Conjunctivitisis an inflammation of the conjunctiva caused by a virus (viral conjunctivitis), bacteria (bacterial conjunctivitis), an allergy (allergic conjunctivitis), or even a toxic cause.
The term keratitis defines an inflammation of the cornea.
In practice, the two inflammations are very often associated: we speak of keratoconjunctivitis.
It is important to dissociate the two because some keratitis can cause serious after-effects.
To simplify, we will speak of conjunctivitis and keratoconjunctivitis under the generic term of "conjunctivitis".
(See the article on keratitis)
Conjunctivitis can be very contagious.
The symptoms are:
– redness,
– irritation of the eye, itching,
– burning or scratching sensations,
– or purulent-looking discharge,
The patient often complains of pain, eye fatigue, and a feeling of sand in the eyes.
The clinical pictures differ depending on the cause of this conjunctivitis:
Viral conjunctivitis has the particularity of simultaneously affecting several tissues (nose, lungs, intestines, joints, meninges, etc.) and of course the eye and more particularly the conjunctiva.
Most viral infections produce benign conjunctivitis. They first affect one eye, then spread to the other in the following days.
Some are more irritating, this irritation is the main reason for discomfort and consultation. They can be visually disabling. The most common forms of viral conjunctivitis are:
– epidemic keratoconjunctivitis, irritating, very contagious but generally very benign,
– pharyngoconjunctival fever. The latter is characterized by fever, sore throat and conjunctivitis. It can be unilateral or bilateral. The condition is contagious for 1 month. Corneal involvement is rare. Visual disturbance and discomfort vary in severity, persisting for a few days to 3 weeks.
Both conditions are caused by adenoviruses. Their key clinical signs are common: conjunctival congestion, tearing, discharge, swollen eyelids.
Lymph nodes are palpable nearby.
Both conditions are highly contagious.
Bacterial conjunctivitis:
Affected patients have inflammation that is always visible at least under the eyelids. The infection often starts in one eye and then spreads to the other. A purulent discharge is usually observed. The eyelids are swollen and stuck together upon waking. The swelling subsides when standing. Reappearance the next day despite treatment is normal and is due to the lying down position.
There may be a sensation of sand or a foreign body in the eye, but there is usually no intense pain.
Visual function is not impaired, at most there may be a "veil" in front of the eyes, due to the edema.
The bacteria most frequently observed in common conjunctivitis are Staphylococcus aureus, Haemophilus influenzae, Streptococcus pneumoniae and Pseudomonas aeruginosa.
Atypical germ conjunctivitis:
Two atypical germs occasionally affect the eyes, chlamydia and mycoplasma.
Chlamydia often affects young adults. The ocular involvement affects the conjunctiva but can also affect the iris and cause intense pain. This condition, which can be due to sexual contamination, is found in a complex picture, the Fiessenger Leroy Reiter syndrome: it is more or less constantly associated with urethritis (inflammation of the lower urinary tract) and joint pain. The treatment is antibiotic.
Mycoplasma conditions often also have a sexual origin. The picture is essentially the same, but less acute. The treatment is also antibiotic.
Allergic conjunctivitis:
Patients affected by this conjunctivitis are often known allergy sufferers or people with allergic family members. This conjunctivitis is seasonal, corresponding to a specific allergen (pollen, mites). The onset is sudden, both eyes are affected simultaneously. Conjunctival inflammation varies greatly from one subject to another. We observe modest to very abundant, liquid tearing, often associated with abundant nasal discharge and sneezing and sometimes intense itching. Sometimes the symptoms are limited to simple symmetrical irritation with a sensation of sand in the eyes.
The treatment most often consists of putting in antiallergic eye drops. Desensitization is possible with good results when the allergic phenomena last several months during the year (grasses), and the patient is not affected by a multitude of allergens.
Toxic conjunctivitis:
They follow exposure to toxic contact. The mechanism is irritative.
The causes are:
- exposure to irritating fumes: smoking, cannabis use ++, the simplest treatment is to stop exposure,
- projection of chemical products: in this case it is essential to rinse abundantly with running water for as long as possible and to urgently consult an ophthalmologist: the risk is chemical burn of the cornea responsible for irregularity of the cornea, scars and significant discomfort with loss of transparency.
