A Cervical Epidural Steroid Injection (CESI) manages severe neck and arm pain (cervical radiculopathy) caused by nerve irritation. This irritation usually stems from inflammation due to a herniated disc or spinal stenosis in the cervical spine. The injection delivers anti-inflammatory medication directly into the epidural space surrounding the spinal nerve roots to reduce swelling and pressure. Although CESI aims for relief, pain often feels worse immediately following the procedure, sometimes spiking higher than before the injection. This temporary increase in discomfort is common.
The Temporary Post-Injection Pain Flare
The most frequent reason for a short-term pain increase is a chemical reaction called a “steroid flare” or “cortisone flare.” This relates to the particulate nature of certain corticosteroid formulations. The injected solution contains microscopic crystals that irritate the already sensitized nerve tissue before dissolving. This irritation triggers a localized, temporary inflammatory response, causing a noticeable spike in neck and arm pain. The flare typically begins a few hours after the procedure, once the immediate numbing effect of the local anesthetic wears off, and generally peaks within the first 24 to 48 hours before resolving.
Procedural Irritation and Fluid Pressure Effects
Beyond the chemical steroid flare, the physical act of the injection introduces mechanical factors that cause temporary discomfort. The procedure requires navigating a needle through tissue layers near delicate nerve structures to reach the epidural space. Even with imaging guidance, needle placement can cause minor, localized irritation or trauma to the sensitive tissues and the nerve root. Another factor is the immediate effect of fluid volume within the confined epidural space. The injected mixture temporarily increases pressure, which can exert brief but painful pressure on an already compressed or inflamed nerve root until the fluid disperses.
Recognizing Serious Underlying Complications
While a temporary pain increase is common, a significant, sustained worsening of symptoms can rarely indicate a serious underlying complication. These events require immediate medical attention. One such complication is an epidural hematoma, a collection of blood that compresses the spinal cord or nerve roots, potentially leading to new neurological deficits. Another rare concern is infection, such as an epidural abscess or meningitis, which presents with systemic symptoms. Signs of infection include a high fever, severe headache, and pain that continues to worsen beyond the expected 48-hour window of a typical steroid flare. Direct nerve or spinal cord injury, while extremely rare, is accompanied by the immediate onset of new, severe neurological symptoms like weakness, numbness, or changes in bowel or bladder function.
When to Contact Your Doctor and Next Steps
Understanding the typical timeline is key to managing expectations after a CESI. Temporary pain relief from the local anesthetic lasts a few hours, and the steroid flare usually resolves within two days. The therapeutic benefit of the steroid, which is the primary anti-inflammatory effect, typically begins to be felt between three and seven days after the injection. During the initial period, managing the temporary discomfort with rest and applying ice to the injection site, as directed by the physician, is the standard approach. It is necessary to contact your physician immediately if you experience any of the “red flag” symptoms that suggest a serious complication.
Red Flag Symptoms
These symptoms warrant an immediate call for medical guidance:
- A fever of 100.5°F or higher.
- A new onset of severe headache.
- Pain that steadily increases rather than decreases after the 48-hour post-injection period.
- New neurological deficits, such as a sudden loss of strength or persistent numbness.
- A change in your ability to control your bladder or bowels.