Phlyctenulosis characterized by
hyperemic corneal phlecten

ICD-10 Diagnosis Codes:

H16.251–Phlyctenular keratoconjunctivitis, right eye
H16.252–Phlyctenular keratoconjunctivitis, left eye
H16.253–Phlyctenular keratoconjunctivitis, bilateral


Phlyctenular Keratoconjunctivitis




Phlyctenular keratoconjunctivitis is an inflammation of the cornea and conjunctiva caused by microbial antigens.

Phlyctenlar keratoconjunctivitis is a form of bacterial hypersensitivity-mediated corneal disease.  Phlyctenular keratoconjunctivits is also called phlyctenulosis and other possible etiologies include tuberculosis and Chlamydia.

In most patients, the condition is the result of a reaction with staphylococcal cell wall antigen (i.e., adverse reaction to toxic proteins found on the ocular surface in chronic blepharoconjunctivitis).  

The histopathological changes in phlyctenular keratoconjunctivitis begin with the body’s immune response to the microbial antigens.  First, accumulations of lymphoid tissue form nodules on the bulbar conjunctiva known as phlyctenules.  Then, the conjunctiva surrounding the phlyctenules becomes hyperemic.

Conjunctival phlyctenules may persist for several weeks and are usually self-limiting.  However, they may ulcerate as the disease progresses but usually they heal without scarring. In more severe presentations, the conjunctival phlyctenules migrate into the cornea and are then called corneal phlyctenules.

Structural Damage to the Eye

  • Small white nodule forms on the bulbar conjunctiva
  • Surrounding conjunctiva becomes hypermic
  • Disease progression results in the corneal migration of the conjunctival phlyctenule
  • Lesion is now called a corneal phlyctenule
  • Corneal neovascularization may occur
  • Corneal scarring may occur
  • Corneal ulceration may occur
  • Corneal perforation may occur

Functional Damage to the Eye

  • Decreased visual acuity can occur as a result of the compromised corneal epithelium

The main goal of the diagnostic evaluation in a patient with phlyctenular keratoconjunctivitis is to accomplish the following:

  • To establish the diagnosis of phlyctenular keratoconjunctivitis
  • To determine any inciting etiologies
  • To prescribe appropriate therapy
  • To prevent complications

To obtain the information required to determine a clinical diagnosis of phlyctenulosis and prescribe a treatment program, the following service components of a medical eye examination should be performed:

  • Patient history
  • General medical observation
  • Adnexal examination
  • External ocular examination with biomicroscopy

In children and young adults, a purified protein derivative (PPD) tuberculin skin test should be considered in the diagnostic evaluation.  If tuberculosis is supsected or if the PPD is positive, a chest X-ray is advised.

Patient History

Patients with phlyctenulosis may present with any of the following symptoms:

  • Watery eyes
  • Red eyes
  • Ocular discomfort
  • Photophobia
  • Eye pain
  • Blepharospam
  • History of previous episodes
  • History of styes or chalazion

External Ocular Examination with Biomicroscopy

Patients with phlyctenulosis may present with abnormal clinical signs in any of the following anatomical areas:

  • Tear film
  • Conjunctiva
  • Cornea
DG37031Pic01 Clinical Apperance of the Cornea

  • 18-year-old black male with a 1-month history of red eye
  • White nodule known as a corneal phlyctenule
  • Lesion is migrating towards the central corneal region
  • Wedge-shaped corneal neovascularization is present behind the leading edge of the lesion
  • Dilated conjunctival blood vessels approach the corneal phlyctenule
DG37031Pic02 Clinical Appearance of the Cornea

  • Large corneal phlyctenule
  • Most common location is the inferior cornea between 4 and 8 o’clock
  • Associated keratopathy is a common finding
  • Corneal neovascularization behind the leading edge of the lesion is usually present
  • Corneal phlyctenules are also called corneal phlycten
DG37031Pic04 Clinical Appearance of the Cornea

  • Same patient seen in images from above
  • Phlyctenular keratoconjunctivitis twelve days after topical steroid treatment with Pred Forte

There is no classification system for phlytenular keratoconjunctivitis.

CT_ICD9_372-51_Pic06_061809 Inflamed Pinguecula

  • Pingueculitis is not characterized by corneal infiltration


DG37003Pic01 Infectious Keratitis

  • Characterized by underlying subepithelial infiltration
DG37031Pic08 Sterile Peripheral Corneal Infiltrate

  • Corneal infiltrates usually associated with contact lens wear
  • This condition is not characterized by ulceration and the lesion does not migrate into the cornea
DG37031Pic09 Marginal Corneal Ulcer

  • This form of keratitis has a similar etiology, but is not characterized by conjunctival nodules
DG37031Pic10 Herpes Simplex Keratitis

  • This condition may produce a stromal infiltrate and corneal neovasculariztion that is similar in appearance to phlyctenulosis
DG37031Pic11 Vernal Conjunctivitis

  • This condition is characterized by giant papillae under the eyelid
  • There may be multiple lesions at the limbus called Horner-Trantas dots that are similar in appearance to the nodules found in phylctenulosis

Since phlyctenular keratoconjunctivitis is a hypersensitivity reaction to microbial toxins commonly seen with chronic staphloccocal blepharoconjunctivitis, treatment options must include treating these inciting conditions.

Palliative Treatment

  • Lid hygeine regimen
  • Artificial tears for comfort

Pharmacologic Treatment: Topical Medications

  • Steroids in the presence of conjunctival involvement (i.e. Pred Forte q.i.d)
  • Antibiotic in the presence of bacterial corneal ulcer (i.e. fluoroquinolones q.i.d)
  • Antibiotic ointment (i.e. Erythromycin or Bacitracin qhs)
  • Cycloplegic in severe corneal involvement
    • Homatropine 2% or 5%  t.i.d. – q.i.d.
    • Scopolamine 0.25%  b.i.d. – q.i.d.

Pharmacologic Treatment: Oral Medications

  • Oral antibiotic (i.e. Doxcycline 100 mg p.o. q.d. to b.i.d or Erythromycin 250 mg p.o. q.d. to b.i.d.) 

Systemic Treatment

  • If the PPD or chest X-ray is positive for TB, refer the patient for further management of the the systemic cause

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