Conjunctivitis is an "inflammation of the thin layer of tissue, called precisely conjunctiva, which covers the inner surface of the eyelids and the anterior surface of the eyeball. The conjunctiva is lubricated by the secretion emitted by the lacrimal glands and has the function of defending the eye from microorganisms and protecting it from foreign substances and objects.

Conjunctivitis is one of the most common eye diseases and can manifest itself in an acute or chronic form. It can affect only one eye and then extend to both. It can in fact be caused by a bacterial or viral infection or by other microorganisms or parasites (infectious conjunctivitis).

It can also result from an allergic reaction to elements such as pollen, dust mites, animal hair, drugs (allergic conjunctivitis) or from contact with chemicals such as soaps, cosmetics, acids, alkalis, and also from physical agents of various kinds, including which excessive exposure to sunlight and other radiation (conjunctivitis from chemical and physical agents).



The disorders (symptoms) caused by conjunctivitis vary according to the causes that led to the inflammation. They include:

  • redness of the eyes (hyperemia)
  • increased tear secretion
  • foreign body sensation in the eye (like "sand")
  • swelling of the eyelids
  • sensitivity to light (photophobia)
  • purulent discharge (in particular, in infectious conjunctivitis, in the morning the eye has a sticky secretion on the eyelashes, usually yellowish in color)
  • itch
  • eye pain / discomfort(if there is corneal involvement)
  • blurred or blurred vision

In allergic conjunctivitis the disorders (symptoms) also depend on the substance (allergen) that caused the allergy. If it is allergens present only in a particular period of the year (for example pollen) the inflammation will be seasonal.



Conjunctivitis is inflammation of the conjunctiva, a thin membrane that covers the inner surface of the eyelids and the anterior surface of the eyeball.

The most common causes are:

  • infection (infectious conjunctivitis)
  • allergic reaction (allergic conjunctivitis)
  • contact with irritating chemicals or physical agents of various kinds

Infectious conjunctivitis it can be caused by bacteria, viruses (often adenoviruses, which can also cause a sore throat and high fever), or sexually transmitted infections (STIs) such as chlamydia or gonorrhea.

The main types of allergic conjunctivitis I am:

  • seasonal allergic conjunctivitis (the characteristic disturbances occur at certain times of the year)
  • perennial allergic conjunctivitis (the characteristic disturbances occur throughout the year)
  • contact dermatoconjunctivitis
  • gigantopapillary conjunctivitis

Seasonal allergic conjunctivitis and perennial allergic conjunctivitis they can be caused by an allergic reaction to elements such as pollen, dust mites, animal hair, drugs. These types of conjunctivitis most commonly affect people who already suffer from other forms of allergy, including food allergies, and are often associated with rhinitis (allergic rhino-conjunctivitis).

Contact dermatoconjunctivitis (or blepharoconjunctivitis) is an "inflammation of the conjunctiva and the skin (skin) of the eyelids caused by an allergic reaction to products or substances such as eye drops and cosmetics or powders.

Gigantopapillary conjunctivitis it is characterized by an "inflammation of the inner surface of the eyelids (eyelid or tarsal conjunctiva) often caused by the use of contact lenses, especially soft ones or by the presence of foreign bodies, ocular prostheses, conjunctival or corneal sutures.

Conjunctivitis can also be of an irritative type, caused by chemical or physical agents of various kinds. In this case, inflammation can occur due to contact of the conjunctiva with irritating agents such as chemicals (soaps, chlorine present in swimming pool water), due to the penetration of foreign bodies into the eye, due to the presence of smoke or due to excessive exposure to sunlight or other radiation (actinic conjunctivitis). Exposure to strong air currents (for example, traveling by motorbike or boat without adequate protection) can cause irritation of the conjunctiva.

Some of these forms of conjunctivitis can be caused by exposure to dust or other substances generated by the work environment.



The medical examination and the analysis of the disorders reported by the person who is affected are essential to ascertain (diagnose) the presence of conjunctivitis. Especially in the case of conjunctivitis in newborn babies (neonatal) or, in any case, in young children, who are more exposed to the risk of infections, it is important to ascertain it (diagnose it) as soon as possible to immediately start adequate therapy.

The ophthalmologist, through the use of optical instruments, examines the eye to assess the severity of the condition, check for inflammation and the possible presence of lesions or rashes on the edges of the eyelids or on other parts of the eye (for cornea for example).

In particular, in the case of infectious conjunctivitis, to identify the type of infection and establish the most effective therapy to eradicate it, the specialist may ask to perform the so-called "conjunctival swab", a painless examination which consists in taking a small amount (sample) of conjunctival secretion through the use of a stick similar to a cotton swab; the sample will then be analyzed in the laboratory to verify the cause of the infection.

The so-called differential diagnosis, that is to say, the identification of the exact cause of the disorder among the many possible ones, is very important for the purposes of therapy because it allows to distinguish viral and bacterial (infectious) conjunctivitis from other forms (allergic or contact) as well as from possible diseases of the eye that can present similar disorders such as, for example, keratitis, keratoconjunctivitis, uveitis.



The treatment (therapy) of conjunctivitis varies according to the type of inflammation and the causes that caused it.

Infectious conjunctivitis (bacterial and viral)

Most cases of infectious conjunctivitis do not need medical treatment and resolve in a week or two, but if the discomfort persists longer, it is essential to identify the cause and prescribe an appropriate "therapy. Treatment can be started directly at home following simple directions:

  • gently cleanse your eyes with a cotton swab
  • do not use contact lenses until the signs of infection have completely disappeared and absolutely do not reuse the same lenses after healing, as they could cause infection again
  • apply lubricating eye drops (artificial tears)
  • always wash your hands after touching your eyes

However, if the infection lasts for several weeks, it is strongly advised to consult the specialist who can prescribe a targeted therapy.

If it is bacterial conjunctivitis, which is the most common form, antibiotics may be prescribed in the form of eye drops or eye cream. For repeated (recurrent) infections, the ophthalmologist may consider prescribing a tampon conjunctival with antibiogram, a test that identifies the germs responsible for the infection and indicates the most suitable antibiotics to defeat them.

In cases of viral conjunctivitis, mainly caused by adenovirus and herpesvirus, the doctor may prescribe antiviral drugs.

Allergic conjunctivitis

If the conjunctivitis is allergic in nature, the following can be prescribed by the doctor:

  • antihistamines
  • mast cell stabilizers
  • corticosteroids (however, to be used with caution)
  • decongestants
  • anti-inflammatory

However, it is advisable to avoid:

  • use contact lenses
  • rub your eyes with your hands so as not to exacerbate the irritation
  • expose yourself to the allergen which causes allergy

Gigantopapillary conjunctivitis

In the cases of gigantopapillary conjunctivitis, generally caused by the use of contact lenses, the disorders (symptoms) often resolve themselves by avoiding their use: it is however recommended to carry out an eye examination to eventually change the type of contact lenses to wear when the conjunctivitis is resolved. If the reaction is due to the presence of ocular prostheses, conjunctival or corneal sutures, it is necessary to contact the specialist immediately.

If conjunctivitis is the consequence of a reaction caused by contact with irritants contained for example in cosmetics, soaps, perfumes, detergents or caused by physical agents such as fumes or excessive exposure to sunlight or other radiation, it is necessary to avoid the cause identified as responsible for conjunctival inflammation.



Conjunctivitis of the infectious type

To prevent infectious conjunctivitis it is useful to follow simple precautions:

  • wash your hands often with soap and water (Video)
  • avoid touching or rubbing the healthy eye after touching the infected eye
  • change the pillow case and towels frequently
  • avoid close contact with other people
  • Throw away any used make-up cosmetics in the trash in the early stages of the infection to prevent it from happening again. Above all, carefully avoid using the cosmetics used for an irritated eye on both eyes

Seasonal allergic conjunctivitis

In cases of seasonal allergic conjunctivitis it is good to follow some practical precautions:

  • keep the windows closed to prevent the entry of pollen
  • travel with the windows closed by car
  • avoid the fields where the grass is cut
  • wash and brush your hair often as they could retain the pollen present in the air
  • avoid practicing outdoor sports

If you are allergic to dust mites you can take precautions such as:

  • ventilate the premises often
  • maintain a temperature in the house that does not exceed 20 ° C
  • eliminate or minimize all possible dust receptacles such as rugs, carpets, upholstered sofas, dried flowers
  • use closed libraries
  • avoid wallpaper
  • wash bedding often at a temperature not lower than 50 ° C
  • clean the house often using a vacuum cleaner (preferably those with HEPA or water filters)

Conjunctivitis by chemical or physical agents

In the case of conjunctivitis caused by irritating chemical or physical agents:

  • wear sunglasses or protective goggles for work: the latter must always be used also according to the working context. Do not forget that the conjunctiva can be the mucous membrane of entry of infectious agents dangerous not only for the conjunctiva itself, but also for other organs
  • avoid contact with irritantsor to stay for a long time in environments where these substances are stored without adequate ventilation (for example warehouses, cellars)
  • avoid smoky or dusty environments


Conjunctivitis, if treated correctly, is usually a condition that resolves completely and fairly quickly. In some cases, however, complications may arise, some of them even serious, such as:

  • meningitis (acute or chronic inflammation of the meninges, of viral or bacterial origin)
  • cellulite (limited inflammation of the subcutaneous adipose tissue, produced by direct infection or by propagation)
  • septicemia (pathology due to the persistent presence in the blood of bacteria such as streptococci, staphylococci, pneumococci, meningococci, etc.) or, less frequently of fungi, which manifests itself with imposing and rather characteristic symptoms (high fever, variously compromised general state, sometimes haemorrhagic manifestations )
  • otitis media (inflammation or infection of the middle ear, which occurs in the area between the tympanic membrane and the inner ear; affects about 25% of children who have had infectious conjunctivitis caused by the bacterium haemophilus influeanzae)
  • conjunctival hemorrhage
  • formation of small vesicles along the edge of the eyelids (typical lesions induced by herpes viruses)
  • blurred vision
  • keratitis (inflammation of the cornea)

In infants, infectious conjunctivitis can cause a "serious eye infection which, if not treated properly, could cause permanent vision damage, while chlamydial conjunctivitis can cause otitis media or pneumonia.

Living with

Living with

The useful recommendations for the prevention of the various forms of conjunctivitis are also valid for those who often suffer from this inflammation, especially if they are allergic individuals who are, therefore, subject to frequent episodes.

Following the right hygiene rules, avoiding the causes that can trigger both an allergic and an irritant reaction, leading a healthy lifestyle are always valid indications.

In people who often suffer from conjunctivitis it is advisable to increase the frequency of eye examinations throughout the year.



NHS Choices. Conjunctivitis (English)

International Agency for the Prevention of Blindness-IAPB Italia Onlus. Conjunctivitis

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