Last updated on November 1st, 2017 at 07:58 am
Phlyctenular keratoconjunctivitis is a nodular inflammation of the cornea or conjunctiva that arises from a hypersensitivity response to a foreign antigen. Prior to the 1950s, phlyctenular keratoconjunctivitis provided as a consequence of a hypersensitivity reaction to tuberculin protein due to the high occurrence of tuberculosis. It was typically seen in poor, undernourished kids with positive tuberculin skin test.
Following enhancements in public health efforts and decreasing rates of tuberculosis, there was a decrease in phlyctenular keratoconjunctivitis and subsequent patients were discovered to have negative tuberculin tests. In the United States, microbial proteins of Staphylococcus aureus are the most typical causative antigens in phlyctenular keratoconjunctivitis. Risk factors for S. aureus direct exposure include chronic blepharitis and suppurative keratitis. Phlyctenular keratoconjunctivitis is a typical cause of pediatric referrals as it takes place mainly in children from 6 months to 16 years of ages. There is a higher occurrence in women and greater incidence during spring.
Causes of Phlyctenulosis
Phlyctenular keratoconjunctivitis is postulated to take place secondary to an allergic, hypersensitivity reaction at the cornea or conjunctiva, following re-exposure to an infectious antigen that the host has actually been previously sensitized to. Antigens of Staphylococcus aureus and Mycobacterium tuberculosis are most frequently associated; nevertheless, Chlamydia, Streptococcus viridians, Dolosigranulum pigram and digestive parasites including Hymenolepis nana have actually likewise been reported as causative agents.
Histologically, scrapings from impacted eyes with phlyctenular keratoconjunctivitis infiltrates show primarily helper T cells, as well as suppressor/cytotoxic T-lymphocytes, monocytes and Langerhans cells. The majority of cell scrapings were HLA-DR favorable. The presence of antigen presenting cells (Langerhans cells), monocytes and T cells support the reasoning that phlyctenular keratoconjunctivitis is likely due to a postponed cell-mediated reaction. Phlyctenular keratoconjunctivitis might have an association with ocular rosacea, a skin problem that may have a similar underlying type IV hypersensitivity origin. Previous reports of phlyctenular keratoconjunctivitis with associated asthma and allergies likewise support the concept of a transformed immune system contributing to the pathogenesis.
Symptoms and Diagnosis of Phlyctenulosis
The scientific discussion of phlcytenulosis depends on the location of the sore in addition to the underlying etiology. Conjunctival sores may cause just mild to moderate inflammation of the eye, while corneal sores typically might have more severe pain and photophobia. More severe light sensitivity may likewise be related to tuberculosis related phlyctenules compared to S. aureus associated phlyctenules. Phlyctenules can occur anywhere on the conjunctiva however are more common in the interpalpebral fissure and are regularly kept in mind along the limbal area. They typically present with a gelatinous, nodular sore with significant injection of the surrounding conjunctival vessels. The sores might reveal some degree of ulceration and staining with fluorescein as they advance. Sometimes, numerous 1-2mm blemishes may exist along the limbal surface area.
Corneal phlyctenules likewise start along the limbal area and often deteriorate to corneal ulcer and neovascularization. In some instances, the phlyctenule will progress throughout the corneal surface due to repeated episodes of inflammation along the central edge of the lesion. These “marching phlyctenules” show an elevated leading edge tracked by a leash of vessels.
The medical diagnosis of phlyctenular keratoconjunctivitis is made based upon history and medical exam findings. The underlying contagious etiology requires further investigation when the possibility of tuberculosis or chlamydia is presumed. Chest radiographs, purified protein derivative skin testing or QuantiFERON gold screening must be bought for patients with a history of travel to tuberculosis endemic regions or symptoms consistent with tuberculosis infection. For patients presumed of having chlamydia, immunofluorescent antibody testing and PCR of conjunctival swabs provide quick and accurate screening. If positive, appropriate systemic treatment of these infections is needed in addition to screening and possible treatment of close contacts.
- Acne Rosacea Keratitis
- Rosacea Keratoconjunctivitis
- Nodular Episcleritis
- Salzmann’s Nodules
- Irritated Pigueculum/Pterygium
- Vernal Keratoconjunctivitis
- Transmittable Corneal Ulcer with Vascularization
- Catarrhal Ulcer
- Peripheral Ulcerative Keratitis
Phlyctenular nodules can result in ulcer, scarring and moderate to moderate vision loss. Although uncommon, corneal perforation is possible too.
How Is Phlyctenulosis Treated
The first line of treatment for phlyctenulosis (phlyctenular keratoconjunctivitis) is to reduce the inflammatory action. Phlyctenulosis is typically responsive to topical steroids. In cases with multiple recurrences or that end up being steroid reliant, topical cyclosporine A is an efficient treatment alternative. Using cyclosporine A may minimize the sequelae of long term steroid use such as cataracts, ocular hypertension and reduced wound healing. In cases with corneal ulcer, pretreatment or concurrent use of an antibiotic is suggested. Corneal cultures might also be thought about prior to beginning treatment.
In addition to dealing with the inflammatory reaction, it is important to reduce the source of antigens prompting the inflammation. This normally needs treating the associated blepharitis or underlying contagious procedure. In cases of blepharitis, lid hygiene with warm compresses and cover scrubs ought to be begun. One research study found that 1.5% topical azithromycin was effective in dealing with phlyctenular keratoconjunctivitis with underlying ocular rosacea. Adjunctive treatment with oral doxycycline may also be of benefit. In children under the age of 8, erythromycin is preferred to avoid dental discoloration from tetracycline use.
In patients with infectious diseases such as tuberculosis and chlamydia, the underlying infections should be appropriately dealt with and treated appropriately. Chlamydia induced phlyctenular keratoconjunctivitis must be treated with azithromycin or doxycycline. Patients with favorable tuberculin tests ought to be referred to receive proper systemic treatment of tuberculosis. Close contacts must likewise be assessed and dealt with fittingly.
In rare circumstances of corneal perforation, surgical treatment may be needed. Choices for treating peripheral perforations consist of corneal gluing, amniotic membrane grafting, or corneal patch grafts.