Editing Jaundice (section)

=== Neonatal jaundice ===
{{main|Neonatal jaundice}}
==== Symptoms ====
Jaundice in infants presents with yellowed skin and icteral sclerae. Neonatal jaundice spreads in a cephalocaudal pattern, affecting the face and neck before spreading down to the trunk and lower extremities in more severe cases.<ref>{{cite book | vauthors = Telega GW |chapter=Jaundice|date=2018|title=Nelson Pediatric Symptom-Based Diagnosis|pages=255–274.e1|publisher=Elsevier|doi=10.1016/b978-0-323-39956-2.00015-7|isbn=978-0-323-39956-2}}</ref> Other symptoms may include drowsiness, poor feeding, and in severe cases, unconjugated bilirubin can cross the blood-brain barrier and cause permanent neurological damage ([[kernicterus]]).

==== Causes ====
The most common cause of jaundice in infants is [[Physiologic jaundice|normal physiologic jaundice]]. Pathologic causes of neonatal jaundice include:
* Formula jaundice<ref>{{cite journal|vauthors=Bertini G, Dani C, Tronchin M, Rubaltelli FF|date=March 2001|title=Is breastfeeding really favoring early neonatal jaundice?|journal=Pediatrics|volume=107|issue=3|pages=E41|doi=10.1542/peds.107.3.e41|pmid=11230622|doi-access=free}}</ref>
* [[Hereditary spherocytosis]]
* [[Glucose-6-phosphate dehydrogenase deficiency]]
* [[Pyruvate kinase deficiency]]
* [[ABO blood group system|ABO]]/[[Rh blood group system|Rh]] blood type autoantibodies
* [[Alpha 1-antitrypsin deficiency]]
* [[Alagille syndrome]] (genetic defect resulting in hypoplastic intrahepatic bile ducts)
* [[Progressive familial intrahepatic cholestasis]]
* [[Pyknocytosis]] (due to vitamin deficiency)
* [[Cretinism]] (congenital hypothyroidism)
* Sepsis or other infectious causes

==== Pathophysiology ====
Transient [[neonatal jaundice]] is one of the most common conditions occurring in newborns (children under 28 days of age) with more than 80 per cent experienceing jaundice during their first week of life.<ref>{{cite journal | vauthors = Maisels MJ | title = Managing the jaundiced newborn: a persistent challenge | journal = CMAJ | volume = 187 | issue = 5 | pages = 335–343 | date = March 2015 | pmid = 25384650 | pmc = 4361106 | doi = 10.1503/cmaj.122117 }}</ref> Jaundice in infants, as in adults, is characterized by increased bilirubin levels (infants: total serum bilirubin greater than 5&nbsp;mg/dL).{{cn|date=March 2025}}

Normal physiological neonatal jaundice is due to immaturity of liver enzymes involved in bilirubin metabolism, immature gut microbiota, and increased breakdown of fetal hemoglobin (HbF).<ref>{{cite book|title=Oxford Handbook of Clinical Specialties|vauthors=Collier J, Longore M, Turmezei T, Mafi AR|publisher=Oxford University Press|year=2010|isbn=978-0-19-922888-1|chapter=Neonatal jaundice}}{{page needed|date=July 2015}}</ref> Breast milk jaundice is caused by an increased concentration of [[β-glucuronidase]] in breast milk, which increases bilirubin deconjugation and reabsorption of bilirubin, leading to persistence of physiologic jaundice with unconjugated hyperbilirubinemia. Onset of breast milk jaundice is within 2 weeks after birth and lasts for 4–13 weeks.{{cn|date=May 2022}}

While most cases of newborn jaundice are not harmful, when bilirubin levels are very high, brain damage—[[kernicterus]]—may occur<ref>{{cite web|date=February 23, 2015|title=Facts about Jaundice and Kernicterus|url=https://www.cdc.gov/ncbddd/jaundice/facts.html|url-status=live|archive-url=https://web.archive.org/web/20160808204002/http://www.cdc.gov/ncbddd/jaundice/facts.html|archive-date=8 August 2016|access-date=13 August 2016|website=CDC}}</ref><ref name="Kap2017" /> leading to significant disability.<ref name="family">{{cite journal|vauthors=Click R, Dahl-Smith J, Fowler L, DuBose J, Deneau-Saxton M, Herbert J|year=2013|title=An osteopathic approach to reduction of readmissions for neonatal jaundice|journal=Osteopathic Family Physician|volume=5|issue=1|pages=17–23|doi=10.1016/j.osfp.2012.09.005}}</ref> Kernicterus is associated with increased unconjugated bilirubin (bilirubin which is not carried by [[albumin]]). Newborns are especially vulnerable to this damage, due to increased permeability of the [[blood–brain barrier]] occurring with increased unconjugated bilirubin, simultaneous to the breakdown of fetal hemoglobin and the immaturity of gut flora. This condition has been rising in recent years, as babies spend less time in sunlight.{{Citation needed|date=June 2020}}

==== Treatment ====
Jaundice in newborns is usually transient and dissipates without medical intervention. In cases when serum bilirubin levels are greater than 4–21&nbsp;mg/dl (68–360&nbsp;μmol/L), infant may be treated with [[phototherapy]] or [[exchanged transfusion]] depending on the infant's age and prematurity status.<ref name="CMAJ2015" /> A [[bili light]] is often the tool used for early treatment, which consists of exposing the baby to intensive [[phototherapy]], which may be intermittent or continuous.<ref>{{cite journal | vauthors = Gottimukkala SB, Lobo L, Gautham KS, Bolisetty S, Fiander M, Schindler T | title = Intermittent phototherapy versus continuous phototherapy for neonatal jaundice | journal = The Cochrane Database of Systematic Reviews | volume = 2023 | issue = 3 | pages = CD008168 | date = March 2023 | pmid = 36867730 | pmc = 9979775 | doi = 10.1002/14651858.CD008168.pub2 | collaboration = Cochrane Neonatal Group }}</ref><ref>{{cite web |title=Bili Lights for Jaundice: Effectiveness for Neonatal and Adults {{!}} Heliotherapy Research Institute |url=https://heliotherapy.institute/bili-lights/ |access-date=2022-07-24 |language=en-US}}</ref> A 2014 systematic review found no evidence indicating whether outcomes were different for hospital-based versus home-based treatment.<ref>{{cite journal | vauthors = Malwade US, Jardine LA | title = Home- versus hospital-based phototherapy for the treatment of non-haemolytic jaundice in infants at more than 37 weeks' gestation | journal = The Cochrane Database of Systematic Reviews | issue = 6 | pages = CD010212 | date = June 2014 | volume = 2014 | pmid = 24913724 | doi = 10.1002/14651858.cd010212.pub2 | pmc = 10750451 }}</ref> A 2021 Cochrane systematic review found that sunlight can be used to supplement phototherapy, as long as care is taken to prevent overheating and skin damage.<ref name="Horn_2021">{{cite journal | vauthors = Horn D, Ehret D, Gautham KS, Soll R | title = Sunlight for the prevention and treatment of hyperbilirubinemia in term and late preterm neonates | journal = The Cochrane Database of Systematic Reviews | volume = 2021 | issue = 7 | pages = CD013277 | date = July 2021 | pmid = 34228352 | pmc = 8259558 | doi = 10.1002/14651858.CD013277.pub2 | collaboration = Cochrane Neonatal Group }}</ref> There was not sufficient evidence to conclude that sunlight by itself is an effective treatment.<ref name="Horn_2021" />  Bilirubin count is also lowered through excretion—bowel movements and urination—so frequent and effective feedings are vital measures to decrease jaundice in infants.<ref>{{cite journal| vauthors = O'Keefe L |date=May 2001|title=Increased vigilance needed to prevent kernicterus in newborns|url=http://aapnews.aappublications.org/cgi/content/full/18/5/231|url-status=live|journal=American Academy of Pediatrics|volume=18|issue=5|pages=231|archive-url=https://web.archive.org/web/20070927203356/http://aapnews.aappublications.org/cgi/content/full/18/5/231|archive-date=2007-09-27}}</ref>