Phlyctenular keratitis.

Corneal involvement may occur secondarily from extension of conjunctival
phlycten; or rarely as a primary disease. It may present in two forms: the 'ulcerative phlyctenular keratitis' or 'diffuse infiltrative keratitis'.

A. Ulcerative phlyctenular keratitis may occur in the following three forms:
1. Sacrofulous ulcer is a shallow marginal ulcer formed due to breakdown of small limbal phlycten. It differs from the catarrhal ulcer in that there is no clear space between the ulcer and the limbus and its
  long axis is frequently perpendicular to limbus. Such an ulcer usually clears up without
leaving any opacity.

2. Fascicular ulcer has a prominent parallel leash of blood vessels (Fig. 1). This ulcer usually remains superficial but leaves behind a bandshaped
superficial opacity after healing.
                        

Fig. 1. Fascicular corneal ulcer.

                      


3. Miliary ulcer. In this form multiple small ulcers are scattered over a portion of or whole of the cornea.

B. Diffuse infiltrative phlyctenular keratitis may
appear in the form of central infiltration of cornea with characteristic rich vascularization from the periphery, all around the limbus. It may be superficial or deep.

Clinical course is usually self-limiting and phlycten disappears in 8-10 days leaving no trace. However, recurrences are very common.

Differential diagnosis
Phlyctenular conjunctivitis needs to be differentiated from the episcleritis, scleritis, and conjunctival foreign body granuloma. Presence of one or more whitish raised nodules on the bulbar conjunctiva near the limbus, with
hyperaemia usually of the surrounding conjunctiva, in a child living in bad hygienic conditions (most of the times) are the diagnostic features of the
phlyctenular conjunctivitis.

Management
It includes treatment of phlyctenular conjunctivitis by local therapy, investigations and specific therapy aimed at eliminating the causative allergen and general measures to improve the health of the child.
1. Local therapy.
i. Topical steroids, in the form of eye drops or ointment (dexamethasone or betamethasone) produce dramatic effect in phlyctenular keratoconjunctivitis.

ii. Antibiotic drops and ointment should be added to take care of the associated secondary infection (mucopurulent conjunctivitis).

iii. Atropine (1%) eye ointment should be applied once daily when cornea is involved.

2. Specific therapy. Attempts must be made to search and eradicate the following causative conditions:
i. Tuberculous infection should be excluded by Xrays chest, Mantoux test, TLC, DLC and ESR. In case, a tubercular focus is discovered, antitubercular treatment should be started to combat the infection.

ii. Septic focus, in the form of tonsillitis, adenoiditis, or caries teeth, when present should be adequately treated by systemic antibotics and necessary surgical measures.

iii. Parasitic infestation should be ruled out by repeated stool examination and when discovered should be adequately treated for complete eradication.

3. General measures aimed to improve the health of
child are equally important. Attempts should be made
to provide high protein diet supplemented with
vitamins A, C and D.