Ainhum

Ainhum (from Portuguese, pronounced īn-yoom´, i´num or ān´hum; also known as dactylolysis spontanea) is a painful constriction of the base of the fifth toe frequently followed by bilateral spontaneous autoamputation a few years later. Ainhum (from Portuguese, pronounced īn-yoom´, i´num or ān´hum; also known as dactylolysis spontanea) is a painful constriction of the base of the fifth toe frequently followed by bilateral spontaneous autoamputation a few years later. The groove begins on the lower and internal side of the base of the fifth toe, usually according to the plantar-digital fold. The groove becomes gradually deeper and more circular. The rate of spread is variable, and the disease may progress to a full circle in a few months, or still be incomplete after years. In about 75 per cent both feet are affected, though not usually to the same degree. There is no case reported where it begins in any other toe than the fifth, while there is occasionally a groove on the fourth or third toe. The distal part of the toe swells and appears like a small “potato”. The swelling is due to lymphatic edema distal to the constriction. After a time crusts can appear in the groove which can be infected with staphylococcus. While the groove becomes deeper, compression of tendons, vessels and nerves occurs. Bone is absorbed by pressure, without any evidence of infection. After a certain time all structures distal the stricture are reduced to an avascular cord. The toe’s connection to the foot becomes increasingly slender, and if it is not amputated, it spontaneously drops off without any bleeding. Normally it takes about five years for an autoamputation to occur.