[Ethyl ether: an old ally against oral ivermectin-resistant Demodex blepharitis].

Demodex folliculorum is a mite which is a parasite of the hair follicles, sebaceous glands and eyelashes. Its incidence in humans increases with age. Infestation by this parasite involves chronic blepharitis with periods of exacerbation and is frequently underdiagnosed in clinical practice.1 We present the case of a male patient, 53-year-old, who visited due to bilateral eczematous anterior blepharitis resistant to conventional topical treatments (daily palpebral cleaning with sterile towels (Estila®) and carbomere lubricating cream). Upon exploration, the patient exhibited crusty aggregates and “pearly” remains forming a collar around hair follicles. Palpebral edges appeared thickened and erythematous (Fig. 1). Direct microbiological analysis of the eyelashes (40×, 100×, obtained with sterilized tweezers, one of each right and left upper eyelid and placed in a carrier plate over a drop of physiological solution) confirmed the existence of the live parasite. The patient was treated with oral ivermectin, 6 mg twice a day for 1 day, repeating the same regime 14 days later while maintaining the initial topical treatment.2 Ninety days after beginning the treatment no improvement in symptoms was observed and microbiological analysis (100×, 40×) confirmed the persistence of the mites. After the failure of the initial therapy a daily treatment was initiated, consisting in the application of topical anesthetic prior to massaging the palpebral edge in both eyes with a cotton swab dipped in ether (99.9% ethyl ether, 0.02% water, density 0.713 g/ml. Contacto Guinama S.L.U Alboraya, Valencia, Spain) for at least 10 min. Local adverse effects during the treatment were not observed. Two weeks later, the palpebral crusty lesions disappeared completely and the initial symptoms (itching, foreign body feeling) improved significantly (Fig. 2). The microbiological analysis of the