Prudence Urged When Prescribing Antibiotics for Acute Conjunctivitis

Misuse can lead to serious visual and financial ramifications. Cheryl Guttman Krader reports from Milan

Antibiotic misuse for acute conjunctivitis is a common and serious issue, as it contributes to the growing global problem of antimicrobial resistance, said Mina Abdelmseih MD, MS, FEBO.

“I want to emphasise this problem because we are seeing an increasing number of challenging cases of ocular infections caused by methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant S aureus. Sadly, some of these patients ended up blind because we could not use anything to treat them,” Dr Abdelmseih told EuroTimes.

“New scientific guidelines should be developed to help doctors and patients avoid misuse of antibiotics. In addition to new generations of antibiotics, proper use of antibiotics could be a lifesaving factor, and it will also help to decrease billions in unnecessary costs.”

CONSIDER THE DIAGNOSIS Acute conjunctivitis is a common condition with multiple aetiologies, and most cases are not related to bacterial infection, said Dr Abdelmseih.

“Only 135 in 10,000 cases of acute conjunctivitis are bacterial disease. About 80% of cases of acute conjunctivitis are viral, and allergy is also a more common cause of acute conjunctivitis than bacterial infection,” he said.

Other entities to consider in the differential diagnosis include blepharitis, dry eye syndrome, subconjunctival haemorrhage, acute glaucoma, episcleritis, scleritis, and now, SARS-CoV-2 infection.

UNNECESSARY USE Even if the conjunctivitis is bacterial, antibiotic treatment is usually unnecessary because most cases of bacterial conjunctivitis are mild, self-limiting, and do not lead to serious complications. Although antibiotic treatment may shorten symptom duration and hasten microbiological eradication, results from placebo-controlled studies show the benefit is modest. A review of the available literature revealed antibiotic treatment for acute bacterial conjunctivitis had an advantage for improving clinical outcomes only between days two and five. Within the placebo-treated groups, about 65% of patients achieved complete resolution of bacterial conjunctivitis within five days and the percentage rose to 90% by two weeks.

Misuse of antibiotics chart.

Types of conjunctivitis :

A-Viral Conjunctivitis:

•viruses occur in 80% of all patients of acute conjunctivitis. Most cases are wrongly diagnosed as bacterial conjunctivitis.

B-Allergic conjunctivitis

•There is no role of antibiotics in allergic conjunctivitis.

c-Bacterial Conjunctivitis:

•the occurrence of bacterial conjunctivitis was approximated to be 135 in 10,000.

D-Chemical burns

E-Ophthalmia Neonatorum F-Zika Virus

G-SARS-CoV-2 (Coronavirus):

•Conjunctivitis is reported, and it is associated with fever and respiratory symptoms such as sneezing, cough and shortness of breath besides a history of international travel.

Types of conjunctivitis and differential diagnosis.

Differential diagnosis :

´A-blepharitis ´B-subconjunctival

hemorrhage

´C-dry eye syndrome ´D-acute glaucoma ´E-keratitis ´F-iritis ´G-scleritis ´H-episcleritis

“When antibiotics are used to treat bacterial conjunctivitis, clinicians should be aware that misuse with improper dosing, repeated use, and extended use also promote antimicrobial resistance.”

“Misuse of antibiotics has also led to increased ocular surface colonisation with coagulasenegative Staphylococcus...and there are increasing reports of vancomycin-resistant S aureus isolating from ocular infections.”

“There is not a big difference in outcomes between the placebo and active treatment groups. Furthermore, no serious side effects have been reported in the active or placebo groups, indicating that sight-threatening complications are infrequent in cases of acute bacterial conjunctivitis. So, there is no need to use antibiotics for most patients,” Dr Abdelmseih told EuroTimes.

When antibiotics are used to treat bacterial conjunctivitis, clinicians should be aware that misuse with improper dosing, repeated use, and extended use also promote antimicrobial resistance.

DOCUMENTING RESISTANCE Reports in the published literature document the existence of antimicrobial resistance to commonly used topical antibiotics among clinical isolates from patients with bacterial conjunctivitis. Researchers report resistance to gentamicin, tobramycin, and polymyxin B among Streptococcus pneumoniae strains isolated from children with acute conjunctivitis as well as high levels of resistance to azithromycin among clinical isolates of Haemophilus influenzae, S pneumonmiae, S aureus, and Staphylococcus epidermidis. In addition, an increase in bacterial conjunctivitis caused by MRSA has been noted, Dr Abdelmseih said.

“Misuse of antibiotics has also led to increased ocular surface colonisation with coagulase-negative Staphylococcus. These organisms express methicillin and multidrug-resistant isolates, and there are increasing reports of vancomycin-resistant S aureus isolating from ocular infections,” he said.

Mina Abdelmseih MD, MS Ophthalmology, FEBO works in the department of ophthalmology, Augen AMVZ, Germany. dr.mina.abdelmseih@gmail.com