Pink Eye vs Allergies: Which One Is it?

When your eyes become red, itchy, or watery, it’s easy to assume it’s just allergies, but those same symptoms could also point to pink eye. Knowing the differences between pink eye vs allergies is important for proper treatment and prevention of spreading infection. We’ll break down the symptoms, appearance, causes, and treatments of each and discuss when to visit a medical professional.

Root Causes of Pink Eye vs Allergies

Even though they both present similarly the causes of pink eye vs allergies are completely different. Pink eye is usually caused by a viral or bacterial infection, making it highly contagious, especially in schools and workplaces. 

Viral Causes of Pink Eye

Viral conjunctivitis is the most common and contagious form. It often accompanies a cold or respiratory infection.

• Adenoviruses: The most common viral cause. These can also lead to pharyngoconjunctival fever (with sore throat, fever, and red eyes) or epidemic keratoconjunctivitis (a more severe form with corneal involvement).

• Herpes Simplex Virus (HSV): Can cause more serious eye infections, sometimes with painful sores on the eyelid.

• Varicella-Zoster Virus (chickenpox/shingles): May affect the eye in shingles affecting the face.

• Enteroviruses (especially Enterovirus 70 and Coxsackievirus A24): Associated with acute hemorrhagic conjunctivitis.

  
  

Bacterial Causes of Pink Eye

Bacterial conjunctivitis is more common in children and usually causes thicker, yellow or greenish discharge (more on that later).

• Staphylococcus aureus: Common in adults.

• Streptococcus pneumoniae: Often affects children.

• Haemophilus influenzae: A common cause in kids; may be part of ear and respiratory infections.

• Moraxella catarrhalis: Especially in children with ear infections.

• Neisseria gonorrhoeae: Can cause a severe, sight-threatening infection, especially in newborns (ophthalmia neonatorum).Chlamydia trachomatis: Causes inclusion conjunctivitis in sexually active individuals and trachoma (a leading cause of blindness globally).

  
  

Causes Of Allergic Conjunctivitis

Redness, itching, and swelling caused by allergies is also called allergic conjunctivitis. It is typically caused by environmental allergens that trigger an autoimmune response that leads to inflammation. Allergic conjunctivitis can be further broken down into seasonal allergic conjunctivitis (SAC) or perennial allergic conjunctivitis (PAC):

Seasonal (linked to hay fever):

• Pollen from trees, grasses, and weeds (especially in spring and fall)

• Often accompanied by sneezing, runny nose, or nasal congestion (allergic rhinitis)

  
  

Perennial (year-round):

• Dust mites

• Pet dander (especially from cats and dogs)

• Mold spores

• Cockroach allergens

  
  

Appearance of Pink Eye vs Allergic Conjunctivitis

Again, both pink eye and allergies may present as red, swollen, and itching. But they do look different if you know what to watch out for. Pink eye is so called because the redness is marked and often covers the entire sclera (white part of the eye). The redness is usually worse with viral infections vs bacterial. With the latter, discharge can be so thick and sticky that sufferers wake up with eyelids stuck together and physically have to pull them apart. 

Allergy eyes may also appear pink, but it is generally not as bad as with viral or bacterial conjunctivitis. They may be watery, but discharge is quite rare with allergies. 

As you can see in the image above, the appearance of each type of conjunctivitis is quite similar (especially between viral and allergic conjunctivitis). It is also important to note that you can, in fact, have more than one issue affecting your eyes. That is to say, you may have both a bacterial and viral infection, or you may have an infection and allergies.

Furthermore, certain cases of redness or swelling can be due to another condition entirely. Shingles, iritis, keratitis and even glaucoma can mimic symptoms of allergies and pink eye and will require a referral to a specialist. This is why it is important to seek in-person medical treatment as soon as possible to ensure you receive proper diagnosis and treatment. 

Can Allergies Ever Affect Just One Eye?

While allergic conjunctivitis typically affects both eyes, it can begin in or be more severe in one eye if an allergen comes into direct contact with it, like rubbing one eye after touching a dog or cat. However, persistent symptoms in one eye may point more toward pink eye or another condition.

What Is the Treatment for Pink Eye vs Allergies?

Pink eye treatment usually requires a prescription, while allergic conjunctivitis treatment can be found over the counter.

Pink Eye Treatment

• Viral: Typically resolves on its own; cool compresses and lubricating drops can relieve discomfort.

• Bacterial: May require antibiotic eye drops or ointments.

  
  

Allergic Conjunctivitis Treatment

• Place a cold compress on your eyes

• Flush eyes with water

• Artificial tears

• Antihistamines 

  
  

Should You Go to Urgent Care for Pink Eye?

If you’re unsure whether you have pink eye or allergies, or if you have severe symptoms, eye pain, changes in vision, or thick discharge, you should visit an urgent care center or same-day walk in clinic. Prompt diagnosis and treatment can prevent complications and stop contagious infections from spreading.

Of course, allergies can be just as debilitating as a pink eye infection, interfering with our work, sleep, and ability to complete daily tasks. If your allergies are severe and/or persistent, this may also warrant a visit to urgent care or a walk in clinic. At Midwest Minor Medical, we offer allergy shots for common environmental allergens to give you lasting relief without the drowsiness and other side effects of oral antihistamines. 

Walk In Clinic Omaha

Our walk in clinic in Omaha offers convenient and affordable care for eye infections, allergies, cuts, and other non-emergent medical issues. We pride ourselves on efficiency without sacrificing quality of care. If you or a loved one is in need of care now, visit our clinic today-no appointment needed!