Chronic inflammation of the eyelid margin — anterior (Staph/seborrheic) or posterior (meibomian gland dysfunction).
Also known as: blepharitis, anterior blepharitis, posterior blepharitis, meibomian gland dysfunction, MGD
Overview
Chronic inflammation of the eyelid margins. Anterior blepharitis affects the base of the lashes and is staphylococcal or seborrheic. Posterior blepharitis affects the meibomian gland orifices — meibomian gland dysfunction (MGD) — and is the most common form, frequently associated with ocular rosacea.
Epidemiology
Among the most common ocular complaints in primary care and ophthalmology. Prevalence increases with age; coexists with dry eye disease, rosacea, seborrheic dermatitis, and atopic dermatitis.
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Question 1EENTMedium
A 58-year-old man presents with several months of burning, itching, and a gritty foreign-body sensation in both eyes that is worst on awakening. He reports crusting along the lash margins each morning and occasional blurry vision that clears with blinking. He wears no contact lenses and has a history of rosacea. On slit-lamp examination, the eyelid margins are erythematous and thickened with greasy scales and collarettes around the lash bases; the meibomian gland orifices appear plugged. Conjunctivae are mildly injected and visual acuity is 20/25 bilaterally. Which of the following is the most likely diagnosis?
AAllergic conjunctivitis
BChalazion
CBacterial conjunctivitis
DBlepharitis
EHordeolum
Reveal answer & full explanation
Correct answer: D — Blepharitis
AAllergic conjunctivitis
BChalazion
CBacterial conjunctivitis
DBlepharitis✓
EHordeolum
Why Blepharitis is correct
Blepharitis is inflammation of the eyelid margins; this patient's rosacea history is a major risk factor for posterior/meibomian blepharitis.
Classic findings present here: erythematous thickened lid margins, greasy scales and collarettes at the lash bases, plugged meibomian gland orifices, and morning crusting with foreign-body sensation.
Mechanism: bacterial colonization (often Staphylococcus), meibomian gland dysfunction, and Demodex contribute to chronic margin inflammation and tear film instability.
Why the others are wrong
Bacterial conjunctivitis — presents acutely with copious purulent discharge and diffuse bulbar conjunctival injection rather than chronic lid margin disease with collarettes.
Allergic conjunctivitis — features prominent itching with watery discharge, chemosis, and papillae, typically in atopic patients, without lid margin scaling or plugged meibomian glands.
Hordeolum — a focal, tender, localized lid nodule from an acutely infected gland, not the diffuse bilateral margin involvement seen here.
Chalazion — also stems from meibomian gland obstruction and is common in rosacea, but it presents as a focal, painless, firm nodule within the lid from a single blocked gland, not diffuse bilateral lid margin inflammation with greasy scales and collarettes.
Question 2EENTMedium
A 58-year-old man presents with chronic redness, itching, and burning along both eyelid margins for several months. He reports crusting of his lashes upon waking and a gritty foreign-body sensation throughout the day. He has a history of rosacea and seborrheic dermatitis of the scalp. Slit-lamp examination shows greasy scales at the base of the lashes, thickened lid margins, and inspissated meibomian gland orifices. Gentle pressure on the lower lids expresses thick, turbid meibomian secretions. Which of the following is the most likely complication of this condition?
AEvaporative dry eye from tear film instability
BSebaceous carcinoma from chronic meibomian inflammation
CPreseptal cellulitis from lid-margin bacteria
DAqueous-deficient dry eye from lacrimal hypofunction
ENeurotrophic keratopathy from corneal nerve loss
Reveal answer & full explanation
Correct answer: A — Evaporative dry eye from tear film instability
AEvaporative dry eye from tear film instability✓
BSebaceous carcinoma from chronic meibomian inflammation
CPreseptal cellulitis from lid-margin bacteria
DAqueous-deficient dry eye from lacrimal hypofunction
ENeurotrophic keratopathy from corneal nerve loss
Why Evaporative dry eye from tear film instability is correct
This patient has chronic posterior blepharitis with meibomian gland dysfunction: lid margin inflammation, inspissated meibomian gland orifices, association with rosacea and seborrheic dermatitis
Meibomian glands secrete the lipid layer of the tear film that prevents aqueous evaporation
When these glands are obstructed and inflamed, lipid secretion is deficient or altered, leading to rapid tear film evaporation and evaporative dry eye disease — the most common complication, recognized clinically by a reduced tear breakup time
Other recognized sequelae include recurrent hordeola, chalazia, trichiasis, and corneal punctate epitheliopathy
Why the others are wrong
Preseptal cellulitis from lid-margin bacteria — an acute bacterial infection of the eyelid anterior to the orbital septum that can rarely follow an infected hordeolum; it presents as a tender, swollen, erythematous lid and is an uncommon event, not the expected consequence of chronic meibomian gland dysfunction
Aqueous-deficient dry eye from lacrimal hypofunction — results from reduced tear production by the lacrimal gland (e.g., Sjogren syndrome, aging, anticholinergic drugs), typically with a low Schirmer test; blepharitis with thick, turbid expressed meibum depletes the lipid layer of the tear film, not the aqueous layer
Neurotrophic keratopathy from corneal nerve loss — results from loss of corneal sensory innervation (CN V1) after herpes simplex or zoster keratitis, diabetes, or trigeminal nerve injury, leaving a reduced or absent corneal sensation; blepharitis does not abolish corneal sensation, and its corneal complications are punctate epitheliopathy and marginal keratitis
Sebaceous carcinoma from chronic meibomian inflammation — sebaceous carcinoma most often arises from the meibomian glands and classically masquerades as chronic blepharitis or a recurrent chalazion, but it is a rare malignancy that mimics this condition rather than complicating it; chronic bilateral meibomian gland dysfunction is not a recognized precursor, and unilateral or treatment-refractory lid-margin inflammation is what should raise suspicion for it and prompt biopsy
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Anterior blepharitis: bacterial colonization (mostly S. aureus) and seborrheic scaling of the lash follicles lead to inflammation. Posterior blepharitis/MGD: meibomian gland orifices become obstructed by abnormally viscous secretions, lipase-producing bacteria alter tear film lipid layer, and chronic inflammation results in evaporative dry eye. Demodex folliculorum/brevis mites can contribute via mechanical and inflammatory effects with characteristic cylindrical lash dandruff.
Clinical presentation
Symptoms
Chronic burning, itching, foreign body sensation
Crusting and stickiness of eyelids on awakening
Eye redness, tearing or paradoxical dryness
Recurrent styes or chalazia
Photophobia and intermittent blurred vision (tear film instability)
Often bilateral, waxing and waning
Signs / physical exam
Anterior: scaling and collarettes at base of lashes; lash loss (madarosis), misdirected lashes (trichiasis); eyelid margin erythema
Posterior/MGD: capped or plugged meibomian gland orifices, frothy tear film, telangiectasias along posterior lid margin, thickened lid margin
Demodex: cylindrical 'sleeves' of waxy material at lash base
Punctate epithelial erosions on cornea with rapid tear break-up
Concurrent rosacea findings on face: malar erythema, telangiectasias, rhinophyma
Classic findings
Anterior collarettes vs capped meibomian glands with frothy tears — often coexist.
Differential diagnosis
Dry eye disease (aqueous deficient) — Burning, foreign body sensation, often coexists with MGD; Schirmer test, tear break-up time
Eyelid massage and expression of meibomian glands after warming
Lid hygiene with dilute baby shampoo, commercial lid scrub pads, or hypochlorous acid spray
Artificial tears (preservative-free) for tear film support
Treat coexisting dry eye and rosacea
Second-line / adjunct
Topical ocular antibiotic for anterior blepharitis — erythromycin ointment, bacitracin ointment, or azithromycin 1% drops — applied to lid margin nightly for 2-8 weeks
Topical corticosteroid (short course) — loteprednol 0.5% or fluorometholone drops — for inflammatory flares or marginal keratitis; monitor IOP
Oral tetracycline-class for posterior blepharitis/MGD or ocular rosacea — doxycycline 50-100 mg BID, minocycline 50-100 mg daily, or tetracycline 250 mg QID — 6-12 weeks then taper; avoid in pregnancy/children <8
Topical cyclosporine 0.05% BID or lifitegrast 5% BID for associated dry eye
Demodex blepharitis: lotilaner 0.25% ophthalmic solution 1 drop BID for 6 weeks (FDA-approved 2023); tea tree oil or 4-terpineol (e.g., Cliradex) lid scrubs are alternatives
In-office thermal pulsation (LipiFlow) or intense pulsed light for refractory MGD
Treat coexisting rosacea with topical metronidazole, ivermectin, or oral therapy
Complications
Chronic dry eye disease and tear film dysfunction
Recurrent hordeola and chalazia
Conjunctivitis and marginal keratitis (corneal infiltrates from staphylococcal hypersensitivity)
Corneal neovascularization, scarring, ulceration in severe disease
Contact lens intolerance
Trichiasis and madarosis
PANCE pearls
Blepharitis is chronic — patients must understand it is managed, not cured. Adherence to daily lid hygiene is everything.
Posterior blepharitis (MGD) is the most common form and the leading cause of evaporative dry eye.
Oral doxycycline works in MGD through its anti-inflammatory and anti-lipase effects, not antibacterial activity — dose lower than for infection.
Cylindrical dandruff at the lash base = Demodex — treat with lotilaner 0.25% drops (FDA-approved 2023) or tea tree oil-based lid scrubs.
Marginal corneal infiltrates with a clear corneal interval at the limbus are immune-mediated reactions to staphylococcal antigen — treat the lids and add topical steroid.
Unilateral 'blepharitis' that does not respond to standard therapy in an older patient — think sebaceous gland carcinoma and refer for biopsy.
References
AAO 2018 — American Academy of Ophthalmology. Blepharitis Preferred Practice Pattern. Ophthalmology 2019;126(1):P56-P93
TFOS DEWS III — Jones L, Craig JP, Markoulli M, et al. TFOS DEWS III: Management and Therapy. Am J Ophthalmol 2025;279:289-386
Cochrane 2012 — Lindsley K et al. Interventions for chronic blepharitis. Cochrane Database Syst Rev 2012;5:CD005556
Educational use only. This outline is a study aid for PA students and is not medical advice or a substitute for clinical judgment. FirstPassPA is an independent study tool and is not affiliated with, endorsed by, or sponsored by NCCPA or PAEA. PANCE® and PANRE® are registered trademarks of the National Commission on Certification of Physician Assistants; End of Rotation™ is a program of the Physician Assistant Education Association.