What is Inclusion Conjunctivitis ?
Adult inclusion conjunctivitis or Paratrachoma results due to infection by obligate intracellular bacterium, Chlamydia trachomatis (serotypes D to K), which causes chronic follicular conjunctivitis (follicular conjunctivitis lasting for more than 16- 28 days). These organisms infect the epithelium of mucoid surfaces and were once identified as the trachoma-inclusion conjunctivitis agents (TRIC agents). These organisms can also infect a neonate during birth and may lead to neonatal conjunctivitis.
Chlamydia trachomatis also includes the agents of classic trachoma (serotypes A, B, Ba and C). Lymphogranuloma venereum, a sexually transmitted infection, is caused by Chlamydia trachomatis (serotypes L1 to L3) which infect tissues deeper to the epithelium.
Adult inclusion conjunctivitis is transmitted sexually (oro-genital activities) or from hand-to-eye contact. Gonorrhoea is the most common co-infection associated with adult inclusion conjunctivitis. Rarely, adult inclusion conjunctivitis is transmitted through eye-to-eye contact (e.g. by sharing mascara).
Inclusion Conjunctivitis Symptoms
Adult inclusion conjunctivitis presents as a unilateral (less commonly bilateral) affliction of eye.
Symptoms do not always exist with adult inclusion conjunctivitis in large number of patients and is often transmitted unknowingly.
Almost half of patients with adult inclusion conjunctivitis do not have a systemic infection of Chlamydia. In addition to eye, Chlamydiae are found in parts of the body with mucosal membrane such as respiratory tract and the genitourinary tract.
Symptoms of adult inclusion conjunctivitis may wax and wane and the patient may be asymptomatic.
Patient may present with symptoms like:-
Ocular (Eye) symptoms:
- Red eye.
- Muco-purulent discharge.
- Sticking of eyelashes on awakening.
- Watering.
- Itching.
- Irritation of eyes.
- Foreign body sensation.
- Photophobia or intolerance to light.
- Pain.
- Swelling of eyelids.
Systemic symptoms:
- Urethritis in males.
- Genito-urinary symptoms viz. urethritis, vaginal discharge in females.
- Mild ear infection on same side of infected eye.
-Mild pre-auricular lymphadenopathy.
Inclusion Conjunctivitis Causes
Chlamydia trachomatis causes trachoma (serotypes A, B, Ba and C) and also genital infections (serotypes D to K) and disease Lymphogranuloma venereum (serotypes L1 to L3).
Infection with genital serotypes D to K can cause isolated episodes of ophthalmia neonatorum in infants or inclusion conjunctivitis in adults. The incubation period for adult inclusion conjunctivitis is 4-12 days.
Genital serotypes do not cause trachoma blindness since they do not enter stable transmission cycles within communities. Serotypes D to K occasionally cause subacute follicular conjunctivitis but conjunctival scarring is rare.
Usually, adult inclusion conjunctivitis is observed in young sexually active people. It is most common in persons aged 15-35 year
Inclusion Conjunctivitis Diagnosis
Diagnosis of adult inclusion conjunctivitis depends upon clinical presentation and laboratory diagnosis.
Women with chlamydial infection often have a concomitant urethritis or vaginal discharge secondary to chronic vaginitis and/or cervicitis. Men may have symptomatic or asymptomatic urethritis.
Often, history of patient reveals that this condition has been going on for several weeks. Usually, bacterial infections run a much shorter clinical course of one to two weeks only.
Adult inclusion conjunctivitis usually presents as unilateral (less commonly bilateral) conjunctival redness with mucopurulent discharge, papillary hypertrophy and a predominant follicular conjunctivitis. Untreated disease has a chronic remittent course and may last for months together.
Knowledge of duration of symptoms, any prior treatment taken and recent and not-so-recent history of sexual exposure is important in diagnosis.
Clinical features:
Patient may have tender enlarged pre-auricular lymph node.
Slit-lamp examination by an eye-specialist is required.
Ocular clinical features may include:-
- Inferior tarsal conjunctival follicles.
- Papillary hypertrophy and injection in superior tarsal conjunctiva.
- Keratitis (may develop during second week after onset). Corneal involvement includes:
Superficial punctate keratitis.
Small marginal or central infiltrates.
Sub-epithelial infiltrates (tend to be more peripheral).
Superior limbus pannus.
- Limbal swelling.
- Iritis (may develop in late stages of disease).
Laboratory diagnosis:
- Nucleic acid amplification tests (NAATs): Nucleic acid amplification test is the best laboratory technique, of which polymerase chain reaction (PCR) is an example.
NAATs have high sensitivity and specificity but are expensive and not widely available.
- Giemsa cytology: Giemsa cytology is microscopic examination of stained conjunctival scrapings for basophilic intra-cytoplasmic epithelial inclusion bodies (Halberstaedter-Prowazek bodies). This test is highly specific but has low sensitivity.
- Chlamydial culture: Chlamydial cultures may be obtained from conjunctiva.
- Direct fluorescent antibody (DFA) assay: Direct fluorescent antibody assay of conjunctival smears is less sensitive than NAATs.
- Enzyme immunoassay (EIA): Enzyme immunoassay of conjunctival smears is also less sensitive than NAATs
- Serum immunoglobulin G (IgG) titers: Serum immunoglobulin G (IgG) titers may be obtained against chlamydia species.
Adult inclusion conjunctivitis should be differentiated from conditions like:
- Trachoma.
- Epidemic kerato-conjunctivitis.
- Superior limbic kerato-conjunctivitis.
- Allergic conjunctivitis.
- Bacterial conjunctivitis.
- Viral conjunctivitis.
- Molluscum contagiosum.
- Complications of contact lens use.
Inclusion Conjunctivitis Complications
Complications of adult inclusion conjunctivititis may be:
Systemic complications:
- Urethritis, vaginitis and mucopurulent cervicitis in females.
- Pelvic inflammatory disease (PID).
- Perihepatitis (Fitz-Hugh-Curtis syndrome) in women with PID.
- Urethritis in males.
- Epididymitis in males.
- Co-infection with another sexually transmitted disease like gonorrhoea.
- Reiter syndrome (syndrome of urethritis, conjunctivitis and reactive arthritis) may be associated with chlamydial infection.
Ocular complications:
In adult inclusion conjunctivitis secondary to genital tract infection, there is not the same likelihood of re-infection. Thus, conjunctival scarring is rarely a complication of adult inclusion conjunctivitis, although micro-pannus (superficial fibrovascular proliferation that extends 1-2 mm beyond normal vascular arcade) and micro-ulceration of the cornea following punctate keratitis may rarely take place.
Iritis may develop in late stages of disease.
Inclusion Conjunctivitis Prevention
To prevent adult inclusion conjunctivitis, patients should follow safe sexual practices.
Patients should be educated about the risks of sexually transmitted diseases