As Thailand’s wet season transitions into the hot months, many residents find themselves reaching for tissues—uncertain whether their persistent sneezes, sniffles, and scratchy throats are signs of a lingering cold or responses to the rising pollen count. With research indicating that allergy seasons globally are starting earlier and lasting longer due to climate change, understanding the difference between allergies and the common cold has never been more important—especially for those living in Bangkok and other urban centres prone to increasingly severe air pollution and dense greenery (theguardian.com).
The confusion is understandable. Classic symptoms like nasal congestion, runny nose, sneezing, and even fatigue are common to both colds and seasonal allergies. This overlap often leads individuals to misdiagnose themselves, unwittingly treating the wrong condition or exposing others when they might, in fact, be contagious. According to a prominent physician at Mayo Clinic Family Medicine, “People often get the two confused. In both cases, there is nasal stuffiness, a runny nose and sneezing.” But, as allergy seasons become more intense and unpredictable, especially with warnings of “pollen bombs” in places as far afield as the UK and US, Thai doctors caution this question now matters for more of the year than before.
Why is this distinction crucial for Thais? Not only does misdiagnosis lead to inappropriate treatment, but allergies are on the rise across Thailand. Research conducted in Bangkok shows that the prevalence of allergic rhinitis (AR)—a common form of pollen allergy—has increased markedly, now affecting up to 51% of the city’s population according to some studies (frontiersin.org). This rate is higher than both regional Asia-Pacific and global averages, reflecting both environmental changes and patterns of urbanisation unique to Thailand.
So how does a person distinguish between allergies and a cold? The Bangkok Hospital details tell-tale signs: allergies often present with pronounced itchiness around the eyes, nose, and throat—features less typical in viral infections such as the common cold or flu (bangkokhospital.com). “If you feel like you’re swallowing glass,” one expert noted, “it’s probably a cold.” Kats from the Asthma and Allergy Foundation add that allergy symptoms tend to persist as long as the pollen is present, sometimes lingering for months, while cold symptoms usually resolve within a week.
According to recent clinical research at a major Bangkok hospital, the main environmental offenders are not the pollens seen in the West—like ragweed or birch—but species common to Southeast Asia: Bermuda grass, para grass, and nutsedge (frontiersin.org). Thai patients undergoing allergy testing most often react to these local grasses and weeds, which can be found in parks, roadside verges, and even small neighbourhood gardens across the country. The high year-round pollen presence in the urban air is compounded by Bangkok’s extensive greenery and lack of traditional “pollen seasons,” leaving allergy sufferers few months of true respite.
Environmental and lifestyle factors are also unique drivers in the Thai context. Pet ownership is rising, and with it, household allergens. Meanwhile, studies link air pollution and airborne particulate matter (PM 2.5) to increased allergic sensitization, especially in children.
COVID-19 and flu remain concerns, especially as their respiratory symptoms overlap with allergies and colds. A consultant from a major Bangkok medical centre highlights that allergic reactions do not cause fever—a point that helps in quick triage but is not foolproof. Fever, body aches, and generalised malaise remain more strongly associated with infection than with non-infectious allergic reactions, though both can cause significant fatigue.
The key differences, experts say, can be summarised as follows: allergies trigger itchy eyes and throat; a cold may cause “swallowing glass” soreness. Allergies last as long as the allergen (usually weeks or months), but a cold is self-limited to about 3–7 days in most people. Allergies are not contagious; the common cold is, particularly while sneezing and nasal secretions are present.
In terms of evidence-based treatments for allergies, experts at the Allergy, Asthma and Sinus Center in the United States and Thai hospitals alike recommend a three-pronged approach: avoid known triggers when possible, use non-drowsy antihistamines or steroid nasal sprays, and employ additional measures like saline nasal rinses or eye drops to soothe symptoms. For those with persistent or severe allergies, consultation with an allergist and testing for local pollen reactivity is advised—a step now facilitated by research labs at leading Bangkok universities, which have developed in-house diagnostic kits using extracts from local plants.
Cold treatments, by comparison, rely on symptomatic relief: rest, hydration, and, most importantly, isolating oneself so as not to transmit the infection to family, classmates, or colleagues. Over-the-counter remedies can alleviate symptoms, but only time, rest, and supportive care provide true cure.
For individuals unsure of the cause of their symptoms, newer digital tools are available. Pollen-tracking apps are increasingly accurate, allowing users in Thailand to monitor peak pollen days and modify outdoor activities as needed. For parents and schools, this is particularly valuable given the high rates of AR in children—up to 24% nationwide, with numbers peaking in urban centres during school terms.
Thailand’s challenges, however, extend beyond individual care. Under-identification of allergenic pollen species is a systemic problem. Because imported allergy test kits rarely include Thai pollens, local clinicians have had to develop their own extracts to accurately diagnose patients. Efforts at Siriraj Hospital and other major clinics have resulted in protocols now considered a model for other Southeast Asian nations (frontiersin.org). One Thai hospital director explained, “Routine allergy tests must include extracts from nutsedge, Bermuda, and para grass, which our studies show are the main culprits locally. Only then can we avoid misdiagnosis and better tailor allergy immunotherapy to Thai patients.”
Historically, allergic rhinitis was first characterised in global medical texts as a “Western disease,” but its Asian rise is attributed to a changing climate, increased urban pollution, and evolving indoor lifestyles. Across the last two decades, Thailand’s prevalence rate of allergic rhinitis has doubled in some cohorts—a trend echoed in neighbouring countries but with unique local nuances due to different flora and longer growing seasons.
Looking ahead, rising global temperatures and unpredictable weather are expected to lengthen Thailand’s pollen season further, potentially driving allergy rates even higher. As more people suffer symptoms that persist beyond a week, Thai public health authorities are urging a pragmatic response: better education for the public and health sector, improved access to accurate diagnostic testing for local allergens, and continual monitoring of both pollen and pollution levels.
For Thai readers, the practical recommendation is twofold: if suffering from sneezing, congestion, and watery eyes that persist for weeks, consult with a physician or allergist for possible allergy testing, especially if over-the-counter medications are not effective. Stay tuned to daily pollen reports, limit exposure on high-count days, and wear masks in dusty or pollinated areas—an approach which also mitigates risk during flu and COVID-19 outbreaks. For those with children or a history of asthma, proactive management is essential, as early onset of allergies often predicts more persistent symptoms throughout life.
In short, as Thailand’s seasons shift and the “pollen vs. cold” question grows more complex, staying informed, seeking out local expertise, and taking practical everyday steps are the most effective paths to relief and health.
Sources: The Guardian, Frontiers in Public Health, Bangkok Hospital, Blackmores Thailand, Wikipedia - Pollen Allergy