Etty Bitton, BSc, OD, MSc is an Associate Professor and Director of the Dry Eye Clinic at the Université de Montréal. Her research interests include tear film evaluation, dry eye and its effects on contact lens wear.
Download the poster (.pdf), which was originally shared at the British Contact Lens Association (BCLA) Clinical Conference and Exhibition, 2014.
A CASE OF MISTAKEN BLEPHARITIS IDENTITY: STAPH OR DEMODEX?
Etty Bitton OD, MSc, FAAO, FBCLA, Samantha Kronish
Universite de Montreal, Montreal, Quebec, Canada
Purpose: Anterior blepharitis is usually caused by a staphylococcus aureus (SA) infection, and expressed clinically as “crusty debris” on inflamed lid margins. Conventional therapy includes antibiotics to reduce the bio-burden. When patients are unresponsive to treatment, one must look at other potential causes. A meticulous observation of the type of debris and its placement on the eyelash may give us a clue. SA-blepharitis has golden yellow crusting at the base of the lash which progresses along the lash when it grows. Demodex, on the other hand, is a parasite, giving rise to gelatinous debris, which surrounds the base of the lash, described as a dandruff cuff (DC). The Demodex mites are light sensitive so their heads are buried in the lash follicle with only their tails visible at the eyelash base. Their small size makes them difficult to identify with a biomicroscope, hence only epilation of lashes with DC and observation under a micros cope confirms the diagnosis. The true prevalence of Demodex is unknown but is reported to be abundant in the elderly.
This report describes 3 cases presenting with dry eye (DE) symptoms including discomfort and mild itching, which at first was mistaken for SA-blepharitis and turned out to be Demodex infestation. The case provides an overview of the Demodex mite, its clinical presentation and examination technique and tea tree oil-based treatment options. It has been reported that Demodex may be more common than we think and clinicians should consider it in their differential diagnosis of any ocular discomfort.
