Facial flushing after a cortisone injection happens because the steroid is absorbed into the bloodstream and temporarily widens blood vessels near the skin’s surface, particularly in the face. It is one of the most common systemic side effects of corticosteroid injections, reported in roughly one in four to one in three patients depending on the steroid used and the injection site. The reaction is almost always harmless and self-limiting, but it can be alarming when nobody warned you it might happen.
How Common It Is and How Long It Lasts
Flushing rates vary depending on the steroid formulation, the dose, and where the injection is placed, but it is far from rare. In a prospective study of 150 patients receiving epidural injections of dexamethasone (a commonly used corticosteroid), flushing occurred in about 28% of cases. All of the patients who experienced flushing saw it resolve within 48 hours.1PubMed Central. Flushing following interlaminar lumbar epidural steroid injection with dexamethasone That timeline is fairly typical across different injection types. Most people notice the warmth and redness begin within hours of the injection, sometimes within minutes. For many, the flushing is most intense on the first day and fades by the second.
About a quarter of patients who developed flushing in that study noticed it before they even left the clinic, meaning it started within 30 minutes or so of the procedure.1PubMed Central. Flushing following interlaminar lumbar epidural steroid injection with dexamethasone The rest developed it later that day or the following day. Either pattern is normal. Flushing that appears suddenly on day three or four after an injection, or that comes with a spreading rash or difficulty breathing, is a different situation and worth a call to your doctor.
Why the Face Flushes Specifically
When a corticosteroid is injected into a joint, a bursa, or the epidural space, it does not just stay put. Some of the drug is absorbed into the general circulation. Once in the bloodstream, corticosteroids influence how blood vessels behave. They alter the production and activity of prostaglandins, which are chemical messengers that help control how much blood vessels constrict or dilate. The net effect in many people is temporary vasodilation: small blood vessels near the skin’s surface relax and widen, letting more blood flow through them.
The face gets disproportionately affected because facial skin is thinner than skin elsewhere on the body, and the network of tiny blood vessels just below it is dense. When those vessels dilate, the increased blood flow becomes visible as redness and is felt as warmth. The same mechanism can cause flushing on the chest, neck, and upper arms, but the face is where most people notice it first and most intensely.
This is the same basic vascular mechanism behind other common types of flushing, whether from alcohol, hot flashes, or certain medications. The trigger differs, but the end result is the same: more blood reaching the skin’s surface than usual, making it red and warm to the touch.
Which Steroids Are More Likely to Cause Flushing
Not all corticosteroid preparations carry the same risk. Clinicians use several different steroid formulations for injections, and they differ in how quickly they are absorbed, how long they stay active, and how readily they enter the bloodstream. The two broad categories are particulate steroids (like triamcinolone and methylprednisolone, which form tiny crystals that dissolve slowly at the injection site) and non-particulate steroids (like dexamethasone, which dissolves completely and is absorbed more rapidly).
You might expect the faster-absorbing steroid to cause more flushing, and there is some evidence pointing that way. The 28% flushing rate seen with dexamethasone epidural injections was described by the researchers as higher than rates previously reported with other steroid preparations.1PubMed Central. Flushing following interlaminar lumbar epidural steroid injection with dexamethasone However, the picture is not entirely straightforward. A separate study comparing systemic effects of dexamethasone against triamcinolone found that dexamethasone produced fewer overall systemic side effects, even at a slightly higher equivalent dose.2PubMed Central. Systemic effects of fluoroscopically guided epidural steroid injection with dexamethasone The apparent contradiction likely reflects the fact that “systemic effects” is a broad category. Dexamethasone may cause more flushing specifically while producing fewer other side effects like blood sugar spikes or insomnia.
Triamcinolone, meanwhile, is notorious for causing flushing after joint injections. Many patients receiving a knee or shoulder injection with triamcinolone report facial flushing that night or the next day. The particulate nature of triamcinolone means the steroid releases slowly from the injection site, and the flushing episode may come on more gradually and last a bit longer than with a rapidly absorbed formulation.
If you have had flushing with one steroid and want to avoid it next time, it is worth asking your doctor whether a different preparation is an option. Switching formulations does not guarantee the flushing will not recur, but individual responses to different steroids vary enough that it is a reasonable conversation to have.
Who Is More Likely to Flush
Women appear to be significantly more prone to post-injection flushing than men. In the dexamethasone epidural study, about two-thirds of patients who experienced flushing were female, a difference that reached statistical significance.1PubMed Central. Flushing following interlaminar lumbar epidural steroid injection with dexamethasone This fits with broader patterns in medicine: women tend to flush more readily in response to a range of triggers, from hormonal shifts to medications. Estrogen and other sex hormones influence vascular reactivity, making blood vessels in women more responsive to vasodilating stimuli.
Beyond sex, lighter skin makes flushing more visible, which can create the impression that lighter-skinned individuals are more susceptible. In reality, the vasodilation occurs regardless of skin tone, but it is easier to see in people with less melanin. People with darker skin may experience the same warmth and sensation without the obvious redness.
Pre-existing conditions that affect blood vessels can also play a role. If you already deal with rosacea, for example, your facial blood vessels are more reactive at baseline, and a cortisone injection may temporarily worsen the redness. Similarly, people who flush easily with alcohol, spicy food, or emotional triggers seem anecdotally more likely to flush after steroid injections, though formal studies specifically quantifying that overlap are limited.
Telling Flushing Apart from an Allergic Reaction
This is the question that actually worries most people. You get a cortisone injection, your face turns red a few hours later, and you start wondering if you are having an allergic reaction. The two look superficially similar, but they behave quite differently.
Steroid-induced flushing is typically diffuse, meaning your whole face (and sometimes chest and neck) turns warm and red. It is not itchy, or at most mildly so. There is no swelling of the lips, tongue, or throat. There is no hive-like raised rash. It does not get progressively worse over hours. It feels like a sunburn or a hot flash, and it fades on its own, usually within a day or two.
An allergic reaction, by contrast, tends to involve hives (raised, itchy welts), localized swelling, and sometimes breathing difficulties. Anaphylaxis, the most severe form, comes on rapidly, usually within minutes, and involves a dramatic drop in blood pressure, throat tightening, and widespread hives. True allergic reactions to corticosteroids do exist but are quite rare. When they occur, they are usually triggered not by the steroid itself but by a preservative or other inactive ingredient in the injection formulation.
A good rule of thumb: if the redness is evenly spread across your face, is not itchy, and your breathing is normal, you are almost certainly dealing with a straightforward flushing reaction. If you develop raised welts, if your face or tongue starts swelling, or if you feel any tightness in your throat, seek medical attention immediately.
What You Can Do About the Flushing
Since the flushing is self-limiting and generally resolves within 48 hours, aggressive treatment is rarely needed. But when your face feels like it is on fire and you want to be comfortable, a few things help.
- Cool compresses: A damp cloth or a cold pack wrapped in a towel, applied to the face for 10 to 15 minutes at a time, narrows blood vessels temporarily and provides relief.
- Avoid triggers: Alcohol, hot beverages, spicy food, intense exercise, and very hot showers all promote vasodilation and can make flushing worse while the steroid is still circulating. Steering clear of these for a day or two after the injection helps.
- Over-the-counter antihistamines: Some clinicians suggest taking an antihistamine like diphenhydramine or cetirizine before or after the injection. The evidence that this meaningfully reduces steroid flushing is thin, since histamine is not the primary driver of the vasodilation, but some patients report it helps take the edge off.
- Stay cool: Keeping your environment cool and wearing light clothing reduces the total vasodilatory load on your skin.
Prescription-strength treatments are generally unnecessary for a reaction lasting a day or two. If your flushing is severe enough that you dread future injections, bring it up with your doctor before the next one. Adjusting the steroid type, the dose, or the injection technique may reduce the severity.
Other Systemic Effects That Can Tag Along
Flushing is not the only sign that the steroid has entered your bloodstream. Other common systemic effects after a cortisone injection include a temporary rise in blood sugar (particularly relevant if you have diabetes), difficulty sleeping for a night or two, a brief burst of energy or restlessness, and mild mood changes. These effects follow the same basic pattern as flushing: they result from the steroid circulating systemically rather than staying confined to the injection site, and they typically wear off within a few days.
For people with diabetes, the blood sugar spike is worth planning for. Blood glucose can rise significantly for two to five days after a steroid injection, and adjustments to insulin or oral medications may be necessary. If you have diabetes and are scheduled for a cortisone injection, let both your prescribing doctor and your endocrinologist or primary care provider know so you can plan ahead.
Another effect worth knowing about, though it applies more to repeated injections than to a single shot, is suppression of your body’s own cortisol production. Corticosteroids are synthetic versions of cortisol, the stress hormone your adrenal glands produce naturally. When you receive an injection, the exogenous steroid signals to the brain that cortisol levels are high, and the feedback loop temporarily dials down your own production.3Europe PMC. Recovery of steroid induced adrenal insufficiency After a single injection, this suppression is brief and clinically insignificant for most people. But patients who receive multiple steroid injections over weeks or months can develop more sustained suppression that takes time to recover from. Screening with a morning blood cortisol level is one practical way to monitor this in patients receiving repeated injections.4Oxford Academic. Serum cortisol level to screen for significant hypothalamic-pituitary-adrenal axis suppression in patients receiving multiple steroid injections
Why Doctors Often Forget to Mention It
One of the most frustrating aspects of post-injection flushing is that patients frequently are not warned about it beforehand. In clinical practice, the consent conversation before a cortisone injection tends to focus on the more serious (though much rarer) risks: infection at the injection site, tendon weakening, and local tissue atrophy. Flushing, because it is benign and self-resolving, often gets left out of the discussion.
The result is that patients are blindsided. They go home, their face turns red and hot, and they spend the evening searching online to figure out if something went wrong. A brief heads-up from the clinician would save a lot of anxiety. If you have an injection coming up and flushing has not been mentioned, ask about it. Knowing what to expect makes the experience far less alarming.
When Flushing After an Injection Deserves a Closer Look
In the vast majority of cases, flushing is a nuisance and nothing more. But a few scenarios warrant follow-up rather than a wait-and-see approach.
Flushing that lasts beyond three days, or that gets noticeably worse rather than better over time, is unusual for a steroid reaction and should prompt a call to your provider. Flushing accompanied by a fever above 100.4°F (38°C) raises the question of whether an infection is developing at the injection site, a rare but serious complication of any injection. And flushing that starts several days after the injection, rather than within the first 24 hours, does not fit the typical pharmacological timeline and may point to something else entirely.
People who receive cortisone injections frequently, such as those managing chronic joint conditions, sometimes notice that flushing becomes more predictable with experience. You may find that it happens every time, or that it only happens with certain steroid types. Keeping a mental note of which formulations cause the reaction gives you useful information for future conversations with your doctor about what to use and what to avoid.
For patients with conditions that already involve flushing, like carcinoid syndrome or mastocytosis, a cortisone injection can briefly worsen their baseline symptoms. These patients should make sure their care team is aware of the underlying condition before receiving any steroid injection, since additional vasodilatory stress on an already reactive vascular system can make for an uncomfortable few days.