Bacterial Conjunctivitis (Pink Eye) Clinical Presentation

Updated: Feb 07, 2023
  • Author: Karen K Yeung, OD, FAAO; Chief Editor: Andrew A Dahl, MD, FACS  more...
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The choice of questions to ask when eliciting a clinical history from the patient is influenced by such factors as age, occupation, and social habits. It may occasionally focus on sensitive issues that can be embarrassing to discuss.

Most cases of bacterial conjunctivitis are bilateral, although the time of onset may vary. Most cases of bacterial conjunctivitis occur in otherwise healthy individuals. In these cases, the history should take the following factors into consideration:

  • A brief history to assess possible occupational exposure may be appropriate. A brief history of systemic illness should be obtained to determine whether the patient has recently experienced a viral upper respiratory tract infection, has any major known systemic illnesses (eg, HIV disease or diabetes), or has recently used antibiotics or immunosuppressive medications.
  • History of recent exposure to other cases is extremely helpful, especially to children. An exposure to a case that healed uneventfully would be comforting, whereas exposure to someone with known epidemic keratoconjunctivitis (viral) or severe herpes simplex dermatitis would raise concern.
  • A medication history is important to document what already has been tried and to rule out medicamentosa or other drug-related causes for the condition. Ocular redness and irritation may occur due to any eye drop solution or the preservatives in the solution. Systemic chemotherapeutic agents can cause an irritative conjunctivitis.
  • A history of allergies to medications should be established for avoidance purposes and recorded in the medical record prominently since this is often the only medical encounter with an otherwise healthy individual. Sulfonamides are particularly important because of their relatively high allergy incidence, the common practice of prescribing generic sulfacetamide for routine conjunctivitis, and the implied risk of severe allergic reactions such as Stevens-Johnson syndrome. An allergy history should document not only the medication or antigen but also the type of reaction. Stomach discomfort is of less concern than a diffuse rash, while respiratory distress is a major contraindication to any drug in that class, topical or systemic.
  • Contact lens wear, especially extended-wear contact lens use and/or improper contact lens care, increases the risk of ocular infections, including bacterial conjunctivitis. When the cornea is involved, infections not properly treated can result in corneal scarring and permanent visual impairment.
  • Patients with typical bacterial conjunctivitis do not complain of photophobia. Sensitivity to light is a symptom of intraocular inflammation, as in iritis, or disturbance of the corneal epithelium with lesions that test positive on fluorescein staining, such as those found in viral keratitis, retained corneal foreign body, or a metallic rust ring.
  • Duration of the disease and previous attempts at therapy should be documented. It is usual for symptoms to be present for several days or weeks at the time of presentation. An uncommonly long duration or a frequent recurrence suggests that other factors or conditions may be present. For instance, a molluscum lesion at the lid margin may be shedding virus into the eye. Chlamydial infection or viral keratoconjunctivitis may be present, with subsequent corneal complications. Compliance to antibiotic use can also help determine whether antibiotic resistant bacteria may be involved. A history of resistance to therapy may prompt the practitioner to obtain a culture, which can be effectively obtained with a standard red-cap culturette tube following swabbing of the lower lid margin and inferior cul-de-sac.
  • In the elderly patient, age is a consideration in determining whether the case may be related to defective host resistance. In such cases, it is appropriate to inquire about concomitant or recent increased susceptibility to other types of infections, for example, urinary tract or respiratory tract infections, which may hold clues to the bacterial source. Furthermore, MRSA and MRSE infections are far more prevalent in nursing home residents [22] and in patients who are chronically hospitalized.

Venereal diseases should be considered in patients at a sexually active age. Consider the following:

  • If the conjunctivitis is associated with copious purulence, severe injection, and chemosis, then a discussion of possible exposure to N gonorrhoeae must take place. Bacterial cultures, including Thayer-Martin and chocolate agar, and a Gram stain must be performed, as well as newer nonculture point-of-service immunodiagnostics, if available. Immediate targeted treatment should be initiated.
  • A history of sexual partners must be obtained if the cultures/stain verify this condition so that they also can be treated.
  • The practitioner must be aware that laws require reporting incidences of this disease to the appropriate Board of Health.
  • A similar history must be obtained when chlamydial conjunctivitis is suspected.
  • Clinical suspicion of venereal disease may be present at first presentation or upon treatment failure of an unsuspected case.
  • It may be desirable to have the technician, nurse, or other clinical personnel take the sexual history to avoid a sense of inappropriateness.
  • It is better to ask the patient if they wish friends or family members to leave the room for this aspect of the evaluation.

Physical Examination

Conjunctival injection may be present segmentally or diffusely. The everted inferior or superior palpebral conjunctival pattern may hold clues to the etiology.

Using slit-lamp biomicroscopy and everting both the upper and lower eyelids, follicles or papillae can be identified on the inflamed conjunctiva. Follicles, more common in the lower lid conjunctiva, have blood vessels that circumscribe the base of tiny elevated lesions. Follicles are characteristic of a hypersensitivity conjunctivitis (eg, due to brimonidine [Alphagan] or trifluorothymidine [Viroptic] drops), viral conjunctivitis, or chlamydial conjunctivitis or allergy to contact lens solution preservatives. Papillae, seen commonly in the conjunctiva of the upper lid, have vessels coming up the center of the tiny elevated lesion and are characteristic of bacterial or allergic conjunctivitis.

The discharge in bacterial conjunctivitis is typically more purulent than the watery discharge of viral or allergic conjunctivitis. Thus, there is more "mattering" of the lid margins and associated difficulty in prying the lids open following sleep. The mucopurulent discharge can appear white, yellow, or even greenish in color.

In uncomplicated bacterial conjunctivitis, slit lamp examination reveals a quiet anterior chamber that is devoid of cells and flare. The vitreous is also unaffected.

A preauricular lymph node is unusual in bacterial conjunctivitis but can be present in severe conjunctivitis caused by N gonorrhoeae. This key finding is also strongly associated with viral ocular syndromes, typically herpes simplex keratitis and epidemic keratoconjunctivitis.

Eyelid edema is often present, but it is mild in most cases of bacterial conjunctivitis. Severe lid edema in the presence of copious purulent discharge raises the suspicion for N gonorrhoeae infection.

Visual acuity is preserved in bacterial conjunctivitis as long as the cornea is intact, except for the expected mild blur secondary to the discharge and debris in the tear film. Some patients may inadvertently abrade their own corneas out of symptomatic frustration, leading to worse vision, even more discomfort, and increased morbidity. Rarely, topical anesthetic abuse can initiate or exacerbate this complication.

The pupil reacts normally in bacterial conjunctivitis. Anisocoria or a fixed pupil in the setting of a red eye should raise the suspicion for angle-closure glaucoma or iritis with posterior synechiae. [7]

Extreme unilateral dilation and tortuosity of the major conjunctival blood vessels suggests a cavernous sinus-carotid artery fistula rather than conjunctivitis.



Bacterial conjunctivitis, as long as the cornea is not affected, seldom leads to complications.

General concerns include membrane formation, severe postrecovery dry eye, and subsequent scarring of the punctum; corneal ulcer when the epithelium is not intact; and symblepharon from severe inflammation. Organisms most commonly associated with membrane formation and conjunctival scarring include adenovirus (epidemic keratoconjunctivitis [EKC]), N gonorrhea, and exotoxin-producing S pneumoniae.

In eyes with previous intraocular surgery, particularly with filtering blebs, endophthalmitis could result.