An enlarged lymph node does not necessarily need treatment especially if it is caused by a virus. If it is bacterial, antibiotics should be prescribed. Amoxicillin is first line treatment in non-penicillin allergic patients and side effects include allergic reactions like skin rash and itching

Frequent regurgitation of milk and microcytic anaemia is suggestive of a hiatus hernia. The reflux causes regurgitation of milk and frequent ulceration of the lower oesophageal mucosa potentially resulting in blood loss and anaemia. Duodenal atresia usually presents with bilious vomiting and pyloric stenosis presents with projectile vomiting. Alpha 1 antitrypsin deficiency and cystic fibrosis usually do not present with vomiting.

Undescended testis (UDT) is a common abnormality, affecting about 1/20 males at birth. Half of these have delayed testicular descent, with the testis in the scrotum by 10-12 weeks after term. Beyond this spontaneous descent is rare. Current treatment recommendations are that UDT beyond 3 months need surgery between 6-12 months of age. Some children have scrotal testes in infancy but develop UDT later in childhood because the spermatic cord does not elongate with age, leaving the testis behind as the scrotum moves further from the groin. The maldescended testis suffers heat stress when not at the lower scrotal temperature (33 degrees Celsius), interfering with testicular physiology and development of germ cells into spermatogonia. Recent evidence suggests orchidopexy between 6-12 months improves germ cell development, with early reports of improved fertility, but no evidence yet for changes in malignancy prognosis.Hypospadias is also a common abnormality in new-born males, affecting about 1/150 boys. Androgens control masculinization of the genital tubercle into penis between 8-12 weeks’ gestation, with tabularization of the urethra from the perineum to the tip of the glans. If this process is disrupted hypospadias occurs, with a variable proximal urethral meatus, failed ventral preputial development producing a dorsal hood, and discrepancy in the ventral versus dorsal penile length, causing a ventral bend in the penis, known as chordee. Surgery to correct hypospadias is recommended between 6-18 months.

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 arteriesA 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.

Asthma patients have an increased risk of developing complications like pneumonia or collapsed lung. A clear visualization of the lungs through a CXR will define the management necessary for this patient.

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.

Topical benzoyl peroxide is used for the treatment of mild to moderate acne vulgaris. It is actually a peeling agent and it clears the pores and reduces the bacterial cell count.

Acoustic neuroma/vestibular schwannoma is a benign slow-growing tumour. The clinical picture of the child suggests neurofibromatosis type 1 (NF1), with cafe-au-lait spots and axillary and inguinal freckling.

Breslow thickness is measured from the top of the granular layer of the epidermis (or, if the surface is ulcerated, from the base of the ulcer) to the deepest invasive cell across the broad base of the tumour (dermal/subcutaneous) as described by Breslow.Margins of excision-Related to Breslow thicknessLesions 0-1mm thick – 1cmLesions 1-2mm thick – 1- 2cm (Depending upon site and pathological features)Lesions 2-4mm thick – 2-3 cm (Depending upon site and pathological features)Lesions >4 mm thick – 3cmMarsden J et al Revised UK guidelines for management of Melanoma. Br J Dermatol 2010 163:238-256.

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.