Congenital onychodysplasia of the index fingers is defined by the presence of the condition at birth, either unilateral or bilateral
index finger
The index finger (also referred to as forefinger, first finger, second finger, pointer finger, trigger finger, digitus secundus, digitus II, and many other terms) is the second digit of a human hand. It is located between the thumb and the mid ...
involvement, variable distortion of the nail or
lunula, and
polyonychia
''Polyonychia'' also known as ''supernumerary nails'' is a condition in which two or more nails grow in the same finger or toe.
Signs and symptoms
The signs/symptoms of polyonychia are very easy to detect: two or more nails growing on the sa ...
, micronychia,
anonychia
Anonychia is the absence of fingernails or toenails, an anomaly which may be the result of a congenital ectodermal defect, ichthyosis, severe infection, severe allergic contact dermatitis, self-inflicted trauma, Raynaud phenomenon, lichen planus ...
, hemi-onychogryphosis, or malalignment.
This condition is also called Iso-Kikuchi syndrome, since Iso was the first author who published it in a Japanese paper.
Signs and symptoms
Numerous nail anomalies are noted, such as uneven
lunula, nail malalignment, hemionychogryphosis,
polyonychia
''Polyonychia'' also known as ''supernumerary nails'' is a condition in which two or more nails grow in the same finger or toe.
Signs and symptoms
The signs/symptoms of polyonychia are very easy to detect: two or more nails growing on the sa ...
, micronychia, and
anonychia
Anonychia is the absence of fingernails or toenails, an anomaly which may be the result of a congenital ectodermal defect, ichthyosis, severe infection, severe allergic contact dermatitis, self-inflicted trauma, Raynaud phenomenon, lichen planus ...
.
Causes
It is still unknown what exactly causes congenital onychodystrophy of the index finger. Nonetheless, there is evidence in favor of hereditary transmission.
Diagnosis
Congenital onychodysplasia of the index fingers is diagnosed based on five criteria:
# Congenital occurrence.
# Bilateral or unilateral index finger involvement.
# Variations in nail appearance.
# Potential hereditary involvement.
# Associated bone abnormalities.
See also
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List of cutaneous conditions
Many skin conditions affect the human integumentary system—the organ system covering the entire surface of the body and composed of skin, hair, nails, and related muscle and glands. The major function of this system is as a barrier against t ...
References
Further reading
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External links
VisualDx
{{Disorders of skin appendages
Conditions of the skin appendages