A Cold or an Allergy? How Sneezing, Itching and Fever Tell Them Apart

When a runny nose, repeated sneezing and watery eyes appear, many people first think of taking cold medicine. But these symptoms are not always caused by a seasonal infection — what looks like a cold is often in fact an allergic reaction.

The confusion is natural, because both a cold and an allergy affect the nose and the respiratory tract. Their causes, duration and accompanying symptoms, however, are entirely different. Understanding those differences helps people avoid unnecessary medicine and makes it easier to get the right treatment.

The common cold is a viral infection of the upper respiratory tract, and more than 200 viruses can cause it. Symptoms are usually most intense during the first two to three days and then gradually improve. According to specialists, a common cold generally lasts seven to ten days.

An allergy, by contrast, occurs when the body's immune system overreacts to a substance that is normally harmless. Those substances include dust mites, pollen, mould and dead skin cells or hair from pets. Allergic rhinitis can continue for as long as a person remains in contact with the allergen. Depending on what triggers it, the symptoms may be seasonal or may persist throughout the year.

The pattern of sneezing can also reveal the difference. With an allergy, sneezing is often repeated and continuous, especially on contact with dust, pollen or pets. Itching in the nose, throat or eyes is another important sign of allergy. With a common cold, symptoms such as a sore throat, cough and fatigue are more likely to appear.

The type of nasal discharge also deserves attention. A watery, clear discharge lasting several days, especially together with itching and sneezing, may indicate an allergy, and it can continue while the person stays in contact with the allergen. A cold can also cause a runny nose, but as the infection intensifies the nose may become blocked or the mucus may change in thickness. Discharge alone, therefore, cannot confirm whether the problem is an allergy.

Fever and body aches are another important clue. Allergies do not usually cause fever or body aches; those symptoms are generally linked to viral infections. Red eyes and watering alongside nasal itching and repeated sneezing, however, can be a sign of allergic conjunctivitis. When the symptoms appear also matters — if they recur while cleaning the home, in dusty places, around pets or at a particular time of year, that can point to an environmental allergy.

Recurring symptoms should not be dismissed as just an ordinary cold. If sneezing, a blocked nose or watery eyes disrupt sleep and normal daily activities, consulting a doctor is essential. An allergy cannot be identified from symptoms alone, because they can easily be confused with a viral infection or another physical problem. If symptoms persist, especially with no improvement within two weeks, a doctor should certainly be consulted. Medical advice is also needed for breathing difficulty, dehydration and persistent fever; depending on the symptoms and their pattern, doctors may recommend allergy testing or an evaluation. Regular antibiotics should not be taken for a common cold, because antibiotics do not work against viral infections.