Phlyctenular keratoconjunctivitis is an inflammatory syndrome caused by a delayed (aka type-IV) hypersensitivity reaction to one or more antigens. The triggering antigen is usually a bacterial protein (particularly from ''
Staphylococcus aureus
''Staphylococcus aureus'' is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often posit ...
''), but may also be a virus, fungus (particularly ''
Candida albicans
''Candida albicans'' is an opportunistic pathogenic yeast that is a common member of the human gut flora. It can also survive outside the human body. It is detected in the gastrointestinal tract and mouth in 40–60% of healthy adults. It is usua ...
''), or
nematode.
Symptoms
* Irritation
* Discomfort or pain
* Foreign-body sensation
* Tearing
*
Blepharospasm
Blepharospasm is any abnormal contraction of the orbicularis oculi muscle. The condition should be distinguished from the more common, and milder, involuntary quivering of an eyelid, known as myokymia, or fasciculation. In most cases, blepharo ...
*
Photophobia
Photophobia is a medical symptom of abnormal intolerance to visual perception of light. As a medical symptom photophobia is not a morbid fear or phobia, but an experience of discomfort or pain to the eyes due to light exposure or by presence of ...
*
Mucopurulent discharge
Mucopurulent discharge is the emission or secretion of fluid containing mucus and pus (''muco-'' pertaining to ''mucus'' and ''purulent'' pertaining to ''pus'') from the eye, nose, cervix, vagina or other part of the body due to infection and inf ...
(rarely)
In cases where the cornea is affected, pain and photophobia are more likely,
and corneal scarring can occur (potentially impairing vision).
Presentation
The syndrome is marked by the appearance of characteristic lesions, known as phlyctenules, on the cornea and/or conjunctiva. These usually manifest as small (1 - 3
or 1 - 4
mm) raised nodules, pinkish-white or yellow in color, which may ulcerate (or, more rarely, necrose) and are often surrounded by dilated blood vessels. Corneal lesions are usually triangular in shape, with the base at the limbus and the apex pointing towards the center of the cornea.
Diagnosis
Clinical findings of Corneal lesion or corneal ulceration.
Treatment
The symptoms of phlyctenular keratoconjunctivitis are primarily treated with application of an appropriate
corticosteroid
Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are in ...
eye drop, such as
prednisolone acetate (Pred Forte) or
loteprednol (Lotemax). Loteprednol is increasingly preferred due to its lower risk of elevating
intraocular pressure
Intraocular pressure (IOP) is the fluid pressure inside the eye
Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response fu ...
. The corticosteroid suppresses the immune response, reducing inflammation and improving most symptoms.
The causative agent (i.e. the source of the antigen that triggered the hypersensitive immune response) should also be identified. ''
Staphylococcus aureus
''Staphylococcus aureus'' is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often posit ...
'' is usually the primary suspect, along with ''
Mycobacterium tuberculosis'' in areas where TB is
endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found els ...
, followed by ''
Chlamydia trachomatis
''Chlamydia trachomatis'' (), commonly known as chlamydia, is a bacterium that causes chlamydia, which can manifest in various ways, including: trachoma, lymphogranuloma venereum, nongonococcal urethritis, cervicitis, salpingitis, pelvic infl ...
''. Active bacterial infections may be treated with a
topical antibiotic
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention o ...
or a combination antibiotic-steroid eye drop, such as
tobramycin/dexamethasone (Tobradex).
An oral
tetracycline antibiotic
Tetracyclines are a group of broad-spectrum antibiotic compounds that have a common basic structure and are either isolated directly from several species of ''Streptomyces'' bacteria or produced semi-synthetically from those isolated compounds. T ...
(such as
doxycycline) may be used in systemic or particularly severe/intractable infections.
Erythromycin
Erythromycin is an antibiotic used for the treatment of a number of bacterial infections. This includes respiratory tract infections, skin infections, chlamydia infections, pelvic inflammatory disease, and syphilis. It may also be used du ...
may be an effective alternative, especially in
pediatric
Pediatrics ( also spelled ''paediatrics'' or ''pædiatrics'') is the branch of medicine that involves the medical care of infants, children, adolescents, and young adults. In the United Kingdom, paediatrics covers many of their youth until th ...
cases where the side effects of tetracyclines are unacceptable.
Artificial tears can reduce dryness and discomfort from corneal lesions.
Photophobic
Photophobia is a medical symptom of abnormal intolerance to visual perception of light. As a medical symptom photophobia is not a morbid fear or phobia, but an experience of discomfort or pain to the eyes due to light exposure or by presence of ...
discomfort can be mitigated with dark
sunglasses
Sunglasses or sun glasses (informally called shades or sunnies; more names below) are a form of protective eyewear designed primarily to prevent bright sunlight and high-energy visible light from damaging or discomforting the eyes. They can ...
.
See also
*
Blepharitis
Blepharitis is one of the most common ocular conditions characterized by inflammation, scaling, reddening, and crusting of the eyelid. This condition may also cause swelling, burning, itching, or a grainy sensation when introducing foreign objects ...
*
Allergic conjunctivitis
Allergic conjunctivitis (AC) is inflammation of the conjunctiva (the membrane covering the white part of the eye) due to allergy. Although allergens differ among patients, the most common cause is hay fever. Symptoms consist of redness (mainly due ...
*
Conjunctivitis
Conjunctivitis, also known as pink eye, is inflammation of the outermost layer of the white part of the eye and the inner surface of the eyelid. It makes the eye appear pink or reddish. Pain, burning, scratchiness, or itchiness may occur. The ...
*
Keratitis
Keratitis is a condition in which the eye's cornea, the clear dome on the front surface of the eye, becomes inflamed. The condition is often marked by moderate to intense pain and usually involves any of the following symptoms: pain, impaired e ...
*
Keratoconjunctivitis
Keratoconjunctivitis is inflammation ("-itis") of the cornea and conjunctiva.
When only the cornea is inflamed, it is called ''keratitis''; when only the conjunctiva is inflamed, it is called ''conjunctivitis''.
Causes
There are several potentia ...
*
Corneal abrasion
Corneal abrasion is a scratch to the surface of the cornea of the eye. Symptoms include pain, redness, light sensitivity, and a feeling like a foreign body is in the eye. Most people recover completely within three days.
Most cases are due to ...
References
{{reflist
Eye diseases