What is the difference between pink eye and allergy eyes

Red eye, swelling of the conjunctiva, and watering of the eyes are symptoms common to every forms of conjunctivitis. However, the pupils should be normally reactive, and the visual acuity normal.

Conjunctivitis is identified by irritation and redness of the conjunctiva.

What is the difference between pink eye and allergy eyes

Except in obvious pyogenic or toxic/chemical conjunctivitis, a slit lamp (biomicroscope) is needed to confirm the diagnosis. Examination of the eyelid conjunctiva is generally more diagnostic than examination of the scleral conjunctiva.


Viral conjunctivitis is often associated with an infection of the upper respiratory tract, a common freezing, or a sore throat. Its symptoms include excessive watering and itching. The infection generally begins in one eye, but may spread easily to the other eye.

Viral conjunctivitis manifests as a fine, diffuse pinkness of the conjunctiva, which is easily mistaken for a ciliary infection of the iris (iritis), but corroborative signs on microscopy, particularly numerous lymphoid follicles on the tarsal conjunctiva, and sometimes a punctate keratitis are seen.


Allergic conjunctivitis is inflammation of the conjunctiva due to allergy.[5] The specific allergens may differ among patients. Symptoms result from the release of histamine and other athletic substances by mast cells, and consist of redness (mainly due to vasodilation of the peripheral little blood vessels), swelling of the conjunctiva, itching, and increased production of tears.

What is the difference between pink eye and allergy eyes


Bacterial conjunctivitis causes the rapid onset of conjunctival redness, swelling of the eyelid, and a sticky discharge. Typically, symptoms develop first in one eye, but may spread to the other eye within 2–5 days. Conjunctivitis due to common pus-producing bacteria causes marked grittiness or irritation and a stringy, opaque, greyish or yellowish discharge that may cause the lids to stick together, especially after sleep. Severe crusting of the infected eye and the surrounding skin may also happen. The gritty or scratchy feeling is sometimes localized enough that patients may insist that they own a foreign body in the eye.

Common bacteria responsible for nonacute bacterial conjunctivitis are Staphylococcus, Streptococcus,[6] and Haemophilus species.

What is the difference between pink eye and allergy eyes

Less commonly, Chlamydia spp. may be the cause.[7]

Bacteria such as Chlamydia trachomatis or Moraxella spp. can cause a nonexudative but persistent conjunctivitis without much redness. Bacterial conjunctivitis may cause the production of membranes or pseudomembranes that cover the conjunctiva. Pseudomembranes consist of a combination of inflammatory cells and exudates and adhere loosely to the conjunctiva, while true membranes are more tightly adherent and cannot be easily peeled away.

What is the difference between pink eye and allergy eyes

Cases of bacterial conjunctivitis that involve the production of membranes or pseudomembranes are associated with Neisseria gonorrhoeae, β-hemolytic streptococci, and Corynebacterium diphtheriae. C. diphtheriae causes membrane formation in conjunctiva of unimmunized children.[8]


Chemical eye injury may result when an acidic or alkaline substance gets in the eye.[9] Alkali burns are typically worse than acidic burns.[10] Mild burns produce conjunctivitis, while more severe burns may cause the cornea to turn white.[10]Litmus paper may be used to test for chemical causes.[9] When a chemical cause has been confirmed, the eye or eyes should be flushed until the pH is in the range 6–8.[10] Anaesthetic eye drops can be used to decrease the pain.[10]

Irritant or toxic conjunctivitis is primarily marked by redness.

If due to a chemical splash, it is often present in only the lower conjunctival sac. With some chemicals, above every with caustic alkalis such as sodium hydroxide, necrosis of the conjunctiva marked by a deceptively white eye due to vascular closure may happen, followed by sloughing off of the dead epithelium. A slit lamp examination is likely to show evidence of anterior uveitis.


Inclusion conjunctivitis of the newborn is a conjunctivitis that may be caused by the bacterium Chlamydia trachomatis, and may lead to acute, purulent conjunctivitis.[11] However, it is generally self-healing.[11]

Conjunctivitis Symptoms, Causes, and Treatments

By Gary Heiting, OD

Conjunctivitis Treatments

As you would expect, the treatment of pink eye depends on the type of conjunctivitis you have:

  1. Viral conjunctivitis treatment In most cases, viral conjunctivitis will run its course over a period of several days and no medical treatment is required.

    What is the difference between pink eye and allergy eyes

    Applying a freezing, wet washcloth to the eyes several times a day can relieve symptoms of viral conjunctivitis.

  1. Bacterial conjunctivitis treatment Your eye doctor typically will prescribe antibiotic eye drops or ointments for the treatment of bacterial conjunctivitis.
  1. Allergic conjunctivitis treatment Allergy medications often can assist prevent or shorten bouts of allergic conjunctivitis.

Often it can be hard to tell the type of conjunctivitis you own by symptoms alone.

What is the difference between pink eye and allergy eyes

Also, sometimes other eye or health conditions may be causing your pink eye symptoms.

Conditions associated with conjunctivitis include dry eyes. Also, bacterial conjunctivitis sometimes can lead to extremely serious eye problems potentially causing permanent vision loss.

For these reasons, anytime you develop red, irritated eyes, you should call an eye doctor immediately and schedule an eye exam.

If you wear contact lenses and own red, irritated eyes, remove your lenses and wear only your spectacles until your eye doctor has had a chance to examine your eyes.

Common Conjunctivitis Symptoms

The primary symptom of pink eye is an eye that has a pink appearance.

Other symptoms of pink eye depend on the type of conjunctivitis:

  1. Viral conjunctivitis symptoms include watery, itchy eyes or sensitivity to light. One or both eyes can be affected. Viral conjunctivitis is highly contagious and can be spread by coughing and sneezing.
  1. Bacterial conjunctivitissymptoms include a sticky, yellow or greenish-yellow eye discharge in the corner of the eye.

    In some cases, this discharge can be severe enough to cause the eyelids to be stuck together when you wake up. One or both eyes can be affected. Bacterial conjunctivitis is contagious, generally by direct contact with infected hands or items that own touched the eye.

  1. Allergic conjunctivitis symptoms include watery, burning, itchy eyes and are often accompanied by stuffiness and a runny nose, and sensitivity to light. Allergic conjunctivitis affects both eyes, but this type of pink eye is not contagious.

Conjunctivitis — also known as "pink eye," is inflammation of the thin, clear covering of the white of the eye and the inside of the eyelids (conjunctiva).

Conjunctivitis can own several causes (see below), but numerous eye doctors use the term "pink eye" to refer only to viral conjunctivitis, a highly contagious infection caused by a variety of viruses.

"Pink eye" may sound scary to hear, but this common eye problem typically is easily treated.

Moreover, with a few simple precautions, pink eye often can be avoided. One type of conjunctivitis, though, can cause serious vision issues if left untreated. See your eye doctor if you are concerned about your pink eye.

NEED AN EYE EXAM? Discover an eye doctor near you and schedule an appointment.

Anyone can get pink eye, but office workers, store employees, preschoolers, schoolchildren, college students, teachers and kid care workers are particularly at risk for the contagious types of pink eye because they work closely with others.

Here’s what you need to know about pink eye:

10 Conjunctivitis Prevention Tips

Now that you know the basics about viral pink eye and other forms of conjunctivitis, what can you do to protect yourself and your kids from getting pink eye?

Resources We Love

Favorite Orgs for Essential Pink Eye Info

American Academy of Ophthalmology (AAO)

Learn every the fundamentals about pink eye from the professional medical association of ophthalmologists (medical doctors who specialize in eye care).

The site displays some eye-opening photographic and video examples of conjunctivitis, as well as quick home remedies.

American Optometric Association (AOA)

The AOA looks at the essential aspects of pink eye, including causes, diagnosis, and treatment. Because excellent hygiene is one of the best ways to control conjunctivitis, the association instructs readers on best practices to prevent this inflammation.

The College of Optometrists

The College of Optometrists highlights guidelines on the diagnosis and management on a type of conjunctivitis that occurs in newborns within the first month of life.

The cause is a sexually transmitted disease in a parent. The site discusses diagnosis, prevention, and treatment.

Centers for Disease Control and Prevention (CDC)

The CDC gives in-depth information about causes, treatments, and the diverse types of this ailment, including viral, bacterial, and allergic conjunctivitis. The site features a fact sheet, a helpful infographic, and a podcast by a pediatrician who specializes in the condition.


A digital extension from the American Academy of Pediatrics, this group answers parents’ health questions regarding children of every ages, including inquiries concerning conjunctivitis.

For example, one of the AAP doctors replies to a query asking “Do I need to hold my son home if he has pink eye?”

National Eye Institute

Part of the National Institutes of Health, this organization lays out the facts about pink eye, telling you how to recognize it, take care of it, and avoid getting it altogether. You can also search for news, events, and latest research on the topic.

Favorite Orgs for Related Pink Eye Info

American Board of Internal Medicine Foundation (ABIMF)

ABIMF supports the Choosing Wisely initiative to promote conversations between clinicians and patients.

The site addresses several eye-heath subjects, such as conjunctivitis. The website explains when antibiotics are and aren’t needed for pink eye.

Measles and Rubella Initiative

Because measles has been making a comeback recently among unvaccinated children and pink eye can be a symptom of measles, it’s helpful to know other symptoms of measles and how to identify the potentially life-threatening disease. The Measles and Rubella Initiative describes the serious health consequences from measles and why vaccination is so important.

Favorite Blogs Related to Pink Eye

Nationwide Children’s Hospital 700 Children’s Blog

This blog gives parents access to the most current pediatric news and research.

A portion of the blog gives parents a guide to pink eye with advice on symptoms and home care.

«Pinkeye» redirects here. For other uses, see Pinkeye (disambiguation).

Conjunctivitis, also known as pink eye, is inflammation of the outermost layer of the white part of the eye and the inner surface of the eyelid.[4] It makes the eye appear pink or reddish.[1] Pain, burning, scratchiness, or itchiness may occur.[1] The affected eye may own increased tears or be «stuck shut» in the morning.[1] Swelling of the white part of the eye may also occur.[1] Itching is more common in cases due to allergies.[3] Conjunctivitis can affect one or both eyes.[1]

The most common infectious causes are viral followed by bacterial.[3] The viral infection may happen along with other symptoms of a common cold.[1] Both viral and bacterial cases are easily spread between people.[1] Allergies to pollen or animal hair are also a common cause.[3] Diagnosis is often based on signs and symptoms.[1] Occasionally, a sample of the discharge is sent for culture.[1]

Prevention is partly by handwashing.[1] Treatment depends on the underlying cause.[1] In the majority of viral cases, there is no specific treatment.[3] Most cases due to a bacterial infection also resolve without treatment; however, antibiotics can shorten the illness.[1][3] People who wear contact lenses and those whose infection is caused by gonorrhea or chlamydia should be treated.[3] Allergic cases can be treated with antihistamines or mast cell inhibitor drops.[3]

About 3 to 6 million people get conjunctivitis each year in the United States.[1][3] In adults, viral causes are more common, while in children, bacterial causes are more common.[3] Typically, people get better in one or two weeks.[1][3] If visual loss, significant pain, sensitivity to light, signs of herpes, or if symptoms do not improve after a week, further diagnosis and treatment may be required.[3] Conjunctivitis in a newborn, known as neonatal conjunctivitis, may also require specific treatment.[1]

What Causes Conjunctivitis?

The primary types of conjunctivitis, based on cause, are:

  1. Viral conjunctivitis. Caused by a virus, love the common freezing.

    This type of pink eye is extremely contagious, but generally will clear up on its own within several days without medical treatment.

  1. Bacterial conjunctivitis. Caused by bacteria, this type of conjunctivitis can cause serious damage to the eye if left untreated.
  1. Allergic conjunctivitis. Caused by eye irritants such as pollen, dust and animal dander among susceptible individuals. Allergic conjunctivitis may be seasonal (pollen) or flare up year-round (dust; pet dander).