LETTER TO EDITOR
Asymptomatic adult-onset difference in foot size

Dear Sir,

It is generally accepted that the left and right foot in the same individual have slightly different size. Usually, the difference is very small and is associated with general asymmetry of the human body. More significant size differences result from inborn deformities, trauma or destructive disorders of the musculoskeletal system. The aim of the letter is to describe a patient with a significant difference in the size of the left and right foot that appeared in his fifth decade of life without known cause and remained asymptomatic. The 57-year-old male university teacher visited the rheumatologist and revealed that his left foot was longer than the right one. He discovered the size difference when he was about 45 years old, and the difference was progressive. There were no accompanying symptoms or signs, and the only problem he had was finding comfortable shoes. Physical examination confirmed the size difference (slightly over 2 cm) but no deformation or other abnormality was detected (Fig. 1). There was no history of trauma or disorders of the skeletal system and no vascular abnormalities. The length of both lower extremities was the same. The patient was right-handed, so enlargement of the left foot could not be explained by movement orientation. Radiological examination did not reveal differences in bone size between the feet. There were no other skeletal abnormalities except slight thoracic scoliosis. The medical history was negative, and apart from hay fever in adolescence and paroxysmal atrial fibrillation in recent years prior to the examination the patient did not suffer from any disorder. Laboratory findings were normal, including inflammatory indices, calcium-phosphate metabolism indices and thyroid hormone levels. The presented problem is rather minor for clinical practice. There are very few literature data concerning asymptomatic size difference of the feet. The hypothetical explanation of the observed phenomenon is local ligament alterations that result in a “loose” joint of the foot.

Eugeniusz J. Kucharz and Anna Kotulska