Paediatric Medicine: Malaria, Pubertal Disorders, Neonatal Respiratory Distress, and Abdominal Pain

Vocabulary practice flashcards covering malaria pathogenesis, complications, pubertal staging, precocious and delayed puberty, neonatal respiratory distress, and paediatric abdominal pain based on lecture notes.

Plasmodium falciparum

The protozoan parasite that causes human malaria and serves as the commonest species in Africa, accounting for more than 90% of cases and the vast majority of severe complications.

Life Cycle of the Malaria Parasite

The complex life cycle of Plasmodium consisting of an asexual cycle in humans (sporozoite invasion of hepatocytes, tissue schizogony, followed by merozoite invasion and replication within erythrocytes) and a sexual cycle in the female Anopheles mosquito (gametocyte fertilization forming an ookinete, oocyst, and sporozoites).

Hypnozoites

Dormant liver forms produced during infections with Plasmodium vivax and Plasmodium ovale that can hibernate in hepatocytes and cause clinical relapses months or years later.

Rapid Diagnostic Test (RDT)

An immunochromatographic diagnostic tool that detects specific parasite antigens and proteins in whole blood, providing rapid parasitological confirmation of malaria without microscopic examination.

Hyperparasitaemia

A major laboratory feature of severe malaria defined by a peripheral parasite density $>250{,}000/\text{UL}$ of blood or $\ge 5\%$ parasitized red blood cells.

Intravenous Artesunate

The WHO-recommended first-line parenteral antimalarial for severe malaria, administered at $3.0\,\text{mg/kg}$ per dose for children $<20\,\text{kg}$ and $2.4\,\text{mg/kg}$ per dose for children $>20\,\text{kg}$ at 0, 12, and 24 hours, followed by once daily until oral artemisinin-based combination therapy can be tolerated.

Cerebral Malaria

A severe, rapidly progressive encephalopathy of Plasmodium falciparum malaria characterized by plugging of cerebral microvasculature, unarousable coma (Glasgow Coma Scale $<11$ or Blantyre Coma Scale $<3$) persisting for $>30$ minutes, confirmation of asexual parasites, and exclusion of alternative encephalopathies.

Hypothalamic-Pituitary-Gonadal (HPG) Axis

The hormonal regulatory system that initiates and regulates puberty; kisspeptin triggers pulsatile GnRH release from the hypothalamus, which stimulates anterior pituitary secretion of LH and FSH to drive gonadal sex steroid production and gametogenesis.

Adrenarche

The physiological maturation and activation of the adrenal zona reticularis, leading to increased secretion of adrenal androgens.

Thelarche

The onset of female breast development stimulated by ovarian estrogens, representing the first physical sign of puberty in girls.

Orchidometer

A string of numbered ellipsoidal wooden or plastic beads of graded volumes used in clinical practice to measure testicular size and assess pubertal staging in boys.

Tanner Staging of Breast Development

A five-stage classification of female secondary sexual characteristics from Stage 1 (preadolescent juvenile breast) through Stage 2 (breast bud), Stage 3 (enlargement without contour separation), Stage 4 (areola and papilla forming a secondary mound), to Stage 5 (mature adult breast).

Tanner Stage G2

The defining clinical sign of pubertal onset in boys, characterized by testicular enlargement to a volume of $4\text{ to }8\,\text{mL}$ via orchidometer, with scrotal thinning, reddening, and enlargement, while penile length remains essentially unchanged.

Precocious Puberty

The appearance of two or more secondary sexual characteristics before age 8 years in girls or before age 9 years in boys, resulting from early maturation of the hypothalamic-pituitary-gonadal axis or peripheral steroid oversecretion.

Delayed Puberty

The clinical absence of secondary sexual characteristics by age 13 years in females (no breast bud) or by age 14 years in males (no testicular enlargement), or the failure of pubertal progression within 5 years of commencement.

Constitutional Delay of Growth and Development (CDGD)

A normal physiological variant and the most common cause of delayed puberty, marked by delayed pubertal onset and growth spurt with normal adult reproductive potential, frequently accompanied by a positive family history in 50% to 75% of cases.

Transient Tachypnea of the Newborn (TTN)

A common cause of neonatal respiratory distress resulting from delayed clearance of fetal alveolar fluid through amiloride-sensitive sodium channels, characteristically presenting within 2 hours of birth with tachypnea ($\ge 60\,\text{breaths/min}$) and perihilar linear streaking on chest radiography.

Respiratory Distress Syndrome (RDS)

A pulmonary disorder primarily affecting preterm neonates caused by a deficiency of pulmonary surfactant (predominantly desaturated palmitoyl phosphatidyl choline), producing diffuse atelectasis and a characteristic ground-glass reticulogranular pattern with air bronchograms on chest radiograph.

Persistent Pulmonary Hypertension of the Newborn (PPHN)

A syndrome characterized by sustained elevated pulmonary vascular resistance after delivery that forces right-to-left shunting of deoxygenated blood through the patent ductus arteriosus and foramen ovale, leading to profound hypoxemia.

Differential Pre- and Post-ductal Oxygen Saturation

A diagnostic finding in PPHN defined by a pulse oximetry difference of $>10\%$ between the pre-ductal site (right upper extremity) and the post-ductal site (lower extremities) due to right-to-left ductal shunting.

Abdominal Clinical Regions

A standard topographical division of the abdomen into nine distinct regions (epigastric, umbilical, hypogastric, bilateral hypochondriac, bilateral lumbar, and bilateral iliac) to pinpoint tenderness and assist in diagnosing acute abdominal pathology.

Functional Abdominal Pain (FAP)

A recurrent disorder of gut-brain interaction characterized by episodic or continuous periumbilical pain occurring at least 4 times per month, not solely related to physiological events, with no identifiable organic or structural abnormality.

Infantile Colics

A benign, self-limiting behavioral syndrome in well-fed infants characterized by paroxysmal, inconsolable crying conforming to Wessel's rule of 3s ($\ge 3\,\text{hours/day}$, $\ge 3\,\text{days/week}$, for $\ge 3\,\text{weeks}$), resolving spontaneously by 3 to 6 months of age.

Acute Abdomen

A clinical syndrome characterized by sudden-onset, severe abdominal pain that constitutes a medical emergency, frequently featuring involuntary guarding, rebound tenderness, and peritonitis, often requiring urgent surgical evaluation.

Rebound Tenderness

A clinical physical exam sign indicating peritonitis in which the patient experiences significantly greater pain upon the sudden release of manually applied abdominal pressure than upon its application.