturity leading to hypoxia, contributes to the increased frequency of patent ductus arteriosus (PDA) in premature neonates.
Although functional closure usually occurs in the first few hours of life, true anatomic closure, in which the ductus loses the ability to reopen, may take several weeks. The second stage of closure related to the fibrous proliferation of the intima is complete in 2-3 weeks.

The average age for girls to begin puberty is 11.
The first sign of puberty in girls is usually that their breasts begin to develop.
It’s normal for breast buds to sometimes be very tender or for one breast to start to develop several months before the other one.
Pubic hair also starts to grow, and some girls may notice more hair on their legs and arms.
After a year or so of puberty beginning, and for the next couple of years:
girls’ breasts continue to grow and become fuller.
Around 2 years after beginning puberty, girls usually have their first period,
pubic hair becomes coarser and curlier
underarm hair begins to grow.
From the time their periods start, girls grow 5 to 7.5cm (2 to 3 inches) annually over the next year or two, then reach their adult height.
After about 4 years of puberty in girls:
breasts become adult-like
pubic hair has spread to the inner thigh
genitals should now be fully developed
girls stop growing taller.

Diarrhoea is defined as having three or more loose or liquid stools per day, or as having more stools than is normal for that person. Severe diarrhoea, causing fluid loss and loss of bicarbonate, will result in marked dehydration and metabolic acidosis.

Management of acute otitis media should begin with adequate analgesia. Antibiotic therapy can be deferred in children two years or older with mild symptoms. Antibiotics should be prescribed immediately if:
– Symptoms lasting more than 4 days or not improving
– Systemically unwell but not requiring admission
– Immunocompromise or high risk of complications secondary to significant heart, lung, kidney, liver, or neuromuscular disease
– Younger than 2 years with bilateral otitis media
– Otitis media with perforation and/or discharge in the cana
High-dose amoxicillin (80 to 90 mg per kg per day) is the antibiotic of choice for treating acute otitis media in patients who are not allergic to penicillin, otherwise erythromycin or clarithromycin should be given.

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.

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.

Hyperthyroidism is the least likely cause of cataract development as all of the other mentioned options can lead to eye problems. Asthma and crohn’s can lead to steroid induced cataract formation, while trauma to the eye can cause traumatic cataracts to develop afterwards. JIA often leads to uveitis.