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Demodex is a lid commensal that can cause ocular surface inflammation, blepharitis and blepharokeratoconjunctivitis.1 Demodex folliculorum and Demodex brevis are the most common species causing anterior and posterior blepharitis, respectively.2 We report varied clinical presentations of ocular demodicosis encountered in a rural population. In all patients, eyelash samples were examined under the microscope after preparation with glycerol/10% potassium hydroxide. On detection of Demodex mites, patients were treated with lid scrubs and application of diluted (50%) tea tree oil over the lid margins.
Case 1: A woman in her 60s presented with complaints of bilateral ocular irritation and itching for 1 month. On examination, she had prominent greasy scaling at the eyelash roots. No corneal involvement was noted. Eyelash samples revealed Demodex mites (figure 1A–C). Symptoms and signs resolved after 1 month of medical management.
Case 2: A teen-aged boy presented with bilateral scaling and cylindrical dandruff around lashes and conjunctival congestion for 1 week. Demodex (figure 1D–H) was detected and he was started on anti-Demodex management.
Case 3: A woman in her 20s presented with ocular irritation and examination showed scaling of eyelashes with cylindrical dandruff, bilateral superficial punctate keratitis and inferonasal pannus over the cornea. No other abnormalities were noted. She was initially treated for seborrhoeic blepharitis alone. Since no improvement was noted, lash samples were taken and revealed Demodex mites (figure 2A–F). Symptomatic improvement was noted within 2 weeks of starting therapy.
Case 4: A man in his 20s showed a ‘V’ shaped corneal infiltrate near limbus in his left eye and bilateral scaling of eyelashes. No organisms were noted on smear in the corneal scrape samples. There was no symptomatic improvement with topical antibacterial treatment (0.5% moxifloxacin eye drops 2 hourly) alone. Later, Demodex mites were isolated from eyelashes and on combined topical antibacterials for left eye and demodicosis management for both eyes, both the corneal infiltrates and blepharitis resolved (figure 2G–H).
Case 5: A woman in her 50s presented with complaints of ocular irritation for 1 week. Examination showed spheroidal degeneration in right cornea, pseudophakic left eye and severe scaling of eyelashes with cylindrical dandruff. After detection of several live Demodex mites from her eyelashes, targeted management was initiated and blepharitis completely resolved (figure 3A–F).
With the example of all these cases, we believe that Demodex can present with varied lid and corneal manifestations. Though not prevalent in any of our cases, ocular demodicosis is a known risk factor for chalazion in all ages.3 A simple microscopic examination of eyelash samples can help us diagnose and thereafter provide specific treatment. Tea tree oil (TTO-terpinen-4-ol)— with concentrations ranging from 5% twice a day to 50% weekly—is highly effective in its treatment followed by medications like metronidazole, ivermectin and permethrin.4 TTO application should be supplemented with warm saline compression and lid scrubs.5 Our cases presented after other therapeutic modalities were tried elsewhere, and we could achieve rapid resolution of the condition once the diagnosis was established.
Demodex can present as blepharokeratoconjunctivitis with a spectrum of findings and can be easily missed which leads to several recurrences. It is thus important to suspect, diagnose and subsequently direct the treatment towards the eradication of the mites.
Eyelashes with cylindrical dandruff are pathognomonic for ocular Demodex infestation and tea tree oil application is effective for management of this condition.
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Contributors All persons designated as authors qualify for authorship, and all those who qualify are listed. Each author has participated sufficiently in the work to take public responsibility for appropriate portions of the content. PV collected the data, conceptualised and drafted the manuscript. SIM edited the manuscript. SS, BB and SIM finalised the article. SS and BB were involved in the management of the patients and contributed to the interpretation of the results.
Funding This study was funded by Hyderabad Eye Research Foundation (LEC-BHR-R-08-22-928).
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.