HISTORY
A 37-year-old man presents to dermatology for refill of his rosacea medication, at which time the clinician notices an entirely incidental deformity of the patient's fingers. The patient says his "crooked little fingers" have been present since birth, and he claims to be otherwise healthy. There is no family history of serious medical problems, and the patient denies any issues with the function of his fingers or hands.
EXAMINATION
The fifth fingers of both hands are markedly curved inward, effectively shortening the fingers, but without any rotational curvature. No other defect can be seen in the fingers. The patient's appearance is otherwise unremarkable.
DISCUSSION
Physical diagnosis is a skill unto its own in medicine, spilling over into every specialty. Many findings are subtle, but some are so obvious as to escape detection—as in the case of this patient, who said no medical provider he'd ever seen had mentioned his fingers.
I was ignorant of what this defect might represent, or even what it was called. But I'm aware of a good "rule of thumb," which is: If it looks like something, it probably is. In other words, if it looks like it ought to have a name, it probably does—and it probably has implications that are potentially meaningful.
I promised the patient I'd find out what his deformity was called, and even though it took a while, I was able to do just that. (In retrospect, I should have simply asked an orthopedic PA, but instead I did an Internet search for "deformities of the fingers.") Here is what I found:
This patient's diagnosis was clinodactyly, a radial curving of the fingers. The fifth is most likely to be affected, though other fingers may be involved, and the condition is usually bilateral, as in this case. Although I wasn't familiar with it, clinodactyly is quite common: It affects 1% to 20% of children, appearing either at birth or shortly thereafter. Most commonly, it is insignificant and does not affect normal function.
However, up to 80% of Down syndrome patients have clinodactyly, and it has been associated with many other syndromes, usually as an incidental finding. Its presence in an infant should prompt a search for any other possibly related phenomena. Likewise, when seen on a prenatal ultrasound, chromosomal analysis is indicated.
Classified as to degree of involvement, clinodactyly presents in several variations. The basic defect is in the wedge shape of the distal phalanx, which should be rectangular. Extreme cases can require surgery to restore normal function and appearance.
As one would expect, there are a huge number of deformities of the fingers, with infinite variations. For example, children can be born with fingers fused together, a condition called syndactyly. Camptodactyly is a type of deformity in which there is a fixed-flexion deformity of a finger. All of these can be part of an inherited condition, usually in an autosomal dominant mode of transmission.
Obviously, this patient had suffered little if at all with his condition, though he recalled being ashamed as a child because his fingers were so different from his peers'.
TAKE-HOME LEARNING POINTS
• Clinodactyly is common, affecting 1% to 20% of all newborns, and is usually a normal variant.
• However, it has been associated with many other diseases and syndromes, most notably Down syndrome.
• It is therefore reasonable to search for other related abnormalities.
• Clinodactyly is a good example of the principle: If it looks like it's "something," it probably has a name and implications for the patient's health.