One of the most common eye diseases is conjunctivitis or pink eye. Often the treatment of conjunctivitis uses antibiotics. Is giving antibiotics in acute conjunctivitis treatment necessary?

Should Acute Conjunctivitis Treatment Require Topical Antibiotics?
Illustration Treating Acute Conjunctivitis use Eye Drop.

Conjunctiva and Conjunctivitis


The conjunctiva is a thin transparent mucous membrane that lines the anterior part of the eyeball and inner palpebral. Conjunctivitis is an inflammatory disease of the conjunctiva. Patients with conjunctivitis usually complain of red eyes, conjunctival edema, and excess secretions. These symptoms result from vascular dilation, cellular infiltration, and exudation.

Types of conjunctivitis

Based on the cause, conjunctivitis is divided into infectious and non-infectious conjunctivitis. The most common causes of infectious conjunctivitis are viruses and bacteria, while the non-infectious group causes are allergies, toxic reactions, and other secondary inflammation.

Based on symptom onset, conjunctivitis is classified into acute and chronic conjunctivitis. In acute conjunctivitis, symptoms last up to four weeks, whereas in chronic conjunctivitis, symptoms last for more than four weeks.

Mostly, acute conjunctivitis is caused by viral infections and allergies. Viral conjunctivitis is most common in society and has a self-limiting character.

Reasons for Administration of Antibiotics in Treating Acute Conjunctivitis

Viruses (60-80%) and allergens are the main etiologies of acute conjunctivitis in adults. Acute conjunctivitis is generally self-limited and usually resolves within 7-14 days without antibiotics, so supportive therapy is recommended. Antibiotic eye drops are preferred in patients with severe acute bacterial conjunctivitis.

Although the recommended treatment is supportive therapy, many patients still receive topical antibiotics as empirical treatment. This is caused by:
  • the perception that antibiotics are "harmless";
  • difficulty in differentiating viral and bacterial conjunctivitis;
  • minimize the possibility of complications due to bacterial infection.

Complications of Topical Antibiotics

Inappropriate use of antibiotics can have several effects, including increasing unnecessary spending on antibiotics (not cost-effective), increasing the risk of antibiotic resistance, and disturbing the normal flora on the surface of the eye. A total of four doses of antibiotic eye drops can make a significant difference in eye flora and increase the risk of developing multidrug-resistance.

20% of the topical antibiotics used are available in combination with corticosteroids. Corticosteroids are known to increase adenovirus shedding (60-95% of viral conjunctivitis etiology). On the other hand, it can also prolong the duration of viral infection and the risk of reactivation of latent ocular herpes infection.

Another serious complication is an allergic reaction to topical antibiotics. The allergic reaction symptoms that arise within 30 minutes to 24-72 hours after eye drops include:
  • epiphora, 
  • eyelid edema, 
  • chemosis, 
  • conjunctival injection, 
  • hyperemia, 
  • and rhinitis.

How to Differentiate Viral and Bacterial Conjunctivitis

The difficulty in differentiating between acute bacterial and viral conjunctivitis is one reason for antibiotic use. In general, conjunctivitis is characterized by erythema and conjunctival injection. In a minority of patients, there is eyelid involvement and lymphadenopathy. Other acute conjunctivitis symptoms are mild pruritus, foreign body sensation, mild photophobia, without decreased visual acuity.

a. Viral Conjunctivitis
Viral conjunctivitis is usually unilateral, then becomes bilateral within a few days, with palpebral edema and watery (serous) eye secretions. Photophobia and itching of the eyes are rare in viral conjunctivitis. Photophobia is more common in bacterial conjunctivitis, whereas itching is more common in allergic conjunctivitis. Antigen detection on conjunctival swabs to determine the cause of viral conjunctivitis has a sensitivity of 89% and a specificity of 94%.

Viral conjunctivitis can also manifest as acute hemorrhagic conjunctivitis and follicular conjunctivitis. Acute hemorrhagic conjunctivitis is characterized by subconjunctival hemorrhage that begins with petechiae. Follicular conjunctivitis is characterized by the formation of small follicles on the palpebral conjunctiva.

b. Bacterial conjunctivitis
The presence of hyperpurulent  (Gonococcus) or mucopurulent (non-gonococcal) discharge indicates bacterial conjunctivitis. Making a definite diagnosis is obtained by culturing an infected conjunctival swab sample. This method can give a false-positive result due to normal flora's presence on the conjunctiva's surface.

Purulent discharge in bacterial conjunctivitis does not always appear in all patients. It makes to differentiate viral and bacterial conjunctivitis difficulty. Bhattacharyya et al. conducted a study involving 110 respondents with bacterial conjunctivitis. They found that purulent and mucopurulent secretions were only in 58.18% and 41.8% of respondents.

Can Topical Antibiotics Be Delayed?

Yes, it can be delayed because acute conjunctivitis is self-limiting. The American Academy of Ophthalmology (AAO) recommends delaying antibiotic administration in treating viral conjunctivitis and unknown etiology cases. The reasons are:
  • topical antibiotics are toxic to the eye surface,
  • can create resistance when used irrationally,
  • and increase medical expenses.
Several studies show that topical antibiotics administration in bacterial conjunctivitis has little effect on symptom remission.

The recommended management strategy for acute conjunctivitis is to provide supportive therapy and delay antibiotic administration. Supportive therapy includes eye cleaning with sterile water and a cotton ball, warm compresses, and temporary use of artificial tears to reduce discomfort. Consider giving topical antibiotics if there is no improvement in symptoms with adequate supportive management for two days.

A clinical trial comparing the prompt and delayed administration of antibiotics in 307 adult respondents and children with acute conjunctivitis showed that the two groups had similar duration and severity of symptoms. This study shows that antibiotics can be reduced, although education to patients about supportive treatment, hygiene, and healthy living habits should be carried out.

Antibiotics can be used in patients with severe acute conjunctivitis, which is characterized by:
  • excessive lacrimation, 
  • redness, 
  • and edema of the conjunctiva and fornix.

Acute conjunctivitis is often caused by a virus. The nature of acute conjunctivitis is self-limited, but many patients are still being treated with antibiotics.

The existing studies showed no significant differences in disease duration and severity between patients who received topical antibiotics and those who did not. In addition, irrational use of antibiotics can lead to increased medical costs, risk of bacterial resistance, changes in the normal flora of the eye, and allergic reactions.

Antibiotics may be considered in severe acute bacterial conjunctivitis cases or if symptoms do not improve after two days of supportive therapy.