NEW = {
7: "Iron deficiency is the most common cause of anemia in young children, driven by excessive cow's milk intake in toddlers, prematurity, low dietary iron or chronic blood loss. It produces a microcytic, hypochromic anemia with raised red cell distribution width, low ferritin and low transferrin saturation, and responds to oral iron with dietary counseling and a recheck after several weeks.",
8: "Urinary tract infection is a frequent cause of unexplained fever in infants, who present with irritability, vomiting or poor feeding, while older children describe dysuria, frequency and flank pain. Diagnosis requires both pyuria and a positive culture from an appropriately collected specimen, since bag specimens are unreliable, and antibiotics follow local resistance patterns until sensitivities return.",
247: "Grief is a normal emotional response to loss rather than a disease, and it looks different by age — separation anxiety under 3, regression at 3-5, somatic complaints and school problems at 6-10, and risk-taking or peer withdrawal in adolescents. Duration flags concern beyond 6 months in preschoolers and 3 months in older children, and medication is not first-line.",
249: "Hyperthyroidism in children is caused by Graves disease in about 95% of cases, mainly affecting female adolescents, and presents with tachycardia, tremor, heat intolerance, weight loss and emotional lability. Suppressed TSH with raised free T4 or T3 confirms it, positive TSH-receptor antibodies distinguish Graves from hashitoxicosis, and methimazole is first-line.",
250: "Hypoxic-ischemic encephalopathy is brain injury from inadequate oxygen or blood flow, usually perinatal, affecting roughly 0.5-8 per 1,000 term births in high-income countries and up to 26 per 1,000 elsewhere. Much of the damage occurs during reperfusion rather than the initial insult, which is why therapeutic hypothermia is standard care for moderate-to-severe disease.",
251: "Intimate partner violence is a pattern of physical, sexual and psychological aggression used to establish control, and children are exposed when they see, hear or observe its effects. Exposed children show more depression, anxiety, aggression and developmental delay, and it raises the risk of direct child abuse, so screening belongs at every adolescent health visit.",
257: "Pediatric obesity is a BMI at or above the 95th percentile for age and sex, arising from combined metabolic, genetic, environmental and behavioral factors, with parental obesity a strong predictor. It carries type 2 diabetes, hypertension, dyslipidemia, fatty liver and obstructive sleep apnea, and treatment aims to reduce morbidity through sustained family-based lifestyle change rather than a target weight.",
261: "Pyelonephritis is upper urinary tract infection with renal parenchymal involvement and is the most common bacterial infection in febrile infants under 24 months without an obvious source. Young children present atypically with fever alone or vague abdominal discomfort, so urine is cultured before antibiotics, and treatment runs 7 days with ultrasound to look for anatomic anomalies.",
264: "Respiratory failure is oxygenation or ventilation insufficient for metabolic demand, the end stage of respiratory distress, and infants are predisposed by small compliant airways, fewer alveoli and fatigable muscles. The exam pattern localizes the problem — stridor above the thorax, wheeze within it, grunting and crackles in the alveoli — and formal criteria need two clinical plus one laboratory finding.",
265: "Small for gestational age is a birth weight below the 10th percentile, describing size at birth rather than growth trajectory, and may be symmetric, with length equally reduced, or asymmetric from late placental insufficiency. Between 85 and 90% catch up to their genetic height potential by age 4, though these infants are prone to hypoglycemia from poor glycogen stores.",
272: "Traumatic brain injury accounts for half of trauma-related deaths in US children and over 800,000 emergency visits a year, with falls the most common mechanism under age 4. Primary injury happens at impact and is preventable only by helmets and restraints, while secondary injury from hypoxia, hypotension and hypoglycemia unfolds over days and is what treatment targets.",
275: "Achondroplasia is the most common skeletal dysplasia causing disproportionate [[103|short stature]], affecting roughly 1 in 20,000-30,000 births from a gain-of-function FGFR3 mutation that is usually de novo and rises with paternal age. Intelligence and lifespan are largely normal, but children need active screening for cervicomedullary compression, hydrocephalus, sleep apnea and hearing loss.",
284: "Chronic kidney disease is kidney damage or a GFR below 60 mL/min/1.73m² persisting at least 3 months, staged 1 to 5 by GFR with albuminuria added in 2012 because both independently predict progression. Even mild-to-moderate disease impairs IQ, academic achievement and attention in roughly a third of children, correlating with higher blood pressure and lower GFR.",
292: "Febrile seizure is a seizure with fever in a child of 6 to 60 months without CNS infection or prior afebrile seizure, affecting 2-5% of children and peaking at 12-18 months. About 85% are simple — generalized, under 15 minutes, once in 24 hours — later [[206|epilepsy]] risk is only 1-3%, and lumbar puncture is strongly considered under 12 months.",
294: "Heat illness runs from heat cramps and syncope through heat exhaustion to [[295|heat stroke]], and is among the leading causes of death in US high school athletes. Children are more vulnerable than adults because they generate more heat per kilogram, sweat less and start sweating later, so prevention rests on hydration, gradual acclimatization over 8-12 days and rest breaks.",
296: "Hepatitis C in children is acquired mostly by vertical transmission, which occurs in about 5-6% of pregnancies where the mother is RNA-positive at delivery and doubles or triples with HIV coinfection. Breastfeeding remains safe, the childhood course is indolent, and diagnosis waits until 18 months for maternal antibody to clear before oral direct-acting antivirals from age 12.",
302: "Neonatal intestinal obstruction presents with failure to pass meconium within 24-48 hours, feeding intolerance, distention or vomiting, and the vomiting localizes it — nonbilious above the ampulla of Vater, bilious below, with a scaphoid abdomen proximal and a distended one distal. Over 90% of atresias involve the duodenum, jejunum or ileum, while adhesions dominate in older children.",
308: "Migraine is the most common cause of recurrent headache brought to medical attention in children, peaking at 5-15 years, and differs from the adult pattern in being frequently bilateral and shorter, lasting 1-72 hours. Aura occurs in fewer than half, diagnosis rests on history with a normal examination, and neurologic abnormality or thunderclap onset demands another explanation.",
310: "Nephrotic syndrome is heavy proteinuria with hypoalbuminemia and edema, and minimal change disease causes 85-90% of primary pediatric cases, typically at ages 2-6, with over 80% responding to steroids. It creates a hypercoagulable state and, through urinary immunoglobulin loss, susceptibility to pneumococcal peritonitis and sepsis, and children can be intravascularly depleted despite obvious fluid overload.",
316: "Otitis externa is inflammation of the external auditory canal, usually polymicrobial and led by Pseudomonas aeruginosa in up to 60% of cases, especially in swimmers. Diagnosis needs onset within 48 hours of otalgia, pruritus and fullness plus tenderness on tragal traction, and treatment is topical antibiotic-corticosteroid drops after debridement, with a wick if the canal is too swollen.",
323: "Beckwith-Wiedemann syndrome is an overgrowth and imprinting disorder of chromosome 11p15 affecting about 1 in 14,000 births, with macrosomia, macroglossia, hemihyperplasia, omphalocele and neonatal hypoglycemia from beta-cell hyperplasia. It carries a tumor risk near 7.5%, chiefly Wilms tumor and hepatoblastoma, concentrated before age 8, so surveillance is alpha-fetoprotein and abdominal ultrasound every 3 months.",
334: "Syncope is brief loss of consciousness and postural tone from transient global cerebral hypoperfusion with rapid complete recovery, and 15-25% of children experience it by age 18, peaking in the second decade. Vasovagal syncope accounts for about 80%, but roughly 10% is cardiac, so exercise-induced syncope, absent prodrome or a family history of sudden death demands cardiac evaluation.",
342: "Absence seizures are brief generalized seizures of staring and behavioral arrest lasting 2-20 seconds, with no aura or postictal period, often mistaken for daydreaming or inattention. Childhood absence [[206|epilepsy]] begins at 4-10 years with a 3-Hz spike-and-wave EEG provoked by hyperventilation, and over 90% become seizure-free on ethosuximide, with remission by about age 12.",
346: "Alopecia areata is the most common cause of [[370|hair loss]] in children, a T-cell-driven autoimmune attack on anagen follicles that produces sudden, sharply circumscribed round patches on normal-looking, smooth scalp. Exclamation-point hairs at the patch margin are classic, about half of children regrow completely within a year, and first-line treatment is topical corticosteroids.",
348: "An asthma exacerbation is progressive worsening of breathlessness, cough, wheeze and chest tightness, and as many as 85% in school-age children coincide with viral infection, the single biggest risk factor for hospitalization. Most improve with frequent bronchodilators and systemic corticosteroids, but a prior severe exacerbation best predicts a future fatal one, and most asthma deaths happen at home.",
349: "Anemia is a hemoglobin more than 2 standard deviations below the age- and sex-specific mean, so its definition shifts with age, and it is classified by mean corpuscular volume and by whether production is reduced, destruction increased or blood lost. Gradual anemia is often asymptomatic through compensation, so stabilization should follow the clinical picture rather than the hemoglobin alone.",
354: "Chronic diarrhea is insidious-onset diarrhea lasting more than 2 weeks, distinct from persistent diarrhea, which begins acutely and outlasts 14 days. Toddler's diarrhea explains most cases between 6 months and 5 years in a thriving child, irritable bowel syndrome dominates in adolescents, and waking at night to pass stool points to an organic cause.",
358: "More than 60,000 US children reach the emergency department each year for medication overdose, about 90% after unsupervised ingestion and peaking under age 5. Children are pharmacologically more vulnerable because of immature metabolism and a narrower therapeutic window, and the toxidrome framework — anticholinergic, opioid, sympathomimetic, sedative-hypnotic — links the examination pattern to the drug class.",
359: "Facial palsy is among the most common mononeuropathies in children, about 90% acquired, and Bell palsy accounts for up to half of acquired cases, appearing suddenly about 2 weeks after a viral illness in children over 8. Steroids and acyclovir do not improve recovery, up to 90% recover fully, and bilateral palsy should prompt testing for [[191|Lyme disease]].",
361: "Foreign body ingestion is most common between 6 months and 3 years, with coins the object most often swallowed and up to half of children asymptomatic at presentation. Most objects pass spontaneously and only 10-20% need endoscopy, but an esophageal foreign body risks perforation, and batteries and multiple magnets are the ingestions most likely to kill.",
368: "Neonatal hypocalcemia is a total serum calcium below 8 mg/dL in term or 7 mg/dL in preterm infants and is the most common calcium disorder in newborns, affecting up to 30% of those under 1,500 g. Early-onset disease within 72 hours is usually transient and driven by prematurity, while late-onset disease reflects hypoparathyroidism or maternal vitamin D deficiency.",
376: "Juvenile polyps are benign hamartomatous lesions and the most common intestinal polyps in children, making up over 90% of pediatric colonic polyps and occurring in 1-2% of children under 10, peaking at 2-6 years. They cause intermittent painless rectal bleeding, and colonoscopy rather than rectal examination is needed because up to half of children have a synchronous polyp elsewhere.",
378: "Language delay is development that follows the normal sequence but at a slower rate, and is the most common developmental concern parents raise, affecting boys three to four times more often than girls. About 60% catch up by age 4, but persistent delay at school entry carries risk of language-based learning disability, and intellectual disability accounts for half of cases.",
380: "The lateral [[128|ankle sprain]] is the most common acute ankle injury in young athletes, caused by inversion and plantarflexion, and its pattern depends on skeletal maturity, since only mature adolescents sustain adult-type ligament injury. Treatment is conservative with ice, elevation and bracing, and the Low-Risk Ankle Rule safely avoids radiography when tenderness is confined to the distal fibula.",
386: "Parasitic disease is a major cause of pediatric morbidity worldwide, but children who have only lived in developed countries are usually free of tissue parasites, and the infections acquired in the US are giardiasis, pinworm and head lice. Intestinal worms rarely cause diarrhea, protozoa do, and over 90% of stool ova-and-parasite tests are negative, so PCR is the better test.",
394: "Primary amenorrhea is failure to ever menstruate, defined as no menarche by 15 with normal secondary sexual characteristics, by 13 without them, or more than 3 years after thelarche. Unlike secondary amenorrhea it usually reflects a genetic or anatomic cause, led by Turner syndrome at about 43% and Müllerian agenesis at 15%, and pregnancy must still be excluded.",
395: "Short bowel syndrome is reduced functional intestinal mass below what is needed for normal growth, and is the leading cause of pediatric intestinal failure at 44-45% of cases, most often after resection for necrotizing enterocolitis. Preservation of the ileum and ileocecal valve is the strongest prognostic factor, and early enteral feeding drives bowel adaptation, with survival now above 90%.",
400: "Thrombocytopenia is a platelet count below 150,000/mm3, arising from reduced production, increased destruction or splenic sequestration, and immune thrombocytopenia is the most common cause in an otherwise well child aged 2-10 after a viral illness. It is a diagnosis of exclusion needing no extra tests when classic, and 60-75% resolve within 2-4 months whatever the treatment.",
401: "Tinea versicolor is a benign superficial infection caused by Malassezia, a yeast that is normal skin flora, and is more accurately called pityriasis versicolor because it is not a true dermatophyte. It produces scaly macules on the upper trunk that fail to tan, and treatment is selenium sulfide or topical antifungals, though recurrence is common.",
402: "Trichomoniasis is caused by the flagellated protozoan Trichomonas vaginalis and is the most common non-viral sexually transmitted infection in the US, though nearly all infected men and up to half of women have no symptoms. Perinatal infection is usually self-limited, but [[404|vulvovaginitis]] in a prepubertal child should prompt a sexual abuse investigation.",
403: "Urethritis is inflammation of the urethra presenting with dysuria plus urethral discharge or blood spotting on the underwear, and unlike in adults, infection is an uncommon cause in children, where trauma, chemical irritation and foreign bodies matter more. Every child under 2 and any boy with urinary symptoms should be evaluated for congenital anatomic abnormality such as vesicoureteral reflux.",
}