Seasonal and Perennial Allergic Rhinitis

 

Allergic rhinitis is one of the most common chronic conditions, affecting approximately 1 to 3 in 10 adults and more than 4 in 10 children worldwide. It is a non-infectious inflammation of the nasal mucosa caused by an exaggerated immune response to airborne allergens such as pollen, house dust mites, and animal dander. When exposed to these allergens, immune cells are activated and release histamine and other inflammatory substances, resulting in vasodilation (widening of the blood vessels) and swelling of the nasal mucosa. This swelling, together with irritation of nerve endings and increased mucus production, contributes to the characteristic feeling of nasal congestion or a “blocked nose” commonly experienced by patients with allergic rhinitis.

In clinical practice, allergic rhinitis is classified according to when symptoms occur and their severity. Seasonal allergic rhinitis occurs during specific periods of the year and is mainly caused by pollen from trees (such as olive and cypress), grasses, and weeds (such as Parietaria). In contrast, perennial allergic rhinitis persists throughout the year and is associated with allergens such as house dust mites, moulds, and pet dander, particularly from cats and dogs.

Depending on the frequency of symptoms, allergic rhinitis can also be classified as intermittent (symptoms occurring fewer than 4 days per week or for fewer than 4 consecutive weeks per year) or persistent (symptoms occurring more than 4 days per week and for more than 4 weeks). Finally, according to the impact of symptoms on the patient’s daily life, allergic rhinitis may be classified as mild, moderate, or severe.

Typical symptoms include paroxysmal sneezing (repeated episodes of sneezing), clear nasal discharge, intense nasal itching, and nasal congestion. Allergic conjunctivitis frequently occurs at the same time, causing excessive tearing, redness, and itching of the eyes. Patients may also experience postnasal drip (mucus draining towards the throat), coughing, and dry mouth due to the need to breathe through the mouth. In some cases, dark circles may develop under the eyes as a result of chronic venous congestion associated with impaired nasal breathing.

In addition, a significant proportion of patients with pollen allergy may develop pollen-food allergy syndrome (PFAS), also known as oral allergy syndrome (OAS). This condition causes itching or swelling in the mouth after eating certain raw fruits, vegetables, or nuts containing proteins that are structurally similar to proteins found in pollen.

Allergic rhinitis is often confused with the common cold or non-allergic rhinitis, but there are important differences. The common cold is a viral infection that is often accompanied by fever, fatigue, muscle aches, and thicker nasal secretions, with symptoms usually resolving within 5–10 days. In contrast, allergic rhinitis does not cause fever and persists for as long as exposure to the responsible allergen continues. Itching inside the nose is also a particularly characteristic symptom.

If allergic rhinitis remains undiagnosed or inadequately treated, it may contribute to the development of associated conditions such as chronic sinusitis, nasal polyps, and otitis media with effusion in children. In addition to causing sleep disturbances, allergic rhinitis is also associated with an increased risk of developing allergic asthma, which affects the lower respiratory tract and may cause symptoms such as coughing, shortness of breath, and wheezing.

An accurate diagnosis can be established at the allergy clinic through skin prick tests, a quick and virtually painless procedure that provides results within just 15–20 minutes, or through specific blood tests measuring allergen-specific IgE antibodies.

Treatment is always tailored to the individual patient and may include second-generation antihistamines, which generally cause little or no drowsiness, to control sneezing, itching, and nasal discharge. At the same time, intranasal corticosteroids (nasal sprays) are among the most effective treatments for reducing inflammation and nasal congestion.

Particular caution is required with commercially available decongestant nasal sprays containing vasoconstrictor agents. Excessive use for more than 3–5 days may lead to rhinitis medicamentosa (rebound congestion), a condition in which the nasal mucosa becomes increasingly swollen once the effect of the medication wears off, leading to repeated and potentially prolonged use.

Finally, the only disease-modifying treatment that goes beyond temporary symptom relief and targets the underlying allergic response is Allergen-Specific Immunotherapy (AIT), also known as desensitisation. Through the regular administration of controlled amounts of the responsible allergen—either sublingually as drops or tablets (SLIT) or through subcutaneous injections (SCIT)—the immune system is gradually trained to develop tolerance to that allergen.

Allergen immunotherapy can provide long-term improvement in symptoms, substantially reduce the need for medication, and may reduce the risk of progression from allergic rhinitis to asthma in appropriately selected patients.

If you experience persistent or recurrent nasal symptoms, an allergy assessment is an important first step towards identifying the underlying cause and restoring your quality of life.

Do you have symptoms consistent with allergic rhinitis? Contact our clinic to schedule your appointment.