Distichiasis is a condition of the eyelashes wherein the lashes or hairs are associated with and arise from the meibomian orifices. It can be congenital or acquired. Chronic inflammatory diseases of the eyelids and/or the conjunctiva are the major etiologic reason for the acquired form. This includes chronic cicatricial pemphigoid, erythema multiform, chemical injury, trachoma, chronic blepharitis, and chronic allergies. The acquired form is more likely to involve the lower eyelids. The congenital form is dominantly inherited with complete penetrance. The congenital form may be an isolated finding or associated with ptosis, strabismus, congenital heart defects, or mandibulofacial dysostosis. Pain, tearing, photophobia, foreign body feeling, and blurry vision are all possible symptoms associated with distichiasis.
ICD10CM: H02.89 – Other specified disorders of eyelid Q10.3 – Other congenital malformations of eyelid
SNOMEDCT: 95339000 – Distichiasis
Differential Diagnosis & Pitfalls
The key finding of hairs growing from the meibomian gland orifices versus those coming from the normal hair-bearing areas of the eyelid marks the difference from .
Distichiasis can be hereditary with autosomal dominant inheritance; the trait is also associated with multiple syndromes including syndromes with peripheral lymphedema. For a complete list of syndromes, search Distichiasis in the Online Mendelian Inheritance in Man (OMIM) database: https://www.ncbi.nlm.nih.gov/omim.