Main Document
The otolaryngologist’s non-surgical toolbox for treating sinonasal
allergies is practically empty. Allergy patients have nearly universally
failed topical steroids and frontline oral medications prior to being
evaluated by a specialist. For those who don’t meet criteria for
surgery, the options are underwhelming; Switch to another topical
formulation? Pass it off to an allergist? In the 1950’s and ‘60’s, such
patients routinely underwent a different treatment-an intranasal steroid
injection (Figure I ). This simple, inexpensive, and
historically extremely effective intervention was once standard of care
in otolaryngology clinics across the world. Typically performed every
few months, systemic complications, such as elevated serum glucose, were
transient and clinically-insignificant. That was before a series of now
infamous case reports appeared describing blindness following intranasal
injections. The intervention rapidly fell out of favor, and has remained
sidelined ever since.
Multiple prior reviews have analyzed these safety concerns, ultimately
making an argument in support of intranasal steroid
injections.1,2 A review from 2015 described
significant deviations from the correct technique in the published
reports of visual complications; many were done on asleep patients, with
deep injections rather than submucosal, and some with large gauge
needles.1 Collectively, from case series published by
otolaryngologists who routinely performed injections, a mere three
visual complications were reported out of 117,669 injections (0.003%).
All of these disturbances resolved spontaneously, yielding a pristine
0% rate of permanent complications from experienced providers. Still
however, interest in reviving the procedure remains nearly non-existent.
It’s intriguing that nasal injections of cosmetic fillers are still
commonly done despite similar experiences with visual complications. In
fact, of all the routine cosmetic filler injection sites, nasal
injections have been reported to carry the highest risk of
blindness.3 Does it make sense that some providers
will routinely accept a risk of blindness for a cosmetic procedure,
while others won’t even consider an analogous treatment for quality of
life-impacting allergies?
A cursory review of steroid pharmacology provides additional insights.
An overwhelming majority of the intranasal injections performed in the
mid-20th century were done using triamcinolone, methylprednisolone or
other “particulate” steroid formulations. The term “particulate”
refers to the tendency of the steroid molecules to bind together,
forming microscopic yet mass-occupying collections that can impart a
prolonged treatment effect. When one of these clumps of steroid enters
choroidal or retinal vessels via collateral vasculature in the
intranasal space, a vision-threatening thromboembolism can result. Such
is the widely agreed-upon theory of how intranasal injections caused
episodes of blindness.1,2
What about dexamethasone? This newer-age steroid is ubiquitous and
widely used on an international level by providers of nearly all
specialties. Importantly, dexamethasone is a non -particulate
formulation; that is, it does not have the propensity to form
mass-occupying microscopic collections. As such, one could argue a
theoretical non-existent risk of visual deficits from an intranasal
dexamethasone injection. The medication simply doesn’t have the
pharmacologic property that underlies the mechanism of the complication.
As time goes by, the intranasal cavity stands taller and taller on an
increasingly shorter list of anatomic sites into which dexamethasone is
NOT routinely injected.
A look over the shoulder of our subspecialist colleagues adds more to
the story. Orthopedists and neurosurgeons had more than their fair share
of particulate steroid-related complications: There are numerous case
reports and series describing permanent paralyses following spinal
injections. In contrast to what happened in otolaryngology, these
providers continued to implement the highly effective treatment,
oftentimes making a switch to non-particulate formulations. To date,
there have been no reports of paralyses with non-particulate injections.
Furthermore, a recent meta-analysis found no difference between symptom
control for particulate vs. non-particulate spinal injections, thus
suggesting that the safety benefit of non-particulates can be achieved
without sacrificing effectiveness.4 Opthalmologists
will not uncommonly administer steroids directly to the intra-vitreal
space; and there have yet to be issues with significant adverse events.
There’s even an FDA improved dexamethasone-eluting implant that’s placed
within the globe. Multiple prior studies have shown no issues with
pathologically increased intra-ocular pressures or any other type of
significant visual complication.5,6 If dexamethasone
can be safely implanted within the actual globe, how worried do we need
to be about ophthalmologic complications of a submucosal intranasal
injection?
Steroids aside, there’s really minimal interest among otolaryngologists
to inject any medication intranasally aside from pre-operative
lidocaine and epinephrine. Botox, for example, has been shown to be both
safe and effective for refractory rhinitis in multiple small
series.7 This treatment could be viewed as a chemical
vidian neurectomy, without the risk of permanent anhydrosis that has
kept the surgery from mainstream practice. Despite the promise that’s
been shown, intranasal botox remains nowhere near as popular as it is
for the treatment of salivary glands or cervicofacial dystonias for
example. Many anti-histamines are available in intravenous form, has
anyone thought of giving those a try? What about a neuromodulator like
gabapentin? Sure, injections of these medications may not be the answer
for our refractory allergy patients. But the fact that these simple
measures have never even been tried over the years despite an
established burden of disease is highly suggestive of a purposeful
aversion. This avoidance truly may not be evidence-based. We’re amidst
an explosion of office rhinology procedures driven by costly,
sophisticated devices such as sinus and eustachian tube balloons, stents
of various kinds, and other nasal implants, many of which have a
debatable effectiveness. These are industry-promoted, revenue-driven
products. It would be a shame if a simple and historically effective
procedure-a simple intranasal injection, remained sidelined from the
otolaryngology practice as a result of misperceptions.