Demodex Infestation Quiz for Healthcare

Blepharitis

• Blepharitis is inflammation of the eyelids.
• Anterior blepharitis affects the eyelashes and follicles.
• Staphylococcal blepharitis is caused by Staphylococcus epidermidis.
• Seborrheic blepharitis is a disorder of sebaceous gland function potentially linked to dandruff.
• Posterior blepharitis involves Meibomian glands.
• Angular blepharitis typically affects the lateral canthi.
• Possible organisms linked with angular blepharitis are: Moraxella lacunata and Staphylococcus aureus or epidermis.
• Demodex mites infesting the follicles are found in 50% of blepharitis cases.
• Demodex mites are observed in 100% of patients over 70-years of age.
• Blepharitis can be acute or chronic.

Primary vs Secondary Blepharitis

• Primary blepharitis includes rosacea, seborrhea, and hypersensitivity caused by staphylococcal toxins.
• Secondary blepharitis is a result of another disease entity (ex: infections, infestations, trauma, allergies)
• Infectious processes including bacterial (virus vs.) cause secondary blepharitis.

Acute vs Chronic Blepharitis

• Acute: Causes include infections, infestations, trauma, toxicity, and acute allergies.  Signs/symptoms: hyperemia, edema, telangiectasia, flaking, debris, discharge, foreign body sensation, and pain.. 
• Chronic: Causes include poor hygiene, seasonal/perennial allergies, ocular rosacea, and makeup overuse. Signs/symptoms: lash involvement, ulceration, hordeolum (stye), and dry eye.

Staphylococcal Blepharitis

• Etiology: Infection of lash follicles & lid margins with Staph.
• Staphylococcus epidermidis is more common.
• Staphylococcus aureus is less common, normally not present in the lids

Inflammatory Response

• Mechanism: Bacteria produce lipase.
• May alter tear lipid spectrum; cause increased free fatty acids irritants to the eyelids.
• May induce inflammation and hyperkeratinization of Meibomian orifices.
• Effect: blood vessels dilate (redness), increased vascular permeability (edema), and movement of neutrophils (PMNs) from blood into tissues.

Symptoms

• Variable depending on severity and damage to tissue.
• Variable depending on time of day.
• Worse upon awakening.
• Foreign body sensitivity, grittiness, stinging, burning, and irritation.
• Possible pain, tender lids, and itching.
• Dry eye symptoms.

Clinical Signs

• Crusts (flakes) start at the base of the lash. They look similar "impaled cornflakes" indicative of staph exotoxin activity.

Grading Scales

• Efron Grading Scale: Used for evaluating blepharitis (trace-4+).
• Always grade findings when applicable, allowing you to see if the condition is improving/progressing.
• Trace is very early signs
• 4+ is the most severe

Lids

• Erythema: Diffuse redness along the lid margin.
• Edema: Puffiness resulting from fluid accumulation; tender to palpation.

Lids (cont'd)

• Lid neovascularization: Glomerular fronds of vessels at margins; deeper vessels causing pink "cast".
• Tylosis: Thickening of the eyelid tissue.
• Indurated: Hardened.

Collarettes

• Cylindrical tubes of material that go up the eyelash base.
• Sleeves start at last base
• Collarettes go higher up the eyelash base

Eyelashes

• Exotoxins damage follicles and cause structural changes.
• Madarosis: Loss of lashes.
• Poliosis: Whitening of eye lashes.
• Trichiasis: Misdirected lashes

Secondary Conditions

• Blepharoconjunctivitis: Secondary conjunctival infection.
• Punctate Epithelial Erosion (PEE): Pooling of exotoxins in the tear lake; inferior 1/3 of the cornea.

Clinical Pearl (PEE)

• PEE = epithelial cell loss in cornea, small divots in the cornea
• Stains with fluorescein (enhanced viewing with cobalt (blue) filter).
• Pattern indicates possible etiology.
• High association with ocular surface dryness.

Treatment

Lid Hygiene

• Warm Compresses: Soften and loosen crusts, improve blood flow (10-15 mins/time bid to qid).
• Lid Scrubs: Primary treatment for blepharitis; scrub lid margins to remove debris (bid to qid). Can use lid wipes, foam cleansers; often manage most mild cases.
• Diluted baby shampoo (not recommended anymore).

Antibiotics

• Ointments preferred over drops for lid disease.
• Moderate: qhs or bid; Severe: tid or qid.
• Remove crusts before applying.
• Avoid direct application to the eye from tube (prevent contamination & quantity issues).
• Bacitracin: Cell wall inhibitor, excellent against staph, little hypersensitivity.
• Polymyxin B, Neomycin, Erythromycin: vary in efficacy against bacteria
• Gentamicin: Aminoglycoside, very effective against staph.
• Tobramycin: Aminoglycoside, very good against staph.

Oral Ab

• Usually, not the first choice of treatment.
• Consider when severe; patient unable to comply with ointment and lid hygiene.
• Patient has systemic illness.
• Doxycycline (100 mg PO bid x 7-10 days): Inhibits lipase synthesis; inhibits cytokines and chemokines.
• Helpful even if bacteria are resistant to the antibiotic

Steroids

• Consider in moderate-severe immune processes.
• Significant erythema, pain, and tenderness.
• Lid inflammation is responsive to steroids.
• Combination therapy (Ab+Steroid).
• Examples include Tobradex and Maxitrol.
• Steroid use requires monitoring for complications (increased IOP, PSC (posterior subcapsular cataract)).

Clinical Pearl (Steroids)

• Always monitor IOP with steroid use.
• Complications include increased IOP (intraocular pressure) and PSC (posterior subcapsular cataracts).
• Usually takes 2-3 weeks to see IOP effects and may not observe at 1 week follow up.

BlephEx

• Medical-grade disposable micro-sponge used to remove scurf/debris from eyelids & lashes.
• Treatment procedures routinely include proparacaine for numb the eye area.
• Eyes rinsed afterwards.
• 6-8 minute procedure.

Follow-up

• 1-3 weeks depending on severity and prescribed medications.
• Consider follow-up 2-3 weeks later, or within days of cornea involvement.
• Lifetime condition requiring lifetime treatment and management.
• Emphasis on routine lid hygiene.
• Patient return to office for flare-ups.

Associated Conditions

• Marginal Corneal Infiltrate: Hypersensitivity to staph toxins; inflammatory response instead of direct infection: white blood cells infiltrate between epithelium and stroma.
• Phlyctenule: Type IV hypersensitivity to staph toxins; causes elevated white lesions (conjunctiva, limbus, cornea); vasculature may be present.
• Possible associations with tuberculosis

Seborrheic Blepharitis

• Seborrhea is a disorder of sebaceous gland function (unknown etiology); characterized by excess oil production and retention.
• Often associated with seborrheic dermatitis. (e.g., dandruff is hallmark).
• Also associated with rosacea and acne juvenilis.

Signs/Symptoms (Seborrheic Blepharitis)

• Greasy scales: foamy-looking, irregularly shaped, at bases of lashes or spiraling around lashes.
• Scurf: "dandruff-like scales."
• Symptoms often depend on other concurrent processes.
• Scurf frequently asymptomatic.
• Complaint of "mattering" in the morning.

Tx & Pt. Ed. (Seborrheic Blepharitis)

• Tx/Pt.ed.- Lid hygiene, lubricants, treat associated conditions, and follow-up 2-4 weeks, including education on chronic nature and need for daily lid hygiene

Considerations (Blepharitis)

• Primary: Rule out staph involvement; may have mixed blepharitis with staph infection.
• Secondary: Rule out dermatoses; examine other areas. Consider dermatology consult.
• Tertiary: Rule out meibomian gland dysfunction; may have meibomian seborrheic blepharitis

Angular Blepharitis

• Localized eczematoid inflammation at the lateral canthi (corners of the eye).
• Two causative organisms: Moraxella lacunata and Staphylococcus.
• Commonly Staphylococcus aureus or epidermis are more common

Signs/Symptoms (Angular Blepharitis)

• Moraxella: Wet.
• Staph: Dry & scaly, skin repeatedly drying out/scaling/cracking open, chronic lid irritation, and possible itching.

Tx & Pt. Ed. (Angular Blepharitis)

• Antibiotics (e.g., sulfacetamide, neomycin, erythromycin, polymyxin B, and bacitracin).
• Polysporin is good for both moraxella and staph
• Zinc sulfate (0.25%): astringent action; reduces maceration.
• Vasoclear, Clear Eyes, Visine A.C. or Zincfran drops
• Culture & sensitivity if ineffective
• Compliance with treatment to know efficacy.

Demodex

• Mite infestation in follicles, primarily the facial area.
• Demodex folliculorum: infects hair and eyelash follicles.
• Demodex brevis: infects sebaceous and Meibomian glands.
• Observed in 100% of patients older than 70-years of age.
• Mites are likely associated to 50% of blepharitis cases.
• Feed on epithelial cells of eyelid.
• Females lay eggs in follicles; life span 14 days

Signs/Symptoms (Demodex)

• Brittle, easily broken lashes, fall out spontaneously. Pyramidal follicles from edema, mites, and eggs.
• Collarette = highly diagnostic for demodex (e.g., D. brevis blocks meibomian glands & causes MGD).
• Itching, burning, corneal irritation, and heavy eyelids.
• Symptoms worse at night or dim lighting (mites recess into follicles with light).
• Irritation worse in warm weather.

Demodex (cont'd)

• Demodex can carry bacteria on its surface (e.g., Strep and Staph).
• Increased symptoms in rosacea patients.
• Debris & waste may elicit host inflammatory responses (delayed hypersensitivity or an innate immune response)

Diagnosis

• Clinical History: High index of suspicion for blepharitis, conjunctivitis, keratitis or blepharoconjunctivitis in adult patients who have recurrent issues that are refractory to conventional treatments.
• Associated findings: Madarosis, recurrent trichiasis, collarettes and pyramidal elevation of follicles.
• Slit-lamp examination: Look for collarettes and pyramidal elevations.
• Microscopic confirmation: Detection and counting of Demodex eggs, larvae, and adult mites in epilated eyelashes.

Treatment (Demodex)

• Resistant to 75% alcohol, 10% povidone-iodine, and antimicrobials (such as erythromycin and metronidazole).
• Tea Tree Oil (50%): Highly effective against infestation.
• Terpinen-4-ol (T4O): More potent.
• Cliradex, Ocusoft (Oust Demodex).
• Daily cleaning with lid wipes or foam cleansers.
• Treat associated conditions.

Xedmvy

• XDEMVY (lotilaner ophthalmic solution, 0.25%) is FDA-approved for Demodex (primarily Tarsus).
• Treatment is typically 6 weeks
• Possible mechanism of action: Lipophilic agent, targeting mite GABA channels.
• Possible resolution seen: Improved success rates with reductions observed in number of collarettes (Saturn-1, Saturn-2 trials)

Patient Education

• Stress lid hygiene.
• Assure patient normal flora and common.
• Takes 3-4 weeks for response.
• Consider follow-up 4-6 weeks.

Questions?

Test your knowledge on Demodex infestation and its management. This quiz covers the significance of slit-lamp examinations, FDA-approved treatments, and key patient management strategies. Explore common clinical signs and antimicrobial resistance related to Demodex.