The human eye has a complex anatomy comprising several layers. The episclera is the layer of connective tissue containing a network of arteries and veins which lies above the white of the eye (sclera).
Episcleritis is a condition of the eye wherein the episclera becomes inflamed. It may manifest as a consequence of a preexisting systemic disease which also causes inflammation of other parts of the body. Alternatively, the episclera can become inflamed for no apparent reason. Most commonly, those with the condition only experience episcleritis of one eye, though it can affect both eyes simultaneously. Generally, episcleritis does not cause vision loss but can cause discomfort and eye redness.1
The American Academy of Ophthalmology states that there are two broad types of episcleritis – simple and nodular. For all types of episcleritis, the diagnosis must be made after a thorough physical examination of the eye. Most mild cases usually improve without medical intervention, but your healthcare provider may recommend treatment options to help speed up the recovery process.
Episcleritis is not to be confused with scleritis which is a much more serious condition wherein visual acuity can be temporarily or permanently decreased. See your healthcare provider urgently if you suspect that you have this condition.2
In this article, you will find information regarding the types, causes, signs and symptoms of episcleritis and what to expect when visiting a healthcare provider.
Types of episcleritis
Episcleritis can be simple or nodular. Simple episcleritis can be subdivided further into diffuse or sectoral episcleritis.
These categories identify the extent of redness seen in the affected eye. If the area of redness covers a large proportion of the episclera, it is classed as diffuse. If the redness is limited to a distinct area, it is called sectoral episcleritis.
Nodular episcleritis consists of a raised area of inflammation on the episclera - a nodule. This type of episcleritis typically comes on gradually and is more painful in comparison to simple episcleritis. It is also less common than simple episcleritis, accounting for between 15% to 30% of all episcleritis cases.1
Causes of episcleritis
As mentioned above, most cases of episcleritis occur without any apparent cause (idiopathic). Around 26% to 36% of cases occur in people with an existing systemic disease, which is usually inflammatory and/or autoimmune in nature. Of these cases, rheumatoid arthritis is the most common underlying condition. Some of these diseases are listed below.1
- Rheumatoid Arthritis
- Inflammatory Bowel Disease (Ulcerative Colitis/Crohn’s Disease)
- Reactive Arthritis
- Systemic Lupus Erythematosus
- Ankylosing Spondylitis
- Polyarteritis Nodosa
- Behcet disease
Some infections are also associated with episcleritis:1
- Lyme Disease
- Cat Scratch fever
Signs and symptoms of episcleritis
In 80% of cases, episcleritis only affects one eye. In the remaining 20% of cases, both eyes are affected.1
The signs and symptoms of episcleritis include:1
- Discomfort, tenderness or mild pain over the affected area of the eye
- Red/Pink discolouration of the eye, which can appear suddenly or gradually
- Swelling of the eyelid
If the above is accompanied by severe pain, photophobia, reduced visual acuity and/or eye discharge, it is important that a diagnosis of other serious eye conditions, such as scleritis, is ruled out.
The redness seen in episcleritis can cause it to be mistaken for conjunctivitis (pink eye). However, conjunctivitis also causes ocular discharge and increased tear production of the eye, which isn’t typical in episcleritis.
Management and treatment for episcleritis
Episcleritis can improve within 2 to 21 days without treatment. The use of medications may also be recommended by your healthcare provider in order to reduce the severity of the symptoms. These include:1
- Topical lubricants, i.e. artificial tears
- Oral Non-steroidal anti-inflammatory drugs (NSAIDs)
- Topical NSAIDs
- Topical corticosteroid eye drops
In at least 30% of patients with systemic disease, episcleritis will reoccur.1 In these cases, it is important that an eye doctor (ophthalmologist) is involved in managing eye health, and the appropriate specialist physicians are involved in managing the systemic disease.
A diagnosis of episcleritis can only be made after an eye examination is performed by your healthcare provider. As part of this, the clinician may use special eye drops containing phenylephrine to assess the blood vessels in the eye. In episcleritis, the vessels become blanched, and the eye will appear more white compared to its appearance prior to the application of the drops. They may also look at your eye using a slit lamp.1
Your healthcare provider will also take a thorough history and perform a review of other possible related symptoms, such as joint pain, muscle weakness, rashes and infection, which may indicate a systemic cause.
If one of the inflammatory, autoimmune or infectious conditions mentioned previously is suspected, or if episcleritis occurs more than once, your clinician may also advise for further testing to be performed to determine if there is an underlying diagnosis.
In rare cases where the diagnosis of episcleritis cannot be confirmed or ruled out after an eye examination, or when the condition does not improve with treatment, and a more serious systemic condition is suspected, a tissue biopsy may be performed.1
How can I prevent episcleritis?
There is no documented way of preventing episcleritis from occurring.
How common is episcleritis?
According to the Cleveland Clinic, the incidence of episcleritis in the United States of America is 41 in 100,000.
Who is at risk of episcleritis?
Episcleritis can affect anyone, though it is more common in women and those assigned female at birth, and those with a systemic disease which predisposes them to inflammatory conditions.1
When should I see a doctor?
See a doctor urgently if you are concerned about a change in your vision, as it may be a sign of a more serious condition such as scleritis.
If you are worried about any of the symptoms mentioned above, see your provider as soon as possible so that they can perform an eye examination and advise you on the best course of treatment.
Episcleritis is a condition which causes redness and mild discomfort of the eye and usually resolves on its own. Though the cause is not usually known, it can sometimes be associated with another health condition. A clinician will be able to diagnose episcleritis using a series of examinations and tests and will also be able to advise on any further testing if required. See a healthcare provider urgently if you experience severe eye pain or blurring of vision, as these can be signs of scleritis, which is a more serious eye condition.
- Schonberg S, Stokkermans TJ. Episcleritis. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 [cited 2023 Jun 16]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK534796/
- Lagina A, Ramphul K. Scleritis. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 [cited 2023 Jun 16]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK499944/