Blepharoconjunctivitis

Etiology

It is difficult to separate the cause of blepharoconjunctivitis from the cause of blepharitis. This is due to the proximity of ocular structures and the often rapid involvement of the conjunctiva in blepharitis.[8] Blepharocojunctivitis can be caused by a variety of issues and is often multifactorial. In the acute form, it is useful to categorize the causes by clinical features. If the onset is acute with ulcerating features, this points to an infective process, with the most common organism being Staphylococcus. However, if the onset is acute with no ulceration, this points to an allergic process. It is important to note, however, that the lack of ulcers does not exclude infection as this sign is poorly specific.

If the onset is chronic, one can categorize the causes via the anatomy involved – posterior versus angular versus anterior. Meibomian gland dysfunction is often the culprit in blepharoconjunctivitis involving the posterior aspect of the eyelid.[9] If there is involvement of the canthal angle, this is angular blepharoconjunctivitis and can be caused by an infection such as Moraxella or, in rare cases, deficiency of vitamin B6.[8][10] If the anterior eyelid is involved, this can point to an infection such as Staphylococcus or a seborrheic process.[11] There is an association between this and acne rosacea.[12] Other causes of blepharoconjunctivitis include parasitic infections such as Demodex, pubic lice, and drugs such as dupilumab.[13][14][15]

Epidemiology

Due to the similarity between blepharoconjunctivitis and blepharitis, it is difficult to separate epidemiological data for the two. Additionally, there is a scarcity of reliable data on the prevalence of blepharitis in the general population. This is largely due to the majority of studies focusing on the population of eye clinics. A US study of ophthalmologists and optometrists found 37% to 47% of patients in their eye clinics exhibited signs of blepharitis.[16] A study of 90 patients at one center found the mean age of their patients to be 50 years old.[17] In a separate study, infective blepharitis (staphylococcal) was more common in females with the age of onset being 42. In seborrheic blepharitis, the mean age was approximately 50, and there was no significant between sexes.[2][18]

Pathophysiology

The pathophysiology of blepharoconjunctivitis is poorly described in the literature and is likely to be multifactorial. As we have discussed, there are many contributing factors, including inflammatory skin conditions, mild longstanding bacterial infections, and parasites.

History and Physical

Sufferers of blepharoconjunctivitis describe a typical blepharitic picture of eye irritation with foreign body sensation and crusting of the eyelids along with reports of red eyes. Symptoms are generally worse in the morning, and patients may report eyelids being stuck shut upon waking. Usually, both eyes are affected, and symptoms can fluctuate.

With regards to signs on examination, the patient will likely exhibit a rapid tear film break up time (<10 seconds) when visualized with fluorescein under blue light, and there may be corneal erosions or ulceration. Inspection of the sclera and conjunctivae will show varying degrees of conjunctival injection.

If the underlying blepharitis is anterior in origin, the eyelid margin will appear edematous. The eyelid margin will be erythematous, and telangiectasia may be seen. There may be crusting on the eyelid margin with the formation of collarettes at the base of the lashes. In chronic cases, there may be changes in the eyelashes themselves, such as poliosis (depigmentation), trichiasis (change in direction), or madarosis (reduction in the number of eyelashes). The eyelid may be distorted, and ectropion or entropion may be visible.

If the underlying blepharitis is posterior in origin, the Meibomian glands will be dilated, and the aperture clogged with a visible 'head' or 'cap' of thick oil. On slit-lamp examination, these 'heads' appear like a string of pearls lying on the eyelid margin. The eyelid immediately surrounding the glands may be scarred or visibly inflamed.

Evaluation

Blepharoconjunctivitis is a clinical diagnosis based upon the history, signs, and symptoms of the patient. Investigations such as tear film break up time can be useful but is not necessary. In cases that are refractory to treatment, one should consider lid biopsy to rule out a malignancy. Examination with fluorescein drops and blue light can be useful to detect corneal erosions or ulcers, which are associated with chronic poorly controlled blepharoconjunctivitis.

Treatment / Management

The mainstay treatment of blepharoconjunctivitis is meticulous lid hygiene. Using a warm eye compress for 5 to 10 minutes helps to soften the oil within the Meibomian glands. Massaging of the lid margin can help express the oil, and an eyelash scrub with a mild shampoo removes debris. Lid hygiene should be encouraged even after an acute exacerbation has subsided due to the chronic nature of the condition. Artificial tears can aid dry eye symptoms, and topical steroids are useful in the acute inflammatory stages of an exacerbation. Topical antibiotics should be offered if lid hygiene alone is insufficient, and this proves to be especially effective if the cause is bacterial such as in a staphylococcal infection.[19] Cases of seborrheic blepharitis often coincide with seborrheic dermatitis. These patients will benefit from concurrent treatment of the underlying dermatitis. In patients suffering from posterior blepharitis, oral azithromycin can prove useful.[20](B2)

Supplementation of omega-3 and omega-6 fatty acids to alleviate dry eye symptoms is a controversial topic. A recent Cochrane systematic review suggested that Omega-3 supplementation may be beneficial but states the quality of evidence is poor.[21](A1)

Differential Diagnosis

In patients who are refractory to treatment, it is important to rule out malignancy, especially if there are lash changes. Malignancy tends to affect the lower lid, and there should be a high index of suspicion if the symptoms are unilateral. Patients with dry eye syndrome may present with a similar 'gritty' foreign body sensation in their eyes. However, they will usually lack the inflammation and crusting on the lid margins.

Prognosis

Prognosis is generally good, and the majority of patients achieve symptomatic relief. Due to the chronic nature of the condition, ongoing meticulous lid hygiene is necessary as maintenance therapy to prevent acute exacerbations.

Complications

Complications can occur in long-term chronic cases. Involvement of the cornea, such as ulceration, scarring, or vascularization, is possible. Additionally, the lid margin can be distorted, leading to trichiasis, ectropion/entropion, or madarosis. Ulceration or perforation requires urgent aggressive therapy to prevent further permanent vision impairment.