A subperiosteal abscess is a localized collection of pus that forms between a bone and its periosteum, which is the thin membrane covering the surface of most bones. This membrane contains blood vessels and nerves that provide nourishment and support for bone growth and repair. When an infection takes hold in this space, it can accumulate purulent material, leading to pressure and localized inflammation.
Causes and Common Locations
Subperiosteal abscesses typically arise when an infection spreads from a nearby source to the area between the bone and its periosteum. The bacteria, often Staphylococcus aureus or Streptococcus species, can travel through various pathways, including direct extension, through small bone defects, or via the bloodstream.
One common location is the orbit, where an abscess often develops as a complication of a sinus infection. The thin bone separating the sinuses from the eye socket, the lamina papyracea, can allow infection to spread, particularly from the ethmoid or maxillary sinuses. These orbital abscesses are seen frequently in children due to their developing bone structure. Dental infections can also lead to subperiosteal abscesses in the jaw or surrounding facial bones.
Infections of the middle ear can extend to the mastoid bone located behind the ear, resulting in a mastoid subperiosteal abscess. This occurs when the infection breaches the mastoid air cells and collects under the periosteum. Lastly, subperiosteal abscesses on long bones can stem from bone infections (osteomyelitis) or direct trauma that introduces bacteria into the area.
Identifying Symptoms
General indicators include intense, localized pain over the affected bone, swelling, and redness of the overlying skin. Fever and a general feeling of being unwell are also common signs of infection within the body.
Symptoms vary depending on the abscess’s location. An orbital subperiosteal abscess may cause the eyeball to protrude (proptosis), pain when moving the eye, and double vision due to pressure on the eye muscles. Swelling and redness of the eyelid are also common, and vision may be impaired. For a dental subperiosteal abscess, severe toothache, swelling of the face, and difficulty opening the mouth can be present. A mastoid subperiosteal abscess causes pain and swelling behind the ear, along with possible ear discharge and a reduction in hearing.
The Diagnostic Process
Diagnosis begins with a thorough physical examination. The doctor will assess the affected area for signs of swelling, tenderness, warmth, and redness, noting the extent of the inflammation. They will also inquire about the onset and progression of symptoms and any recent infections or injuries.
Imaging tests are then used to confirm the presence and exact location of the abscess. A computed tomography (CT) scan is often used, as it provides detailed cross-sectional images that can visualize the collection of pus, determine its size, and help identify the underlying source of infection, such as a sinus or tooth. Magnetic resonance imaging (MRI) may also be used, offering high-resolution images that help differentiate the abscess from other inflammatory conditions and show the extent of bone marrow involvement. Blood tests are also performed to check for indicators of infection, such as an elevated white blood cell count.
Medical and Surgical Treatments
Treatment for a subperiosteal abscess involves surgical intervention and antibiotic therapy to effectively resolve the infection. Surgical drainage is necessary to remove the accumulated pus, which alleviates pressure on the surrounding tissues and helps to clear the infection. This procedure may involve making an incision to access the abscess cavity, allowing the pus to be drained.
Following surgical drainage, intravenous (IV) antibiotics are administered to eliminate the bacteria causing the infection. Common bacteria include Staphylococcus aureus and Streptococcus species; initial antibiotic choices may include broad-spectrum agents like clindamycin or a combination of ceftriaxone and metronidazole. Patients receive IV antibiotics, often 24 to 48 hours post-surgery, until clinical improvement. This is followed by oral antibiotics, such as amoxicillin-clavulanate or clindamycin, for several weeks to ensure complete eradication and prevent recurrence.
Recovery and Potential Complications
Recovery from a subperiosteal abscess involves hospitalization, often for several days, for intravenous antibiotic administration and monitoring after surgical drainage. During this time, medical staff will assess the patient’s response to treatment, looking for reductions in pain, swelling, and fever. Follow-up appointments are scheduled to ensure the infection has cleared and to monitor for lingering effects or new concerns.
If left untreated, a subperiosteal abscess can lead to severe complications from infection spreading. An orbital abscess can result in permanent vision loss due to pressure on the optic nerve. A mastoid abscess can cause hearing loss or spread further into the skull. Any subperiosteal abscess can also lead to widespread infection in the bloodstream, a life-threatening condition known as sepsis, or extend to the brain, causing serious conditions like meningitis or brain abscesses.