The study described in the question is a ‘cohort’ study.Other options:A prospective observational study – When groups are classified according to one or more factors at a given time and followed forward to determine outcomes (usually some health status)- Although there is in one sense a control group (those who do not develop the health problem), this is not generally called a ‘controlled’ trial. – An ecological study would look at outcomes in different groups (countries or regions usually) who follow different practices.

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.

Arnold-Chiari malformation type II is one of the congenital hindbrain abnormalities that leads to a disruption of the relationship between different hindbrain structures. It is characterized by congenital hydrocephalus, herniation of cerebellar tonsils into the pinal canal with an enlarged 4th ventricle, spina bifida associated with myelomeningocele, and various levels of denervation atrophy of the muscles of the lower limb. The association of type II Arnold-Chiari with myelomeningocele carries importance from an etiological perspective, forming the basis of CSF escape theory.

Answer: Curling’s ulcersCurling’s ulcer is an acute gastric erosion resulting as a complication from severe burns when reduced plasma volume leads to ischemia and cell necrosis (sloughing) of the gastric mucosa. The most common mode of presentation of stress ulcer is the onset of acute upper GI bleed like hematemesis or melena in a patient with the acute critical illness. A similar condition involving elevated intracranial pressure is known as Cushing’s ulcer. Cushing’s ulcer is a gastro-duodenal ulcer produced by elevated intracranial pressure caused by an intracranial tumour, head injury or other space-occupying lesions. The ulcer, usually single and deep, may involve the oesophagus, stomach, and duodenum. Increased intracranial pressure may affect different areas of the hypothalamic nuclei or brainstem leading to overstimulation of the vagus nerve or paralysis of the sympathetic system. Both of these circumstances increase secretion of gastric acid and the likelihood of ulceration of gastro-duodenal mucosa.Mallory-Weiss syndrome is characterized by upper gastrointestinal bleeding secondary to longitudinal mucosal lacerations (known as Mallory-Weiss tears) at the gastroesophageal junction or gastric cardia. However, Mallory-Weiss syndrome may occur after any event that provokes a sudden rise in the intragastric pressure or gastric prolapse into the oesophagus, including antecedent transoesophageal echocardiography. Precipitating factors include retching, vomiting, straining, hiccupping, coughing, primal scream therapy, blunt abdominal trauma, and cardiopulmonary resuscitation. In a few cases, no apparent precipitating factor can be identified. One study reported that 25% of patients had no identifiable risk factors.

Skin conditions resulting from excessive epidermal proliferation or inflammation, leading to a production of excessive scales, are referred to as papulosquamous disorders. These disorders can be generalized and localized. Localized causes of scaly lesions include tinea corporis, tinea cruris, tinea pedis, seborrheic dermatitis, psoriasis, pityriasis Versicolor, pityriasis alba, DLE, ichthyosis including Netherton syndrome (a severe form of ichthyosis which is autosomal recessive), and pellagra. Generalized causes include guttate psoriasis and pityriasis rosacea. Hand, foot, and mouth disease is a contagious viral illness that causes blisters in the mouth and on the extremities.

Based on the clinical scenario, the most likely risk factor in this child to develop gallstones is sickle cell disease.Note:Haemolysis is the most frequent cause for gallstones in children and the likeliest cause because of his ethnicity would be sickle cell disease. The gallstones are pigmented which form from bilirubin. 70% of patients with sickle cell disease will develop gallstones| the prevalence of gallstones is related to the rate of haemolysis.Other options:- Gilbert’s syndrome: it is a common condition in which bilirubin glucuronidation (i.e. converting bilirubin into a water-soluble form) is affected. During times of stress (viral illness, fasting, etc.) there is an excess bilirubin production, and jaundice may develop. It is a benign condition but there is some evidence of an increased risk of developing gallstones. However, sickle cell disease is a more likely risk factor in this case.- Hereditary spherocytosis: Hereditary spherocytosis is a disease of the white population and is less likely to be the underlying cause in this case.- Male gender: After puberty, the incidence of gallstones is higher in women. Before puberty, the incidence is equal.- Obesity: Obesity is a risk factor for gallstones and is thought to be behind the rising incidence among young adults. Nevertheless, haemolytic states remain the most common reason for gallstones in children.

The combination of frequent infections, eczema, and thrombocytopaenia are characteristic of Wiskott-Aldrich syndrome, which is due to an abnormality in the WASP gene. It is an X-linked recessive disorder that causes primary immunodeficiency owing to a combined B- and T-cell dysfunction.The other listed options are:1. PKD1: polycystic kidney disease2. CFTR: cystic fibrosis3. HFE1: haemochromatosis4. RET: multiple endocrine neoplasia, Hirschsprung’s disease

Intussusception causes abdominal pain leading to painful lower GI bleeding. Intussusception is a condition in which part of the intestine folds into the section next to it. It most commonly involves the small bowel and rarely the large bowel. Intussusception doesn’t usually require surgical correction. 80% of cases can be both confirmed and reduced using barium, water-soluble or air-contrast enema.However, up to 10% of cases can experience recurrence within 24 hours after reduction, warranting close monitoring during this period.Most children have self-limiting and minor bleeds. However, children with massive bleeds will need emergency care and stabilisation.The various causes of lower GI bleeding in neonates include:- Anal fissures- Milk protein or soy allergy- Intussusception- Volvulus- Coagulopathies including haemorrhagic disease of the new-born- Arteriovenous malformations- Necrotising enterocolitis- Hirschsprung enterocolitis- Meckel’s diverticulitis- Drugs (NSAIDs, heparin, indomethacin used for patent duct closure, dexamethasone)The various causes of lower GI bleeding in children aged between 1 month to 2 years include:- Infection- Anal fissures- Intussusception- Malrotation with volvulus- Milk protein or soy allergy- Polyp- Meckel’s diverticulum- Duplication cyst- Foreign body- AV malformation- Colitis of immune deficiency- Tumour- HaematomaThe causes of lower GI bleeding in children older than 2 years include:- Polyp- Inflammatory bowel disease (IBD)- Infectious diarrhoea (caused by Escherichia coli and Shigella)- Intussusception- Haemangiomas- Arteriovenous malformations- Vasculitis- Tumour

Infections of the superficial skin around the eyes are called periorbital, or preseptal, cellulitis. It is predominantly a paediatric disease. Erysipelas is a bacterial skin infection involving the upper dermis which extends into the superficial cutaneous lymphatics. Sinusitis is in sinuses. Orbital infections and conjunctivitis are within the eye.

Erythema nodosum (EN) is an acute, nodular, erythematous eruption that usually is limited to the extensor aspects of the lower legs. It is a delayed hypersensitivity reaction to a variety of antigens| circulating immune complexes have not been found in idiopathic or uncomplicated cases but may be demonstrated in patients with inflammatory bowel disease.Currently, the most common cause of erythema nodosum is a streptococcal infection in children and streptococcal infection and sarcoidosis in adultsIn most patients, erythema nodosum is a self-limited disease and requires only symptomatic relief using nonsteroidal anti-inflammatory drugs (NSAIDs), cool wet compresses, elevation, and bed rest.

Pulmonary surfactant is a mixture of lipids and proteins which is secreted by the epithelial type II cells into the alveolar space.

ADH primarily acts on the collecting ducts.Other options:- The juxtaglomerular apparatus is the site of renin production.- The proximal tubule conducts isosmotic reabsorption of about 60% of sodium chloride and volume. Most of the glucose, amino acids, potassium and phosphate are absorbed here.- The loop of Henle is the site of 25% of sodium reabsorption. Active Chloride transport provides the basis for the counter current multiplier aiding urinary concentration.- The distal convoluted tubule is impermeable to water and acts via active sodium chloride absorption to dilute urine.

The percentages of body water contained in various fluid compartments add up to total body water (TBW). This water makes up a significant fraction of the human body, both by weight and by volume. Ensuring the right amount of body water is part of fluid balance, an aspect of homeostasis. The extracellular fluid (ECF) includes all fluids outside the cells. This fluid can be divided into three fluid departments: interstitial (in the tissue spaces) fluid, blood plasma and lymph, and specialised compartments called transcellular fluid. The extracellular fluid surrounds all the cells in the body and is in equilibrium with the intracellular fluid. So, its composition must remain fairly constant even though substances are passing into and out of the cells. The interstitial fluid, though called a fluid, is in a reality a gel-like composition made up of: water, proteoglycan molecules and collagen. The extracellular fluid constitutes 40% of total body water, with intracellular fluid making up the remaining 60%. It is relatively rich in glucose.

The clinical presentation and leucocytes on the urine dipstick is suggestive of a urinary tract infection. To confirm the diagnosis, urine should be sent for culture and sensitivity.

The patient has hyperprolactinaemia with otherwise normal oestradiol, FSH and LH. This is highly suggestive of Prolactinoma rather than a non functioning tumour.In polycystic ovaries, there is increase in the level of LH while FSH is normal or low.

Prednisone is used for the treatment of myasthenia gravis if there is no initial response to the anticholinesterase medications. Pyridostigmine can make the symptoms of myasthenia gravis worse if used  in the initial stages of treatment. 

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.

The child has experienced the Somogyi phenomenon. It is a phenomenon where there’s a morning rise in blood sugar. Often it occurs as posthypoglycemic hyperglycaemia and follows nocturnal hypoglycaemia. The mechanism is the production of counter-regulatory hormones like glucagon, cortisol and adrenaline, which increase glucose. She can be managed by reducing her evening insulin dosage and increasing complex carbohydrates for supper (evening meal).Type I diabetes mellitus:It is a chronic illness that is characterised by the inability to produce insulin. It is caused by autoimmune destruction of the beta cells in the pancreas and often presents with ketoacidosis.The patient can present with symptoms suggestive of polyuria, polydipsia, and weight loss. There can be periods of islet cell regeneration in these patients, which leads to a ‘honeymoon period’ of remission.Symptoms occur when there is < 20% of islet cell activity left.Insulin therapy is required in almost all children with type 1 diabetes.Most children require multiple insulin injections throughout the day via subcutaneous insulin pumps.Target HbA1c in these patients is 48 mmol/mol according to the updated NICE guidelines.

By 15 months, it’s common for many toddlers to:- say three to five words.- understand and follow simple commands.- point to one body part.- walk alone and begin to run.- climb on furniture.- make marks with a crayon.- imitate activities, such as housework.

A consultation with an ENT is required to establish the reason for the child’s drooling and stridor indicating and obstructive process. Enlarged tonsils and adenoids should be checked.