Am I sick, or is it allergies?

Overview

As the saying goes, “Know thy enemy.” When it comes to distinguishing between a common cold and allergies, understanding the symptoms is critical. A cold typically includes a sore throat, body aches, and a runny or stuffy nose with thicker mucus, usually lasting about a week. Allergies, however, are caused by triggers like pollen, dust, or pet dander and bring symptoms such as itchy eyes, a clear runny nose, and sneezing, which can persist as long as the allergen is present. Seasonal patterns often indicate allergies. In this article, you’ll learn to distinguish between a common cold and allergies by understanding their key symptoms and triggers.

What do allergies feel like?

Allergy symptoms vary depending on the substance involved and can impact different body parts, including airways, sinuses, nasal passages, skin, and the digestive system. Allergic reactions can be mild or severe, with some cases leading to a life-threatening condition called anaphylaxis.

“If you know what you have, you won’t take medications that you don’t need, that aren’t effective, or that might even make your symptoms worse,” says NIH’s Dr. Teresa Hauguel, an expert on infectious diseases that affect breathing.

Distinguishing between respiratory allergies and the common cold can be difficult, as they share several symptoms. However, there are some key differences that can help identify each condition:

Respiratory Allergies

Respiratory allergies often present with various symptoms that can significantly impact daily life. Sneezing is frequent and often occurs in rapid succession. A runny or stuffy nose with clear, watery nasal discharge is common, along with hallmark symptoms such as itchy eyes, nose, or throat. Watery eyes, often accompanied by redness, and postnasal drip, which can lead to a sore throat, are also typical. Fatigue can occur, though it is usually less severe than what is experienced with a cold. Coughing is generally dry, and wheezing or shortness of breath may be present in cases of allergic asthma. The characteristics of respiratory allergies include symptoms that persist as long as there is exposure to the allergen, which can be for weeks or even months. Symptoms can start almost immediately after contact with the allergen and are often seasonal, depending on the specific allergen, such as pollen in the spring.

Common Cold

The common cold presents with various symptoms that can make daily activities challenging. Sneezing is common, though typically less frequent than with allergies. A runny or stuffy nose starts with a watery discharge but can become thicker and yellow or green as the cold progresses. A sore throat is a common early symptom, and coughing can be either dry or productive (mucus-producing). Fatigue is often more pronounced with a cold compared to allergies. A mild fever may occur, especially in children, and mild body aches can also be present, though these are more commonly associated with the flu. The duration of a common cold is usually 7-10 days. The onset is gradual, with symptoms developing over a day or two. Colds are more common in winter and fall but can occur year-round.

A comparison table between respiratory allergies and the common cold:

Based on symptoms and characteristics, this table helps distinguish between respiratory allergies and the common cold.

What causes allergies and colds?

Seasonal allergies and colds are common conditions affecting millions of people but have distinct causes. Seasonal allergies, often triggered by pollen, mold spores, dust mites, or pet dander, occur when the immune system overreacts to these harmless substances. On the other hand, common colds are caused by viruses, primarily rhinoviruses, which spread through direct contact and airborne transmission.

“For the past few years, because of the pandemic, any sniffle was grounds for a health appointment or staying away from your loved ones,” said Elena N. Zamora, MD, MHA, a family medicine doctor at UT Physicians. 

Causes of Seasonal allergies

These are primarily caused by the body’s immune system reacting to airborne substances that are typically harmless. These substances, known as allergens, can trigger an allergic response during certain times of the year when they are more prevalent in the environment. Common causes of seasonal allergies include:

• Pollen: Trees and grass lead to pollen during their respective pollination periods. For example, tree pollen is common in the spring, weed pollen and grass pollen in the summer in the late summer and fall.
• Mold Spores: Mold thrives in damp, humid environments and releases spores into the air, particularly during the fall and spring seasons.
• Dust Mites: These tiny creatures can become more prevalent in the home during the fall and winter when the indoor heating is on, leading to increased exposure.
• Pet Dander: While pet dander can be a year-round allergen, it can become more problematic during seasonal changes when pets shed their coats.

Causes of Colds

The common cold is caused by viruses, with the rhinovirus being the most common culprit. Other viruses that can cause colds include coronaviruses, adenoviruses, and respiratory syncytial virus (RSV). While bacterial infections can sometimes develop as secondary infections (e.g., sinusitis or ear infections) following a viral cold, the initial cause of the common cold is always viral.Colds can be contagious and can spread easily from person to person through several mechanisms::

• Direct Contact: Shaking hands or touching surfaces contaminated with cold viruses (like doorknobs, keyboards, or phones) and then touching the face, especially the nose or mouth.
• Airborne Transmission: Inhaling respiratory droplets from an infected person who coughs or sneezes.
• Close Personal Contact: Spending time in close proximity to someone who has a cold, particularly in enclosed spaces like offices, schools, or public transportation.

Can allergies be mistaken for cold?

Allergies and colds can often be confused due to their overlapping symptoms, such as sneezing, nasal congestion, and fatigue. However, key differences can help differentiate between the two. Allergies frequently cause itching in the eyes, nose, or throat, which is uncommon in colds. Nasal discharge in allergies is typically clear and watery, while colds often start with clear mucus that becomes thicker and changes color. Allergies can last for weeks or months as long as exposure to allergens persists, whereas cold symptoms usually resolve within 7-10 days. Allergies tend to cause symptoms quickly upon exposure to triggers like pollen or dust mites, whereas cold symptoms develop gradually over a day or two. Additionally, allergies rarely result in fever or body aches, which are more typical of colds. Proper diagnosis and treatment hinge on these distinctions: allergies are managed with antihistamines and avoiding allergens, while colds are treated with rest, hydration, and over-the-counter medications.

When to consult a doctor?

Consulting a doctor is important when certain symptoms or conditions arise, ensuring proper diagnosis and treatment. 

• Severe Reactions: Swelling of face, lips, or throat; difficulty breathing; severe rash.
• Persistent Symptoms: Symptoms lasting several weeks without relief from over-the-counter medications.
• New Symptoms: Development of fever, sinus pain, or thick, colored nasal discharge.
• High Fever: A fever above 100.4°F (38°C) that lasts more than a few days or recurs after disappearing.
• Severe Symptoms: Significant chest pain, difficulty breathing, persistent coughing.
• Prolonged Illness: Symptoms lasting more than 10 days without improvement.
• Recurring Infections: Frequent colds or respiratory infections.
• Underlying Conditions: Worsening symptoms with chronic health issues (e.g., asthma, diabetes, heart disease).
• Vulnerable Groups: Young children, older adults, and pregnant women with severe or persistent symptoms.

FAQs about allergies vs cold