Longer pollen seasons set to make allergies a major public health issue in coming decades

In an interview conducted at the UV's Faculty of Medicine and Dentistry, where he teaches, the specialist explains that one of the most visible changes is the lengthening of pollination seasons, which extends the time of exposure to allergens for sensitised individuals. "If the season lasts longer, plants produce pollen for more weeks and increase the overall allergen load in the environment," he notes.

Environmental changes are altering the behaviour of plants and other allergens. Rising temperatures, higher concentrations of carbon dioxide and urban pollution are stimulating plant growth and prolonging pollen production, thereby extending the duration of exposure for allergy sufferers.

Furthermore, plants may modify their proteins in response to these new environmental conditions as a means of adaptation. According to Montoro, these alterations can generate proteins that are more aggressive from an allergenic standpoint, resulting in more severe symptoms.

Even lesser-known factors, such as light pollution, influence the biological cycles of plants by disrupting their circadian rhythms and prolonging their metabolic activity, as several studies have already demonstrated.

An emerging public health concern
The specialist warns that if prevalence continues to rise, allergies could become a significant public health problem – not only due to the disease burden on patients, but also because of its social and even economic repercussions.

Allergic symptoms affect quality of life and can lead to absenteeism or reduced productivity at work, as well as increasing healthcare expenditure associated with pharmacological treatments and vaccines.

However, addressing the environmental factors driving the rise in allergies requires long-term measures, such as reducing pollutants or introducing changes in urban planning and the management of less allergenic plant species in parks and public gardens. "These changes do not produce immediate results – their effects are felt over the medium to long term – but they must be set in motion as soon as possible", he adds.

Cold or allergy: how to tell the difference
One of the most common sources of confusion among patients is distinguishing between a common cold and a respiratory allergy. In Montoro's words, the duration and nature of symptoms offer "important clues".

While a cold typically lasts between five and seven days, allergy symptoms can persist for weeks or even months. Allergy is also characterised by itching in the nose, eyes or throat, repeated sneezing and a clear nasal discharge – in contrast to respiratory infections, where secretions tend to be thicker and yellowish or greenish in colour.

Another key difference is that allergies are not usually accompanied by fever or general malaise, which are common features of infectious conditions.

The most common manifestations of allergic disease are respiratory in nature, particularly rhinitis and bronchial asthma, owing to the constant exposure of the airways to environmental particles – primarily from plants (grasses, cypress and conifers in general, olive trees, banana trees, pellitory, and others are particularly harmful) – as well as dust mites, animal epithelia and moulds, the latter being responsible for year-round symptoms.

"It is important to bear in mind that most of our patients are allergic to more than one allergen source – that is, to mites, moulds and pollen; mites and pollen; or mites and animal epithelia. This makes it difficult to treat and control allergic respiratory disease. Allergen-specific immunotherapy (the allergy vaccine) is becoming increasingly necessary," he stresses.

In this regard, Montoro recommends careful consideration of the types of vegetation – always necessary – used in urban and ornamental spaces, in order to minimise allergic reactions. He notes, for example, that the orange tree produces heavy, sticky pollen that does not travel far but simply remains where it lands, unlike olive or cypress pollen, which is light and remains suspended in the air for much longer.

To monitor pollen levels in the atmosphere, the province of Valencia has two monitoring stations: one at the Clinical Hospital (on Avenida de Blasco Ibáñez) and another in Xàtiva. According to Javier Montoro, the coverage radius of these stations is sufficiently wide to provide useful warnings to allergy sufferers. Air quality information can also be followed – with approximately a week's delay – via the website of the Valencian Association of Allergology and Clinical Immunology, which also features a range of recommendations to help allergy sufferers cope during this season.

A scientific forum to advance knowledge on asthma
Dr Montoro Lacomba is also driving scientific initiatives to improve understanding of allergic disease. On 13 and 14 March, the seventh edition of the AsmaDual symposiumwill take place – a forum he co-organises with pulmonologist Fernando Sánchez Toril, which will bring together specialists from all over Spain and Latin America.

The event, which will be held in a hybrid format combining in-person and online participation, will cover topics including the most innovative biological therapies for asthma, allergen immunotherapy and the influence of the exposome – the totality of environmental factors surrounding an individual – on respiratory diseases.

Montoro highlights that gatherings of this kind make it possible to integrate knowledge from different disciplines and advance early diagnosis and treatment of complex respiratory conditions.

The expert also underlines the importance of science communication and the role of the media in improving public health awareness: "Media coverage can help many patients identify their condition and seek specialist care", he concludes.