The term cephalhematoma refers to an accumulation of blood between the periosteum of the skull and calvarium, due to a hemorrhage from periosteal vessels. This condition is typically caused by perinatal head traumas.
Cephalhematoma is a very common perinatal injury and thus most frequently diagnosed in neonates. Premature infants and those presenting excess birth weight are more often affected. Detailed information regarding the delivery commonly reveal cephalopelvic disproportion, dystocia or prolonged labor, or use of instruments like forceps or vacuum extraction devices.
If such a hematoma persists for unusually long periods of time, starts to increase in size or if signs of inflammation become visible around it, it might have become infected. In these cases, children may also present fever and feeding difficulties, but these are not exclusion criteria.
Cephalhematomas are diagnosed upon visual inspection and palpation. They manifest as immobile, firm swellings above the neonate's skull. The scalp, in contrast, is not attached to this swelling and moves freely. Parietal and occipital bones are most commonly affected, but hematomas have also been observed in frontal regions.
Unfortunately, there is no non-invasive method that allows to determine with absolute certainty if a cephalhematoma is infected. Nevertheless and due to the threat posed by a possibly infected hematomas, laboratory analyses should be realized upon minimal suspicion of infection. Analyses of blood samples should be carried out and may reveal elevated levels of inflammatory markers. Diagnostic imaging techniques are little sensitive for early tissue alterations. While enhanced magnetic resonance imaging may display early signs of periosteal inflammation, computed tomography only confirms infection if osteomyelitis already developed . The method of choice to prove infection is diagnostic aspiration and this procedure should be realized if increased concentrations of inflammatory markers have been found and magnetic resonance imaging revealed periosteal inflammation  . Aspiration should be carried out strictly aseptically. It is also a method of treatment.
If an infection cannot be detected but unusual symptoms persist, these may stem from a linear skull fracture. Thus, workup by means of imaging techniques is indicated.
Most frequently, cephalhematomas do not require any treatment.
Diagnostic and therapeutic aspiration should not a priori be realized because of the risk of secondary infection. Such an infection might possibly cause osteomyelitis, meningitis or abscess formation. On the other hand, if an infection is detected by diagnostic aspiration, drainage of the cephalhematoma may considerably relieve the bacterial load of the patient. Infected hematomas indicate antibiotic therapy over the course of two to six weeks . If the infection is restricted to the cephalhematoma, short therapy duration may be sufficient; osteomyelitis justifies administration of antimicrobial for longer periods of time.
Hemolysis of blood sequestered in the hematoma may lead to anemia, hyperkalemia and jaundice. In severe cases and if first signs of jaundice become visible, bilirubin and potassium levels should be monitored. However, they rarely reach alarming values.
Over the course of recovery, cephalhematoma may calcify or even ossify. These processes do not require any immediate therapy and only if so wished, aesthetic surgery may be carried out later in life to remove bulging deformities. Of note, the overall time for recovery might be prolonged to several months in cases of calcification and ossification.
Linear skull fractures do not usually need to be treated, depressed skull fractures, however, should be attended .
Cephalhematoma is generally a benign, self-limiting condition. In most cases, complete spontaneous remission can be expected within one month .
Cephalhematomas almost exclusively stem from traumatic impacts sustained during birth. Such traumas may be caused by an abnormally large head of the neonate, macrosomia, cephalopelvic disproportion or inappropriate, rough handling of the baby during normal delivery or cesarean section. However, these hematomas have also been described in newborns that did not undergo any such manipulation. Pressure differences between the intra- and extrauterine space may account for these cases, but this hypothesis could not yet be proven. Other potential risk factors are increased susceptibility due to prematurity, obstructed and/or prolonged labor as well as, somewhat surprisingly, breech birth .
Cephalhematoma is a frequently observed birth injury. In Nigeria, this kind of lesion has been reported to account for almost 50% of all types of birth injury . Its overall incidence has been estimated to range between 1 and 3% of live births. If certain forms of delivery are considered, the share of affected neonates may be even higher. In this line, instrumental deliveries, i.e., those carried out with the help of forceps or vacuum extraction, are associated with up to 4% of cephalhematoma  . In rare cases, they may already form before delivery starts. Here, incidence rates are presumably below 0.1%. No reliable data is available regarding cephalhematoma incidence due to inappropriate obstetric practice.
About one out of six patients suffers from bilateral lesions .
While the outer, fibrous layer of the periosteum contains mainly fibers and some fibroblasts, the inner, osteogenic layer of the periosteum consists of blood vessels, nerves and osteoblasts.
Blood vessels crossing through the inner periosteal layer may rupture upon trauma and such an event would give rise to a subperiosteal hemorrhage and subsequent formation of a hematoma. Trauma may easily be inflicted during birth, particularly if instruments such as forceps or vacuum extraction devices are used. The fact that incidence rates seem to be higher among premature infants argues for an individual predisposition depending on developmental stage. Trauma and surgery may also cause cephalhematomas at later points in life, although this is more rarely seen.
The pathogenetic mechanism behind cephalhematoma formation without blunt trauma is not yet completely understood. It has been speculated that minimal movements of the skull as triggered by prolonged compression create shear forces between the periosteal layers and the bone. These may contribute to blood vessel rupture. Such skull movements may be facilitated by the presence of only thin skull tables in infants.
While the majority of cephalhematomas is self-limiting and coagulated blood is resorbed without any complications, some may calcify and even ossify progressively. If need arises, extensive calcifications can be corrected for aesthetic reasons at later points in time. Anemia and hyperbilirubinemia have also been related to this entity. These are not unusual findings that result from hemolysis of blood sequestrated in the hematoma and generally subside without reaching threatening proportion. As indicated above, other, more serious complications comprise infection, subsequent osteomyelitis, meningitis and even sepsis. A Taiwanese study reported Escherichia coli and Staphylococcus aureus to be the most common causative agents of infected cephalhematomas  .
Linear skull fractures, rarely also depressed skull fractures may occur and are more common in those patients presenting bilateral hematoma. Presumably, they result from the same trauma that caused cephalhematoma or from non-related birth injuries rather than from the latter condition itself.
Good obstetric practices are the best way to prevent cephalhematomas. Macrosomia, cephalopelvic disproportion and possibly breech birth should be recognized early and the possibility of a cesarean section should be considered in the interest of mother's and child's well being. Inappropriate, rough handling should be completely avoided. It has been estimated that about half of all cases could be avoided by adopting these measures.
Similar to bones anywhere in the human body, the skull is covered by a thin but resistant periosteal layer. That, in turn, is tightly attached to the underlying skull, notably at points of fibrous joints between cranial bones, and lies beneath the epicranial aponeurosis that connects to several frontal and occipital muscles. The epicranial aponeurosis is a dense fibrous tissue that leaves little room for stretching. Above this aponeurosis there is the scalp.
The cranial periosteum contains various blood vessels which may rupture if traumas are sustained. Such events may give rise to the formation of a hemorrhage inside the tight space between skull and periosteum, possibly elevating the epicranial aponeurosis and designated a cephalhematoma  . That means this term refers to a subperiosteal extracranial hematoma. A hemorrhage between the cranial periosteum and the epicranial aponeurosis is denominated subgaleal hematoma. This is indeed a potential differential diagnosis that should be ruled out because it may be associated with more severe consequences, e.g., hypovolemia and coagulopathy .
Cephalhematomas are benign hemorrhages most frequently observed in newborns, notably in neonates with an absolutely or relatively large head that were subjected to normal delivery. Of note, this kind of hematoma may also form after cesarean sections. In both cases, cephalhematomas result from a trauma sustained during birth  . This pathology has also been described in neonates that did not sustain any trauma during normal delivery or cesarean section and it has been speculated that the pressure difference between the intrauterine and extrauterine space may account for it here. Cephalhematomas are rarely seen in older patients and if they are detected here, they most likely also result from trauma or surgical intervention.
They most commonly affect the periosteum covering parietal and occipital bones. Cephalhematomas are usually self-limiting, the accumulated blood is gradually resorbed without any specific treatment becoming necessary. In some cases, calcification and progressive ossification can be observed over the course of the following weeks and months. No health problems should arise from this process.
Moreover, they should be monitored closely since serious complications have been described in isolated cases. For instance, they might become infected and infection could spread to the underlying osseous structures and meninges  . Such an infection might be confirmed or ruled out by diagnostic aspiration, but this diagnostic measure also bears the risk of secondary infection . Imaging techniques will not be helpful to diagnose cephalhematoma infection until changes become visible in the underlying bone.
The cranial bones are covered by a thin tissue called periosteum. The periosteum itself consists of two layers: an inner layer full of blood vessels, nerves and cells required for bone formation; and an outer layer that contains only few cells but a lot of resistant, coarse fibers. With regards to the skull, the periosteum is covered by a tendon-like, extensive structure, an aponeurosis, and the skin.
If blood vessels of the inner periosteal layer rupture, a hemorrhage occurs and a cephalhematoma develops. However, the underlying bone and the overlying dense layer of the outer periosteum limit the space that can fill up with blood and the hemorrhage does not pose a major threat to the patient's health.
Cephalhematomas are most frequently diagnosed in newborn children. Here, periosteal blood vessels may have ruptured during birth, particularly if the child was born with excess weight, if the mother is of a rather small stature, or if the delivery took a very long time. Additional risk factors for this type of hematoma are premature birth, breech birth and the use of instruments such as forceps or vacuum extraction devices to accelerate the delivery.
In some children, cephalhematoma cannot be related with birth injuries. In these cases, the cause is unknown.
In those rare cases where Cephalhematomas are detected in older patients, they are also associated with trauma or surgery.
Some hours after birth, a swollen area can be detected on the head of the child. It is immobile and firm, and the scalp can easily be moved above it.
Cephalhematoma usually undergo spontaneous remission. Over the course of recovery, children may nevertheless develop jaundice. The yellow touch of the child's skin would then stem from lysis of red blood cells sequestered within the hematoma. Jaundice most commonly disappears without any complication. Also, the hematoma may start to harden, to calcify and ossify. If this is the case, a surgical excision may be realized at later points in time to correct the unaesthetic bulge of the skull.
Diagnosis is based on clinical examination.
In rare cases, cephalhematomas may become infected and because bacteria may spread and cause osteomyelitis and meningitis, bacterial infection should be recognized as early as possible. Thus, if the child starts to present feeding difficulties, develops fever, if the skin surrounding the hematoma becomes red and warm, additional diagnostic measures will be undertaken to confirm or rule out infection. Eventually, the cephalhematoma may be drained to obtain fluid samples that can be analyzed for the presence of bacteria.
In most cases, cephalhematoma do not require any treatment. They are self-limiting and the blood is resorbed within approximately one month. Recovery may take longer in cases of calcification and ossification.
An infected hematoma is treated with antibiotics.