Eyes: Conjunctivitis, Orbital & Periorbital Cellulitis Flashcards
What is conjunctivitis?
Inflammation of the conjunctiva (thin membrane that covers the sclera and lines the inner surface of the eye).
Conjunctivitis may be bacterial, viral or allergic.
What are the 4 most common bacterial causative organisms?
1) Staph. aureus
2) Strep. pneumoniae
3) H. influenzae
4) Moraxella catarrhalis
What are the 4 most common viral causes of conjunctivitis?
1) Adenovirus (most common)
2) HSV
3) VZV
4) Enterovirus
What is the most common virus causing infective conjuctivitis?
Adenovirus
Features of bacterial vs viral conjunctivitis?
Bacterial:
- purulent discharge
- eyes may be ‘stuck together’ in morning
Viral:
- serous discharge
- recent URTI e.g. dry cough, sore throat
- preauricular lymph nodes
Are bacterial & viral conjunctivitis contagious?
yes - both are
Onset of symptoms in conjunctivitis?
Acute onset of symptoms, typically unilateral but may become bilateral within 24-48 hours.
What may be present in history in conjunctivitis?
- Recent exposure to an infected individual, swimming in contaminated water, or contact lens use.
- Presence of comorbidities e.g. URTI or atopy.
Clinical symptoms of conjunctivitis?
-Red, bloodshot eye
- Ocular discomfort, itching, burning sensation.
- Foreign body sensation or grittiness in the affected eye(s).
- Photophobia may be present in cases of viral conjunctivitis.
- Discharge: watery in viral, purulent in bacterial
What symptoms does conjunctivitis NOT cause?
Does NOT cause pain, photophobia or reduced visual acuity.
Discharge covering the eye may cause blurry vision, but this should return to normal when the discharge is cleared.
Potential clinical signs in conjunctivitis?
- Conjunctival injection and chemosis.
- Eyelid swelling and erythema.
- Palpable preauricular lymphadenopathy (viral)
- Subconjunctival haemorrhage may be present in cases of adenoviral conjunctivitis
what are some causes of an acute PAINFUL red eye? (7)
1) Acute angle-closure glaucoma
2) Anterior uveitis
3) Scleritis
4) Corneal abrasions or ulceration
5) Keratitis
6) Foreign body
7) Traumatic or chemical injury
Note - Conditions that require emergency same-day referral to ophthalmology tend to cause pain or reduced visual acuity.
what are some causes of an acute PAINLESS red eye? (3)
1) Conjunctivitis
2) Episcleritis
3) Subconjunctival haemorrhage
Typical management of infective conjunctivitis?
Normally a self-limiting condition that usually settles without treatment within 1-2 weeks.
Hygiene measures to reduce spreading e.g. avoiding towel sharing and close contact.
Clean eyes with cooled boiled water and cotton wool can help clear the discharge.
What are 2 pharmacological options for bacterial conjunctivitis if necessary?
1) Chloramphenicol (eye drops)
2) Fusidic acid (eye drops)
What medical management is indicated for conjunctivitis in pregnant women?
Fusidic acid
Indications for chloramphenicol? (2)
1) Superficial bacterial eye infections
2) Bacterial infection in otitis externa
Key contraindications of chloramphenicol?
Acute porphyrias
Pregnacy & breastfeeding
Is chloramphenicol safe in pregnancy & breast feeding?
No
What is risk of using Chloramphenicol in pregnancy?
‘Grey baby’ syndrome
What age children with conjunctivitis need urgent ophthalmology assessment?
Neonates <1 month old
Why do neonates with conjunctivitis need urgent ophthalmology assessment?
Neonatal conjunctivitis may be caused by gonococcal infection, which can cause serious complications (e.g., permanent vision loss).
Is school exclusion necessary in infective conjunctivitis?
No