Demodex mites cause nearly half of the blepharitis cases in the US1

Demodex Blepharitis

In the United States, Demodex mites cause approximately 45% of blepharitis cases, a common ocular condition characterized by inflammation of the eyelid and affecting up to 20 million Americans.1-4

Population Epidemiology(based on 20M in US with blepharitis)

There are approximately 9 million patients without an FDA-approved therapy.1-4

We believe the number of patients with Demodex blepharitis may be even higher than what's been previously reported.

Published literature shows that at least 45 million people visit eye care clinics annually. Our internal research has shown that 58% of patients presenting at eye care offices have collarettes, a pathognomonic sign of Demodex infestation.5-6

We believe that the prevalence of Demodex blepharitis in the United States may be as high as ~25 million.5-6

Learn how Demodex mites cause disease

Demodex blepharitis is caused by infestation of Demodex mites, the most common ectoparasite found on humans. There are two species of Demodexfolliculorum and brevis—that live on the skin of the face and eyelids.


Demodex brevis

Collarettes are a pathognomonic sign of Demodex blepharitis

Published literature has confirmed the pathognomonic relationship between collarettes and Demodex blepharitis. In a study conducted by Gao et al.,100% of patients with at least one collarette had Demodex blepharitis.7

% of Subjects with Demodex7
Adapted from Gao et al. (2005): High Prevalence of Demodex in Eyelashes with Cylindrical Dandruff. Invst Ophth and Vis Sci, September 2005, Vol. 46, No. 3089-3094.
Demodex blepharitis can be hiding in plain sight

Confirming the presence of collarettes during slit lamp examination is most easily accomplished when the patient looks down.

Slit lamp evaluation, 1.0 mag
Patient looking straight on.
Patient looking straight on with lid lift.
Slit lamp evaluation, 1.0 mag
Patient looking down, diffuse collarettes.

1. Data on file. Tarsus Pharmaceuticals, Inc. 2019. 2. Howden LM, Meyer JA. Age and Sex Composition: 2010. United States Census Bureau, Department of Commerce, Economics and Statistics Administration. 2011. 3. Paulsen AJ, Cruickshanks KJ, Fischer ME, et al. Dry Eye in the Beaver Dam Offspring Study: Prevalence, Risk Factors, and Health-Related Quality of Life. Am J Ophthalmol. 2014;157(4):799–806. 4. Schaumberg DA, Nichols JJ, Papas EB, Tong L, Uchino M, Nichols KK. The International Workshop on Meibomian Gland Dysfunction: Report of the Subcommittee on the Epidemiology of, and Associated Risk Factors for, MGD. Investig. Ophthalmol. Vis. Sci. 2011;52(4):1994–2005. 5. Wilson FA, Stimpson JP, Wang Y. Inconsistencies Exist in National Estimates of EyeCare Services Utilization in the United States. J. Ophthalmol. 2015; 2015:435606. doi: 10.1155/2015/435606. Accessed 01/25/2020. 6. Data on file. Tarsus Pharmaceuticals, Inc. 2020. 7. Gao Y, Di Pascuale MA, Li W, et al. High Prevalence of Demodex in Eyelashes with Cylindrical Dandruff. Investig. Ophthalmol. Vis. Sci. 2005;46(9):3089–3094.

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