Phlyctenular keratoconjunctivitis (phlyctenulosis)

ETIOLOGY

Phlyctenular keratoconjunctivitis represents an inflammatory process secondary to an allergic hypersensitivity response of the conjunctiva and cornea. Phlyctenular keratoconjunctivitis results from a hypersensitivity reaction to bacterial antigens, primarily Staphylococcus aureus, but has also been associated with

Mycobacterium tuberculosis, Chlamydia sp., Candida albicans, and some parasites (Ascaris lumbricoides, Ancylostoma duodenale). There has also been an association of phlyctenular keratoconjunctivitis in patients with rosacea, Behçet’s disease, and human immunodeficiency virus (HIV). It is more common in females especially in the first two decades of life.

The exact mechanism by which the elevated, hard, yellowish-white nodules (phlyctenules) are produced is unclear. Since their presence is associated with foreign antigens, it is believed to represent a delayed allergic hypersensitivity reaction.40 The presence of accompanying lid disease, with a stapholococcal blepharitis, is a frequent finding in children with phlyctenular keratoconjunctivitis.

CLINICAL PRESENTATION

The classic signs of phlyctenular keratoconjunctivitis are conjunctival injection with the presence of phlyctenules, usually at the limbus. The phlyctenules can also be found on the conjunctiva away from the limbus, as well as on the clear cornea. The patients will typically present with a chronically inflamed red eye, lasting longer than the natural history of viral or bacterial conjunctivitis of 10–14 days, with most of the conjunctival injection surrounding the phlyctenule. The patient may also have failed to improve with the use of a topical antibiotic. Their symptoms may include epiphora, ocular irritation, and a mucopurulent, and/or ropey discharge. The phlyctenules can measure 1–3 mm, and can be bilateral. When there are corneal phlyctenules present, the symptoms tend to be more severe.

MANAGEMENT/TREATMENT

The treatment of phlyctenular keratoconjunctivitis must be aimed at eliminating the antigen that is causing the eye to exhibit the delayed hypersensitivity reaction. The use of good lid hygiene is imperative if blepharitis is present. Lid scrubs two to three times a day, along with the use of a topical antibiotic ointment, will help to get rid of the offending organism and the hypersensitivity reaction. In mild cases, this along with the use of lubricating drops may alleviate the problem completely. In moderate to severe cases of phlyctenular keratoconjunctivitis, especially with significant corneal involvement, the use of a topical steroid, or a topical steroid/antibiotic combination, may be necessary. Because these lesions are sensitive to treatment with a topical steroid, the child can show rapid improvement in signs and symptoms. However, the patient may show exacerbation of signs if the antigen is still present, and the steroids are tapered too quickly. Because the use of topical steroids in these patients may be associated with significant sequelae, management of the treatment should be directed by an ophthalmologist. If there is a significant blepharitis present, the addition of doxycycline to the treatment regime can be considered, but is contraindicated in children younger than 8 years due to the side-effects on the teeth and bones. In cases of phlyctenular keratoconjunctivitis that do not show a significant blepharitis or otherwise appear atypical, a complete workup of the patient, including a purified protein derivative (PPD), chest X-ray, HIV titer, and HLA typing should be performed.

PROGNOSIS

Phlyctenular keratoconjunctivitis can often be controlled and symptoms improved with local treatment. In more severe cases, vision can be reduced secondary to corneal scarring.

Ophthalmia neonatorum

ETIOLOGY

Ophthalmia neonatorum represents a distinct form of conjunctivitis seen during the first 4 weeks postpartum. If conjunctivitis is suspected during this time period, consultation with an ophthalmologist, neonatologist, and infectious disease specialist is highly recommended.

The most common etiologies of ophthalmia neonatorum are chemical conjunctivitis (hyperemia and mucoid discharge during the first 24 hours postpartum) caused by silver nitrate or erythromycin prophylaxis, herpes simplex, Neisseria gonorrhoeae and N. meningitidis, and Chlamydia trachomatis

(85).26 The four latter etiologies are all potentially visionand eye-threatening and will require aggressive treatment. These organisms must be part of the clinician’s differential diagnosis for the newborn early on after delivery, especially if the mother has experienced a spontaneous rupture of membranes, and delivery has been intentionally delayed by the obstetrician. With access of these organisms to the unborn child through the cervix and into the uterus, without the protection of an intact amniotic sac, a newborn infant can exhibit the signs and symptoms of an infection earlier than would be expected.

CLINICAL PRESENTATION

The onset of the conjunctivitis may occur in the first few days of life but may be delayed for up to 1 month (Table 11). Infants may present with mild conjunctival hyperemia and discharge or with marked conjunctival swelling and copious discharge. Some cases may lead to rapid corneal ulceration and perforation of the eye. Systemic infection can cause sepsis and meningitis.

DIAGNOSIS

Chemical conjunctivitis is a mild irritation and redness of the conjunctiva occurring in the first 24 hours after instillation of silver nitrate prophylaxis of ophthalmia neonatorum. These symptoms can suggest the onset of

85

85 Ophthalmia neonatorum caused by chlamydia.(FromVernon S,Differential Diagnosis in Ophthalmology,Manson Publishing.)

conjunctivitis in the newborn, but the condition will improve spontaneously by the second day.

During the first 4 weeks postpartum, cultures and Gram stains of ocular discharge are important before initiating any treatment. The physician must remember that he or she has a minimum of three patients who must be investigated: the newborn baby, the mother, and all of the mother’s sexual partners. Unless a suspicion of a severe etiology of an ocular infection is maintained during the ophthalmia neonatorum period, significant and devastating ocular and visual sequelae can occur.

MANAGEMENT/TREATMENT

Treatment is based on the causative organism. Treatment of gonococcal ophthalmia neonatorum includes systemic ceftriaxone. Neonatal chlamydial disease should also be

treated systemically due to the risk of pneumonia. The treatment of choice is oral erythromycin, 50 mg/kg per day in four divided doses for 14 days. Topical treatment is not effective.

Prophylaxis for gonorrheal ophthalmia neonatorum with 2% silver nitrate was first introduced by Crede in 1880. It significantly reduced the incidence of gonorrheal conjunctivitis and is still used in many places today. In other areas it has been replaced by erythromycin and tetracycline ointments, which are effective against both Gonococcus and trachoma inclusion conjunctivitis agent (TRIC). Povidone–iodine drops have been shown effective and less toxic when compared to erythromycin or silver nitrate ointment, and may be particularly useful in developing countries due to the low cost.

Cornea

Brandon D. Ayres, MD

•Introduction

•Congenital corneal opacity

Embryology Peters anomaly Sclerocornea

Congenital dermoid Birth trauma

Congenital hereditary endothelial dystrophy

Congenital hereditary stromal dystrophy

Posterior polymorphous membrane dystrophy

•Metabolic diseases

Mucopolysaccharidosis Hurler’s syndrome (MPS I-H) Scheie’s syndrome (MPS I-S) Hunter’s syndrome (MPS II) Morquio’s syndrome (MPS IV

A and B)

Maroteaux–Lamy syndrome (MPS VI A and B)

Sly’s syndrome (MPS VII) Idiopathic mucopolysaccharidoses Mucolipidosis

Sialidosis (ML I) I-Cell disease (ML II)

Pseudo-Hurler dystrophy (ML III) ML IV

•Miscellaneous metabolic diseases

Fabry’s disease Cystinosis Tyrosinemia

•Infectious diseases

Herpes simplex virus (HSV) Congenital syphilis

Rubella