The Difference Between Pink Eye and Allergies
Conjunctivitis is an inflammation or infection of the white part of the eye. The inflammation usually extends to the inner lining of the eyelids. Eye redness is a nonspecific symptom that can be caused by an infection or allergies.
Pink eye is an umbrella term, but many people use it to refer to infectious conjunctivitis causes, including viruses, bacteria, and fungi. Infectious conjunctivitis is contagious and is commonly accompanied by other illness signs and symptoms.
Allergies are not contagious. Allergies occur when your immune system overreacts to a benign substance, such as pollen. Chemical exposures and foreign bodies can also cause eye redness.
Differentiating infectious from allergic conjunctivitis is essential to properly treating your condition.
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Pink eye, or conjunctivitis, can refer to anything that causes infection or inflammation of the eye. While “pink eye” is generally used to refer to infectious causes of pink eye, it includes allergic, chemical, autoimmune, or inflammatory causes.
The underlying causes of pink eye can be classified into the following categories:
- Viral conjunctivitis: Over 200 different viral strains cause colds and viral conjunctivitis.1 This highly infectious cause of conjunctivitis spreads easily between people. It can also be spread by touching contaminated objects and in swimming pools.2
- Bacterial conjunctivitis: Bacteria, including Staphylococcus aureus, Streptococcus pneumoniae, Moraxella catarrhalis, and Haemophilus influenza, are common causes of bacterial conjunctivitis. Bacterial conjunctivitis is also highly contagious and commonly spreads via contaminated fingers or objects such as makeup, towels, or contact lenses.
- Allergic conjunctivitis: Seasonal allergies commonly cause eye redness, itching, and tearing.
- Chemical conjunctivitis: Contact with eye irritants such as smoke, chlorine, cleaning supplies, or other fumes can cause irritation and redness.
- Autoimmune: Autoimmune conditions such as Sjogren’s syndrome can cause eye dryness and inflammation.
- Inflammatory conjunctivitis: Foreign bodies and contact lenses can irritate the eye, causing redness and inflammation.
Symptoms associated with pink eye include:
- Pink or red eye color
- Discharge, which varies from clear to yellow-green
- Crusting of the eyelids and eyelashes
- Gritty feeling
- Watery eyes
- A feeling that there is something in your eye
- Swollen eyelids
Pink eye prevention will depend on the cause. To prevent the spread of contagious causes of pink eye, don’t share objects that touch your face, avoid touching your face with unclean hands, and stay away from others when you are sick. Contagious pink eye spreads quickly through schools and daycare centers as children touch objects with unclean hands and spend their day in close contact with other children.
After pink eye resolves, replace your contact lenses and sterilize your contact case. Replace your eye makeup, as the bacteria that cause conjunctivitis can contaminate your makeup and reinfect your eyes.
Pink eye treatment depends on the underlying cause. In many cases, pink eye resolves on its own and only needs symptomatic treatment. If you have pink eye and wear contact lenses, remove your lenses until the infection is clear. Use clean lenses, a sterile case, and a fresh cleaning solution when you resume wearing contact lenses.
- Viral: Viral pink eye treatment involves symptomatic care. Cold compresses reduce swelling and irritation. Saline eye drops moisturize and clean the eye. Some viruses that cause pink eye, such as herpes simplex or varicella-zoster viruses, may require antiviral medications and close follow-up with an eye doctor.
- Bacterial: Bacterial conjunctivitis is treated with antibiotic cream, eye drops, or ointments. Bacterial conjunctivitis typically clears up on its own, but treatment can reduce symptoms and contagiousness.2
- Allergic: Allergic conjunctivitis can be treated with antihistamines, decongestants, mast cell stabilizers, nonsteroidal anti-inflammatory drugs, and steroid eye drops.
- Chemical: Move away from the irritant. Wash your eyes to remove any irritants or chemicals. Call your doctor to see if you should be seen. Some chemicals can cause damage to the eye.
- Autoimmune: Autoimmune conjunctivitis will be treated as part of a comprehensive treatment plan for autoimmune disease.
The various causes of conjunctivitis (pink eye) require very different treatments. Conjunctivitis is easy to recognize but hard to diagnose. The various causes have a wide range of severity, contagiousness, and symptom length. Contact a doctor on the TelegraMD platform to get an online diagnosis and, if appropriate, an online prescription to treat your pink eye.
Allergies are the symptoms you experience when your immune system overreacts to benign substances. The immune system mounts a vigorous defense against pathogens, but it can respond similarly to benign triggers such as pollen, dust mites, and mold allergens.
Allergies are a subset of hypersensitivity reactions. Most specifically, allergies are reactions that activate IgE-binding mast cells. Allergies are common, affecting more than 50 million people each year.
For sensitive people, almost anything can cause an allergic reaction. Common allergens include:
- Pollen: trees, grasses, and weeds
- Dust mites
- Animal dander: proteins found in animal skin cells, urine, and saliva
- Mold spores
- Insect venom
- Foods: peanuts, tree nuts, eggs, wheat, soy, fish and shellfish
- Chemicals: cosmetics, perfumes, cleaning products
- Ear congestion and pain
- Itchy eyes, nose, throat, and sinuses
- Nasal congestion
- Postnasal drip
- Runny nose
More serious allergy symptoms include:4
- Shortness of breath
- Swollen lips and tongue
- Nausea, vomiting, diarrhea
A wide range of substances can trigger allergy symptoms. Depending on what you are sensitive to, reduce your allergy symptoms by:
- Add HEPA filters to vacuums and furnaces to reduce allergens.
- Avoid exposure to foods, chemicals, perfumes, tobacco, and air pollution.
- Check food and drink labels for potential allergens.
- Control pet allergens with frequent bathing, brushing, and grooming.
- Reduce household dust by removing unnecessary carpet, drapes, bedding, and upholstered furniture.
- Encase mattresses and pillows in a zipped plastic, dust-mite-proof encasing.
- Leave your shoes and coats in a mudroom to avoid tracking allergens throughout your home.
- Limit your time spent outdoors.
- Reduce the humidity in your home.
- Stay indoors with your windows closed during high-allergen times. Many weather apps report common allergens and their levels in your area.
- Wash bedding weekly in hot water.
Several prescription and over-the-counter medications are used to treat allergies. According to clinical guidelines, intranasal steroids are the first-line treatment for anyone with allergy symptoms that are severe enough to impact their quality of life.
Second-generation antihistamines are a good option if you have itching, watery eyes, and sneezing. Second-generation antihistamines such as cetirizine and loratadine are less sedating than first-generation antihistamines.
Decongestants can relieve nasal congestion and sinus headaches, but they must be used carefully as they can increase blood pressure and aggravate heart-related medical conditions. Talk to your doctor if you need to use a decongestant for more than a few days.
When To Seek Help from a Healthcare Professional
Signs and symptoms that suggest that you should see a doctor to evaluate your conjunctivitis include:
- Eye pain
- Sensitivity to light
- Pain when moving your eye
- Redness or swelling that involves the eyelid or extends out from the eye
- Symptoms that worsen or don’t improve
- Bacterial conjunctivitis that does not respond within 24 hours
- Blisters or vesicles near the eye
If you have a weakened immune system, it is always a good idea to contact your doctor if you have an infection. Your signs and symptoms may be atypical and need specialized treatment.
While we strive to always provide accurate, current, and safe advice in all of our articles and guides, it’s important to stress that they are no substitute for medical advice from a doctor or healthcare provider. You should always consult a practicing professional who can diagnose your specific case. The content we’ve included in this guide is merely meant to be informational and does not constitute medical advice.
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2. Azari AA, Barney NP. Conjunctivitis: A Systematic Review of Diagnosis and Treatment. JAMA. 2013;310(16):1721-1730. doi:10.1001/jama.2013.280318
3. Beard S. Rhinitis. Prim Care. Mar 2014;41(1):33-46. doi:10.1016/j.pop.2013.10.005
4. Wallace DV, Dykewicz MS. Seasonal Allergic Rhinitis: A focused systematic review and practice parameter update. Curr Opin Allergy Clin Immunol. Aug 2017;17(4):286-294. doi:10.1097/aci.0000000000000375