Allergy or Sinusitis? A 5-Question Differentiation Guide
Prof. Dr. Gediz Murat Serin – Ear Nose Throat Specialist | Teşvikiye ENT Group
Introduction: Why Is This Distinction Important?
A significant portion of patients who visit my clinic come assuming they are “sinusitis patients” due to long-standing nasal congestion, discharge, headaches, and loss of smell; while others, despite having an allergic background for years, downplay this condition, thinking “it will pass.” However, allergic rhinitis and sinusitis have different origins; treatment plans differ accordingly. Allergy is an excessive response of the immune system to environmental substances; sinusitis, on the other hand, is bacterial inflammation that often develops following a viral upper respiratory tract infection. In both cases, the mucosa lining the sinuses is affected.
In my nearly twenty years of ENT practice, as a physician working particularly in the field of endoscopic sinus surgery and other nasal function surgeries, I can clearly state this: Allergy and sinusitis often overlap in most patients; ignoring one while trying to treat the other creates grounds for relapses and unnecessary medication/antibiotic use. In this article, I will focus on distinguishing the two conditions under six main headings, also considering the real case dynamics in the field; I will add brief notes from my individual clinical approach throughout.
1) Duration and Seasonality
Allergic rhinitis shows a seasonal character in most patients. During spring and summer months, complaints become prominent following contact with pollen, house dust mites, mold spores, or pet hair. In some patients, allergies persist year-round; especially in cases where indoor allergens are dominant, seasonality becomes less distinct. Nevertheless, fluctuating nasal congestion throughout the day and consecutive sneezing attacks are typical.
Sinusitis, on the other hand, often begins following an upper respiratory tract infection. Nasal congestion lasting more than 10 days after recovering from a cold, thick colored postnasal discharge, a feeling of heaviness in the face and forehead area, and fullness that increases when bending forward are the most common findings we observe. Acute sinusitis responds to medical treatment during this period; complaints exceeding 12 weeks despite treatment suggest the need for imaging and advanced treatment.
Clinical note: In my routine practice, clarifying the history on a timeline significantly reduces unnecessary imaging and antibiotic use. Questions like “When did it start, how did the symptom curve progress, are there seasonal and environmental triggers?” form the backbone of differentiation.
2) Type and Color of Discharge
In allergy, the discharge is watery, colorless, and abundant. It may increase in the morning hours; this is the result of secretions accumulated overnight and the increased sneezing reflex upon waking. Nasal itching and a scratching sensation in the palate often accompany it.
In sinusitis, the discharge is thick, yellow-green in color, and sometimes foul-smelling. Postnasal drip creates a sticky sensation in the throat in the mornings; patients describe it as “it feels like it’s draining down my throat, I constantly want to clear it.” Unilateral thick discharge, accompanying toothache, or tenderness in the upper jaw increases the likelihood of odontogenic (dental origin) sinusitis.
Clinical note: The color and consistency of discharge alone does not make a diagnosis; however, when combined with the correct history, it is guiding. A yellow-green color change added to clear discharge in an allergic background often indicates secondary sinusitis.
3) Congestion and Pressure Sensation
In allergy, congestion is fluctuating. Sometimes one side, sometimes both sides close; opening and closing throughout the day is common. Turbinate (concha) hypertrophy may accompany; in this case, nighttime snoring and mouth breathing increase.
In sinusitis, congestion is more persistent and continuous. Pressure in the forehead, around the eyes, and zygomatic area; pain that increases when bending forward and a sensation of facial heaviness can become particularly pronounced during activities such as chewing and climbing stairs. If loss of smell is added to the picture, the possibility of chronic inflammation with impaired drainage at the sinus ostia strengthens.
Clinical note: During examination, I evaluate the edema in the inferior and middle turbinates together with septal deviation. The combination of allergy + deviation can make the patient perceive symptoms more severely than expected; the treatment plan needs to be graded accordingly.
4) When Is Imaging Necessary?
In allergic rhinitis, imaging is not required in most patients. Diagnosis is made through history, physical examination, endoscopy, and allergy tests in appropriate patients. Endoscopic examination to see the effect of allergy inside the nose is a valuable step both for diagnosis and for personalizing treatment.
In sinusitis, endoscopic examination is the first step. Findings such as purulent secretion in the middle meatus, polyps, concha bullosa, paradoxical concha, or anatomical narrowing determine the path we will follow in treatment. Computed tomography comes into play in these situations: complaints that do not improve despite 6–12 weeks of appropriate medical treatment, frequently recurring attacks, suspected polyps, or surgical planning. It is as important to avoid unnecessary CT scans as it is to perform them at the right time with the right sections.
Clinical note: In patients for whom I plan navigation-assisted surgery, an up-to-date and high-resolution CT set significantly increases surgical safety. This difference is particularly felt in revision surgeries.
5) Basic Differences in Treatment Approaches
In allergic rhinitis, the main axis is: avoidance of triggers, nasal corticosteroid sprays, second-generation antihistamines when necessary, and nasal irrigation protocol. Immunotherapy can also be considered with appropriate patient selection. In cases where turbinate hypertrophy is dominant and the symptom burden is high despite medical treatment, I plan function-preserving reduction methods in stages.
In sinusitis, treatment focuses on controlling inflammation and infection in the acute phase: nasal irrigation, timely nasal steroids, and guideline-appropriate antibiotics if there are clinical signs of a secondary bacterial process. In chronic cases, if polyps accompany or anatomical narrowing permanently impairs drainage, endoscopic sinus surgery comes onto the agenda. Surgery opens the natural ostia of the sinuses and cleans diseased tissues; post-surgical regular irrigation and topical steroid protocol significantly reduces the risk of recurrence.
Clinical note: In sinusitis cases accompanied by allergic background, I do not present surgery alone as the “ultimate solution.” Surgery normalizes nasal physiology; if the underlying inflammatory burden is not controlled, recurrence is possible. Therefore, discussing the post-operative care and allergy management plan from the beginning determines the success of treatment.
Situations Where Allergy and Sinusitis Occur Together
In practice, the two often coexist in many patients. Allergic edema narrows the ostia and disrupts mucociliary clearance; this creates grounds for sinusitis. Treating the allergic background can reduce both antibiotic need and surgical requirement. Therefore, a dual strategy is essential: suppressing inflammation and restoring drainage.
Clinical note: In polypoid disease, especially in those with asthma and aspirin sensitivity, medical and surgical approaches need to be planned more meticulously. In this group, regular follow-up and personalized topical steroid irrigation protocols are critically important.
Nasal Irrigation: Seems Simple, Has a Big Impact
Washing done with appropriate solution and technique is the cornerstone in both allergic background and sinusitis. The solution should be warm, the head should be tilted forward with the mouth open; the nasal cavity should be filled not with pressure but with controlled flow. Wrong angle and excessive pressure make posterior drainage difficult and create discomfort.
Clinical note: Providing brief one-on-one application training to the patient after examination significantly increases treatment compliance. I usually schedule it twice a day; three times during intense symptom periods.
Common Mistake About Decongestants and Nasal Steroids
Nasal steroid sprays (mometasone, fluticasone, etc.) are safe when used for a long time and with the correct technique; the spray should be directed into the nose at the correct angle, without hitting the septum, and used regularly. In contrast, the use of congestion-relieving decongestant sprays (oxymetazoline, xylometazoline) for more than 5–7 days causes rebound edema; the patient’s complaint quickly becomes worse. Therefore, the temporary relief it provides at the beginning is misleading.
Clinical note: In cases of rhinitis medicamentosa due to excessive decongestant use, I achieve significant improvement within a few weeks with a controlled cessation protocol and nasal steroid support.
Odontogenic (Dental Origin) Sinusitis: A Topic Not to Be Overlooked
Unilateral thick discharge, tenderness in the upper molar teeth, recent history of root canal treatment, implant, or sinus lift is important. Tooth roots and the maxillary sinus floor are close neighbors; leakage of filling material into the sinus or development of oroantral opening following procedures can cause resistant sinusitis. In this picture, ENT–dentist cooperation is essential; endoscopic cleaning should be managed simultaneously with the dental focus.
Clinical note: In this group, the main factor determining treatment success is complete control of the dental focus. Just cleaning the sinus does not go beyond postponing the problem.
Allergy and Sinusitis in Children
In children, long-term nasal congestion, nighttime snoring, mouth-open sleeping, recurrent cough, and postnasal drip may accompany the picture. Since adenoid (nasopharyngeal tonsil) hypertrophy is common in this age group, evaluation needs to be done according to pediatric age dynamics. Most cases improve with medical treatment; surgical limits need to be well defined and unnecessary interventions avoided.
Clinical approach: In pediatric cases, I keep imaging as limited as possible and perform endoscopic examination with gentle protocols appropriate to age. I provide the family with written simple nasal care and environmental arrangements.
Nasal Complaints During Pregnancy
Pregnancy rhinitis can cause edema in the nasal mucosa due to hormonal effects. Drug selection requires caution during this period; I prefer to prioritize safe, non-drug methods (isotonic irrigation, sleeping in appropriate position, ambient humidity management). When necessary, I establish a coordinated plan with the obstetrician.
My Clinical Approach: Gradual and Person-Specific
1-) Timeline-based, detailed history targeting triggers.
2-) Objective evaluation of nasal anatomy and inflammatory burden with endoscopic examination.
3-) Testing with appropriate panel in case of allergic suspicion; noting accompanying reflux, smoking, occupational exposures.
4-) First medical optimization: irrigation, nasal steroid, antihistamine when necessary; breaking bad habits.
5-) Rational and timely imaging in persistent symptoms.
6-) Endoscopic sinus surgery in anatomical narrowing, polyps, or resistant drainage disorder; structured care and close follow-up after surgery.
7-) This approach significantly reduces unnecessary antibiotic and unnecessary CT rates, while also reducing recurrence risk in cases going to surgery.
Frequently Asked Questions
1-) Does sinusitis turn into allergy?
It doesn’t; however, allergic background increases predisposition to sinusitis. Managing both together reduces relapses.
2-) When should an allergy test be done?
I plan testing for seasonal-recurrent complaints, symptoms lasting more than 3 months, family history of allergy, or persistent congestion despite medical treatment.
3-) How long should I use sprays?
We use nasal steroids for weeks-months according to the physician’s plan. I give decongestants as a short bridge in specific indications, without exceeding 5–7 days.
4-) Does nasal irrigation cause mucosal dryness?
On the contrary, with the right solution and technique, it provides mucosal cleansing and hydration. If there is a sensation of irritation, we review the flow angle and pressure.
5-) When is CT necessary?
When there are chronic symptoms that do not improve in 6–12 weeks despite appropriate treatment, frequent recurrence, suspected polyps, or surgical planning. We do not request CT in most cases at the initial examination.
6-) Is loss of smell permanent?
Generally temporary in allergy, the process may be prolonged in sinusitis. With early endoscopic evaluation, appropriate treatment, and smell rehabilitation, significant improvement is achieved in most patients.
Conclusion: Correct Distinction, Correct Treatment
Although the distinction between allergic rhinitis and sinusitis appears clear on paper, they often overlap in the field. Success in treatment comes with managing triggers, normalizing nasal physiology, and when necessary, permanently establishing drainage through surgery. In my approach, the patient is not a passive follower of the process; they are an active stakeholder who learns and implements care steps. This way, we can reduce unnecessary medication use and relapses.
