Is It Allergies or a Cold? Here's How to Tell the Difference

Sneezing, coughing, postnasal drip... It's not always easy to tell the difference between seasonal allergies and colds. "There is quite a bit of overlap in symptoms," says Sanjeev Jain, M.D., a board-certified allergist and immunologist at Columbia Allergy. But learning to tell them apart is key for diagnosis and treatment, which can help your child feel better faster. Here, we break down the causes of allergies and colds in children, with tips for differentiating the symptoms.

Does My Child Have Allergies?

Children get allergies when certain substances (allergens) enter their body, and their immune system produces antibodies and histamine to ward off the threat. This creates an inflammatory response that leads to sneezing, sniffling, itchy eyes, and other allergy symptoms.

Depending on the cause, your kid's allergies can be seasonal or year-round. "Seasonal allergies are often due to an increase in pollen counts of certain plants in your area," says Dr. Jain. Allergy triggers vary by season, but they include weeds, grasses, trees, and some molds. On the other hand, "year-round allergies can often be attributed to indoor allergens such as cat and dog dander, dust mites, mold, and cockroaches," says Dr. Jain.

Symptoms of allergies include:

• Sneezing
• Runny nose with clear, thin mucus
• Nasal and sinus congestion
• Headache
• Postnasal drip
• Mild sore throat
• Coughing (often from postnasal drip)
• Itchy, watery, or red eyes
• Sinus pressure
• Itchy nose
• Worsening of asthma symptoms
• Allergic shiners (dark circles under the eyes)

Note that it's rare for children younger than 3 to have seasonal allergies, so their symptoms probably point to something else.

Does My Child Have a Cold?

Common colds happen when a virus (usually a rhinovirus) enters your body through the eyes, nose, or mouth. "Once the virus is in your body, it replicates until your immune system or medication are able to fight it off," says Dr. Jain. Symptoms usually appear within a few days of exposure to the virus, and they might include:

• Runny or stuffy nose (the mucus could be yellow or green)
• Sore throat
• Low-grade fever
• Cough
• Fatigue
• Congestion
• Muscle aches
• Sneezing
• Mild headache

Allergies or Cold: How to Tell the Difference

Still not sure if your child's symptoms point to allergies or a cold? Here are key differences between them, which can help diagnose your child and get them proper treatment.

Colds are more likely to cause a fever.

Common colds and allergies have some overlap in symptoms, says Dr. Jain. That said, low-grade fever rarely happens with allergies. Headaches, sore throat, and hoarseness are also more common with colds, adds Dr. Jain

Allergy symptoms tend to follow a pattern.

Many patients with allergies have experienced symptoms before. "Symptoms will develop in a pattern, depending on the type of allergen," explains Dr. Jain. "Allergy symptoms caused by outdoor allergens (such as pollen, grasses, trees, and weeds) often occur at the same time each year in a given geographic location." For example, a child with ragweed allergies will experience sneezing, sniffling, and itchy eyes each fall.

That said, "symptoms caused by indoor allergens (such as pet dander, dust mites, and mold) may occur throughout the year," adds Dr. Jain.

Allergies might linger for weeks or months.

Colds typically last for 10-14 days, whereas seasonal allergies can linger for weeks or months (depending on the prevalence of the allergen). "Children under the age of 6 tend to have an average of six to eight colds per year, and older children average two per year," adds Dr. Jain

Exposure to certain substances can worsen allergy symptoms.

Allergy symptoms typically get worse with more frequent exposure to the allergen, and they improve when exposure is reduced. For example, say a child has a dust mite allergy. They'll likely experience sneezing and nasal congestion while inside their home, but the symptoms will improve after spending time in the backyard, says Dr. Jain. Because of this, allergy symptoms can be intermittent and may vary throughout the day and week.

Cold symptoms won't vary much throughout the day.

The viruses that cause colds replicate until your child's immune system (or medication) fights them off. "For this reason, the symptoms are less likely to vary in severity throughout the day or vary vastly from day to day," says Dr. Jain.

Seasonal allergies don't show up in the winter, but colds usually do.

"Common colds are more likely to occur during fall and winter months, where seasonal allergies tend to occur less during the winter," says Dr. Jain. Indeed, seasonal allergies appear most often in the spring, summer, or fall (but indoor allergies might pop up throughout the year).

Allergy symptoms improve with targeted medication.

Allergy medications usually alleviate the symptoms associated with allergies, such as itchy eyes and runny nose. They won't work if your child has a common cold.