Nasal Irrigation During Rhinitis: Controversies and Evidence
Why do physicians recommend nasal irrigation for patients with infectious or allergic rhinitis or rhinosinusitis? Is this simply advice, or is there evidence that nasal mucosal care influences the course of the disease and helps prevent complications of rhinitis? How does nasal irrigation affect the nasal mucosa? Is it safe? Based on guidelines for the treatment of rhinitis and rhinosinusitis and other published articles, the information presented here on nasal irrigation with seawater addresses questions regarding its indications, effectiveness, and safety.
It is well known that viral rhinitis occurs more frequently in both children and adults during the colder months. Treatment of rhinitis is an ongoing process because rhinitis associated with viral inflammation of the upper respiratory tract lasts for several days. In adults, rhinitis may persist for up to a week, while children experience it more frequently and for longer periods and have a greater risk of complications.
Initially, the nasal mucosa becomes swollen, red, and irritated. This may last for up to 3 days. Subsequently, as the immune response becomes more active, clear nasal discharge develops while nasal congestion persists. The secretions may thicken and further impair nasal breathing. At this stage, there is a so-called turning point: rhinitis either begins to subside and resolves or a complication develops, such as otitis media, rhinosinusitis, or inflammation of the lower respiratory tract.
It is important to consider the physiological characteristics of the nasal mucosa. This helps explain how inflammation affects anatomical structures and their functions. The nasal mucosa consists of respiratory epithelium that extends into the lower respiratory tract. Therefore, many scientific studies investigating pathological changes in the lower respiratory tract can also be applied to physiological changes in the nasal mucosa.
The mucosa is covered by a layer consisting of two components: a superficial mucus layer (gel) and an underlying periciliary or serous layer (sol), which contains proteins, peptides, and macrophages with protective and antibacterial properties. The cilia of the superficial mucosal cells extend into this layer. As the cilia move, they propel the superficial mucus layer toward the nasopharynx. This process is known as mucociliary clearance.
As a result, inhaled microparticles, allergens, fungal spores, and bacterial and viral colonies do not remain on the nasal and nasopharyngeal mucosa and cause inflammation. The mucus “carpet,” together with pathogens, is transported into the stomach, where potential pathogens are neutralized by gastric acid. This is the primary cleansing function of the nasal mucosa. The mucosa also warms and humidifies inhaled air. Even olfactory function depends on mucosal moisture and mucus structure.
Changes in the rate of mucociliary clearance and impaired ciliary movement, whether slowed or accelerated, compromise the protective function of the nasal mucosa. The most common cause is a simple viral inflammatory process—acute rhinopharyngitis or the common cold. In response to infection, the nasal mucosa increases inflammatory cell activity and secretion. The virus adversely affects the rate of mucociliary clearance.
The thickness of the superficial periciliary layer (sol) is important. Under normal conditions, it is approximately 7 μm. If this layer becomes thinner, movement of the cilia slows and they are unable to move the superficial gel layer effectively, resulting in large accumulations of mucus containing pathogens. Bacterial colonies may additionally damage the cilia of superficial mucosal cells and produce enzymes that inhibit ciliary movement. This further reduces the rate of mucociliary clearance.
Table 1. Recommendations and Evidence for the Treatment of Acute Rhinosinusitis in Adults (3)
| Treatment | Level of Evidence | Grade of Recommendation | Application |
|---|---|---|---|
| Antibiotics | Ia | A | Yes, acute bacterial rhinosinusitis |
| Topical steroids | Ia | A | Yes, mostly viral acute rhinosinusitis |
| Topical steroids plus antibiotics | Ia | A | Yes, acute rhinosinusitis |
| Oral steroids plus antibiotics | Ia | A | Yes, acute rhinosinusitis |
| Nasal irrigation | Ia | A | Yes |
| Combination of an antihistamine and a decongestant | Ia | A | Yes, acute rhinosinusitis |
After viral inflammation, mucociliary clearance may remain impaired for 6–12 weeks. Patients most commonly complain of persistent, troublesome nasal secretions, a sensation of congestion, and prolonged rhinitis. This is where the effect of nasal irrigation on mucociliary clearance and the benefits of saline solutions become relevant. Depending on their osmolarity (salinity), saline solutions increase the thickness of the periciliary layer (sol), thereby increasing the rate of mucociliary clearance and improving the mucosa’s cleansing function. This prevents pathogens from remaining on the mucosa, improves nasal breathing, and reduces symptoms of rhinitis (2).
Figure 2. Effect of an Isotonic Seawater Preparation on the Incidence of Acute Upper Respiratory Tract Infections and the Number of Complications and Missed School Days (1)
| Outcome | Control Group | Treatment Group* | Reduction |
|---|---|---|---|
| URTI episodes | ~52 | ~22 | 59% |
| Missed school days due to URTI | ~25 | ~9 | 65% |
| URTI complications | ~14 | ~4 | 70% |
Treatment group: prophylactic use of isotonic seawater.
Study duration: 3 weeks of acute treatment followed by 9 weeks of prophylactic treatment – 12 weeks in total.
Study participants: 401 children aged 6–10 years.
Study objective: To evaluate the effect of isotonic seawater on the incidence of URTIs and the number of complications and missed school days
Medical literature increasingly includes new articles examining the effect of nasal irrigation on treatment effectiveness. Nasal irrigation is one of the therapeutic measures included in guidelines for the treatment of acute rhinosinusitis (3), is used to relieve symptoms of allergic rhinitis (4), and may help prevent complications of rhinitis in children (1).
Because of age-related characteristics of immune system development, complications of rhinitis occur more frequently in preschool and early school-age children than in adults. The beneficial effects of nasal irrigation have been investigated specifically in this age group. According to I. Slapak (1), prevention of rhinitis complications in children could be achieved through nasal irrigation alone or in combination with other treatments. The article concluded that there was a statistically significant reduction in the incidence of rhinitis complications, the frequency of antibacterial drug use, and the number of missed school days (1).
It is also noted that even prophylactic use of seawater and other cold-related treatments in preschool and younger school-age children may reduce the frequency of recurrent illnesses during the colder months.
Treatment of rhinitis is selected according to the predominant symptoms. For example, if nasal congestion is present, reducing mucosal swelling is appropriate. In cases of abundant clear secretions, measures that reduce nasal mucosal secretion are used, whereas thick secretions that are difficult to blow out or remove require mucus-thinning measures.
Treating complications of rhinitis requires greater attention, additional medical supervision, and time. Nasal irrigation has long been known as a method of treating rhinitis. Rinsing accumulated secretions from the nasal cavity reduces the likelihood of viral pathogens becoming established and multiplying and decreases the risk of local inflammation. In addition, seawater moisturizes the nasal mucosa, reduces swelling, thins thick mucus, and helps remove secretions that interfere with nasal breathing (5).
Nasal irrigation is safe when performed according to instructions. Only minor adverse reactions have been described, including local irritation, itching, and a burning sensation (2). Nasal irrigation is not recommended only in the following situations (6): facial and head trauma, because the solution may enter post-traumatic cavities, and musculoskeletal disorders accompanied by neurological symptoms, because severe tremor may increase the risk of aspiration.
