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Other Resources UpToDate PubMed


Contributors: Claire Marie Reyes-Habito MD, Mario Lacouture MD, Lowell A. Goldsmith MD, MPH
Other Resources UpToDate PubMed


Trichomegaly is a condition where there is an increase in the length and thickness of eyelash hair. It can be congenital, acquired, or drug induced.

Elongated and thicker eyelashes are frequently present in children with rare congenital syndromes such as Oliver-McFarlane syndrome and Cornelia de Lange syndrome.

Acquired disorders such as human immunodeficiency virus (HIV) infection, atopic dermatitis, allergic rhinitis, uveitis, and vernal keratoconjunctivitis may also be associated with trichomegaly.

Drugs that are commonly associated with eyelash growth are prostaglandin analogs, epidermal growth factor receptor inhibitors (EGFRIs), and MEK inhibitors, and less commonly interferon-alpha and cyclosporine.


L67.9 – Hair color and hair shaft abnormality, unspecified

279425004 – Disorder of hair

Look For

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Diagnostic Pearls

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Differential Diagnosis & Pitfalls

  • Oliver-McFarlane syndrome – Congenital disorder associated with dwarfism, intellectual disability, and retina pigmentary degeneration.
  • Cornelia de Lange syndrome – Congenital disorder associated with short stature; specific facial features; and cardiac, neurologic, gastrointestinal, and musculoskeletal malformations.
  • HIV-infection-associated trichomegaly – Long and silky eyelashes (see HIV disease).
  • Atopic-associated trichomegaly – Long and silky eyelashes (see atopic dermatitis).
  • EGFRI and MEK inhibitor-associated trichomegaly – Coarse, curled, tortuous eyelashes.
  • Prostaglandin analog-induced trichomegaly

Best Tests

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Management Pearls

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Drug Reaction Data

Below is a list of drugs with literature evidence indicating an adverse association with this diagnosis. The list is continually updated through ongoing research and new medication approvals. Click on Citations to sort by number of citations or click on Medication to sort the medications alphabetically.

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Last Updated:02/16/2020
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A medical illustration showing key findings of Trichomegaly : Trichomegaly
Clinical image of Trichomegaly - imageId=2204124. Click to open in gallery.  caption: 'Elongated eyelashes in a patient infected with HIV.'
Elongated eyelashes in a patient infected with HIV.
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