Epicanthal folds are vertical or oblique skin folds of the upper eyelid that extend over the inner canthus (medial corner of the eye), partially or completely obscuring it.

• They can make the eyes appear crossed or closer together, as the pupil lies nearer to the inner canthus than the outer canthus.

• Epicanthal folds are normal in infants and young children, particularly among Asian populations.

• They may also occur as a familial trait in other ethnic groups or as an acquired feature with aging.

• Pathologic significance arises when associated with other features, such as oblique palpebral fissures, which in non-Asian children may indicate Down syndrome (trisomy 21).

Pathophysiology

Epicanthal folds result from variations in eyelid and periocular tissue development:

• Normal developmental variation: Folds are present in many infants and resolve with age as facial bones grow.

• Genetic syndromes: In conditions like Down syndrome, Noonan syndrome, or Fetal alcohol syndrome, the folds reflect altered craniofacial development.

• Ethnic variation: Common among Asians, Native Americans, and some African populations, representing normal anatomical diversity.

The fold itself does not impair ocular function but can mask the inner canthus, affecting ocular examination.

Examination Technique

Inspection

• Observe the eyes in primary gaze, noting the presence, height, and direction of the fold.

• Evaluate symmetry between eyes and correlation with other facial features.

Associated Assessment

• In non-Asian children, check for oblique palpebral fissures, flat nasal bridge, and epicanthal fold prominence.

• Consider syndromic assessment if other dysmorphic features are present.

Clinical Features

Differential Diagnosis

Pediatric considerations

• Epicanthal folds are normal in infancy and often regress with facial growth.

• Important in screening for syndromes such as Down syndrome when accompanied by other dysmorphic features.

Geriatric considerations

• Folds may appear later in life due to loss of periorbital fat or eyelid laxity.

• Usually not clinically significant in the elderly.

Limitations

• Presence alone is not diagnostic of any disorder.

• Must evaluate in the context of ethnicity, age, and other facial features.

Patient counseling

• Reassure that epicanthal folds are normal in most children and certain ethnic groups.

• Explain that in non-Asian children with additional facial features, further evaluation may be warranted to rule out syndromes like Down syndrome.

• Emphasize that the fold itself does not affect vision.

Conclusion

Epicanthal folds are skin folds at the inner corner of the eye that can be a normal variant or part of a genetic syndrome. Careful evaluation of associated facial features, ethnic background, and age is essential to distinguish normal developmental variation from pathologic conditions.

References

1. Kliegman RM, et al. Nelson Textbook of Pediatrics. 22nd ed. Philadelphia: Elsevier; 2021.

2. Cohen MM. Craniofacial Anomalies: Epicanthal Folds and Related Features. Am J Med Genet. 1992;44(2):101–108.

3. Bull MJ. Health Supervision for Children With Down Syndrome. Pediatrics. 2011;128(2):393–406.

4. Gorlin RJ, Cohen MM, Hennekam RC. Syndromes of the Head and Neck. 5th ed. New York: Oxford University Press; 2015.