Is pink eye the same as conjunctivitis?

Pink Eye and Conjunctivitis: Understanding the Relationship

Yes, pink eye is the same as conjunctivitis. "Pink eye" is the common term used to describe conjunctivitis, which is inflammation of the conjunctiva - the thin, transparent membrane covering the white part of the eye and the inner surface of the eyelids. 1, 2

Types of Conjunctivitis

Conjunctivitis (pink eye) can be classified into several categories based on etiology:

Infectious Causes

1. Viral Conjunctivitis

   • Most common overall cause of infectious conjunctivitis 3
   • Typically presents with:
     • Abrupt onset
     • Unilateral or bilateral (often sequentially bilateral)
     • Watery discharge
     • Follicular reaction of inferior tarsal conjunctiva
     • Bulbar conjunctival injection (redness)
     • Self-limited, resolving within 5-14 days 1
   • Adenovirus is the most common viral cause

2. Bacterial Conjunctivitis

   • Second most common cause of infectious conjunctivitis 3
   • Key features:
     • Mucopurulent or purulent discharge
     • Mattering and adherence of eyelids upon waking
     • Lack of itching
     • Papillary reaction in tarsal conjunctiva
     • Most cases resolve in 1-2 weeks 1, 3

3. Special Forms of Infectious Conjunctivitis

   • Gonococcal and chlamydial conjunctivitis require systemic treatment in addition to topical therapy 1, 3
   • Herpes simplex and varicella zoster can cause conjunctivitis with distinctive vesicular rashes 1

Non-Infectious Causes

1. Allergic Conjunctivitis

   • Affects up to 40% of the population 3
   • Characterized by:
     • Itching (most consistent symptom)
     • Conjunctival hyperemia
     • Edema
     • Papillary reaction 2
   • Subtypes include seasonal/perennial allergic conjunctivitis, vernal keratoconjunctivitis, and atopic keratoconjunctivitis 1, 2

2. Other Non-Infectious Causes

   • Medication-induced/preservative-induced keratoconjunctivitis
   • Contact lens-related giant papillary conjunctivitis
   • Immune-mediated conditions (e.g., ocular mucous membrane pemphigoid)
   • Neoplastic processes 1, 2

Clinical Differentiation

The clinical presentation helps distinguish between different types of conjunctivitis:

• Papillary reaction (small bumps on the conjunctiva): More common in bacterial and allergic conjunctivitis 2
• Follicular reaction (small lymphoid follicles): More common in viral and toxic conjunctivitis 2
• Discharge type:
  • Watery: Typically viral or allergic
  • Mucopurulent/purulent: Typically bacterial 1, 2
• Itching: Strong indicator of allergic etiology 3
• Unilateral vs. bilateral: Bacterial often starts unilateral; viral often becomes bilateral; allergic typically bilateral 1

Treatment Approaches

Treatment varies based on the type of conjunctivitis:

• Viral conjunctivitis: Mostly supportive care as it's self-limiting 3
• Bacterial conjunctivitis:
  • Many uncomplicated cases are self-limiting
  • Topical antibiotics can decrease duration and allow earlier return to work/school 3
• Allergic conjunctivitis: Topical antihistamines and mast cell stabilizers 3

Important Cautions

• Red eye can occasionally be a sign of more serious conditions requiring urgent ophthalmologic evaluation:
  • Acute glaucoma (red eye with severe pain and vomiting)
  • Keratitis (corneal involvement)
  • Uveitis 4
• Avoid prescribing topical corticosteroids without ophthalmologic consultation as they can worsen certain infections, particularly herpes simplex virus 5, 4

When to Refer to an Ophthalmologist

Refer to an ophthalmologist when:

• No improvement after 10 days of treatment
• Severe pain or visual impairment
• Signs of corneal involvement
• Chronic or recurrent red eye 4

Pink eye (conjunctivitis) is generally a benign condition but proper identification of the specific type is important for appropriate management and to prevent complications.