Evaluating Efficacy of Permethrin Cream for Demodex Blepharitis

Blepharitis is an inflammation of the eyelids. Demodex blepharitis is specific to infections caused by the parasites Demodex folliculorum or Demodex brevis that inhabit both hair follicles and sebaceous glands. These parasites are commonly found on the skin of older adults and less commonly, young children.^1-4

Health care professionals must be aware of current treatment recommendations as well as potential treatments that are effective against certain conditions.

Infected individuals can present either with symptoms or asymptomatically. Symptoms include itching, redness, burning, and level of tearing.¹

Common treatments for Demodex blepharitis include single dose ivermectin, taken twice with each dose 2 weeks apart, metronidazole treatment for 10 days, and topical tea tree oil.¹ However, according to the results of recent studies, all of these treatments may be ineffective for Demodex blepharitis. Patients who received ivermectin and tea tree oil only experienced a 6% rate of mite eradication.¹

Researchers have been looking into permethrin as potential treatment of Demodex blepharitis.^1,3 Permethrin, an insecticide of the pyrethroid family, is used against mites, ticks, and other insects.^1,3

A recent study evaluated 21 patients with this condition over a 6-month period—treatment of this condition takes months.¹ The researchers determined the efficacy of permethrin 5% cream being applied to each patients’ eyelashes for 6 months. Of significance, researchers noticed an improvement in parasite burden and blepharitis symptoms.

Published in the journal Clinical Science, the study lacked a decrease in ocular surface disease index (OSDI) score, which is used to estimate patients’ experiences of ocular irritation and dry eye. This may have been due to permethrin not being able to penetrate to the location of the ectoparasite Demodex brevis, which tends to migrate deep within the sebaceous glands.

Permethrin is usually only effective against Demodex folliculorum, which is found mostly in the eyelash follicle.

References

• Hecht I, Melzer-Golik A, Sadi Szyper N, Kaiserman I. Permethrin cream for the treatment of demodex blepharitis. Cornea. 2019 Jun 3. doi:10.1097/ICO.0000000000002013. [Epub ahead of print]
• Damian D, Rogers M. Demodex infestation in a child with leukemia: treatment with ivermectin and permethrin. Int J Dermatol. 2003;42(9):724-726.
• Hirsch-Hoffmann S, Kaufmann C, Bänninger PB, Thiel MA. Treatment options for demodex blepharitis: patient choice and efficacy. Klin Monbl Augenheilkd. 2015;232(4):384-387.
• Kabataş N, Doğan AŞ, Kabataş EU, et al. The Effect of demodex infestation on blepharitis and the ocular symptoms. Eye Contact Lens. 201743(1):64-67.