II. Definitions
- Fontanelle size measurement
- Obtain anteroposterior diameter (AP)
- Obtain transverse diameter (T)
- Size = (AP + T) / 2
- Anterior Fontanelle
- Posterior Fontanelle
III. Exam: Anterior Fontanelle
- Palpate Fontanelle with infant sitting upright quietly
- Fontanelle should feel soft
- Fontanelle should not be sunken or bulging
- Other examination features
- Auscultate for bruit (suggests AV Malformation)
- Macewen's Sign (percussion of Fontanelle)
- Dull cracked-pot sound suggests increased ICP
IV. Causes: Abnormal Anterior Fontanelle
- Bulging Fontanelle causes
- Crying, coughing or Vomiting
- Increased Intracranial Pressure
- Hydrocephalus
- Meningitis or Encephalitis
- Hypoxic-ischemic injury
- Trauma
- Intracranial Hemorrhage
- Dermoid tumors of the scalp
- Sunken Fontanelle causes
- Decreased Intracranial Pressure (Dehydration)
- Large Fontanelle or delayed closure
- Small Fontanelle or early closure
- Early closure may be normal
- Always evaluate for Microcephaly
- Craniosynostosis
V. References
- Bates (1991) Physical Exam, Lippincott, p. 586
- Fuloria (2002) Am Fam Physician 65(1):61-8 [PubMed]
- Kiesler (2003) Am Fam Physician 67(12):2547-52 [PubMed]
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Related Studies
| Definition (NCI) | The four gaps in the skull of a neonate or fetus where the sutures converge. The bulging or depression of the membranous soft spots can be indicative of intracranial fluid buildup or systemic dehydration. |
| Concepts | Body Space or Junction (T030) |
| SnomedCT | 79361005 |
| English | Fontanelles, Set of fontanelles, Fontanelle, Fontanelles set, Fonticulus cranii, fontanelles, fontanelle, Fontanel of skull, Structure of fontanel of skull (body structure), Structure of fontanel of skull, Fontanel of skull, NOS |
| Spanish | estructura de la fontanela del cráneo (estructura corporal), estructura de la fontanela del cráneo, fontanela del cráneo |
Ontology: Structure of anterior fontanel of skull (C0224549)
| Concepts | Body Space or Junction (T030) |
| MSH | D055762 |
| SnomedCT | 77564006 |
| English | AF - anterior fontanelle, Anterior fontanelle, Fonticulus anterior, Fontanelles, Anterior, Fontanel, Anterior, Fontanelle, Anterior, Anterior Fontanelle, Anterior Fontanels, Anterior Fontanelles, Anterior Fontanel, Fontanels, Anterior, anterior fontanelle, Anterior fontanel of skull, Structure of anterior fontanel of skull (body structure), Structure of anterior fontanel of skull |
| French | Fontanelle antérieure |
| German | Vordere Fontanelle |
| Czech | fonticulus anterior, fonticulus major, čtyřcípý velký lupínek |
| Norwegian | Fremre fontanelle, Pannefontanelle, Fonticulus anterior, Store fontanelle |
| Spanish | estructura de la fontanela anterior del cráneo (estructura corporal), estructura de la fontanela anterior del cráneo, fontanela anterior del cráneo |
