Leeches are parasitic blood-sucking aquatic or land-based invertebrates. Aquatic leeches are worldwide, have relatively weak jaws, and usually attach to thinner tissues such as the pharynx or vagina. Land leeches are primarily found in tropical and subtropical areas of Asia, the South Pacific, and South America; typically have powerful jaws; can attach to any body surface; are fast and painless feeders; and often detach from the host without being noticed.
Leeches have been historically used for bloodletting, their saliva used to derive modern anticoagulants, and are considered currently for elimination of venous congestion after microvascular surgery. They are not known to directly transmit infectious diseases, but bacterial infection can follow bites. Leeches are prodigious feeders; large infestations can cause anemia. Bites from detached land leeches can bleed for prolonged periods due to injected anticoagulants. Allergic and anaphylactic reactions may occur. Aquatic leeches have potential to cause complications, particularly when attached within the esophagus or airway.
Leech. Nonengorged leech attached to thigh of patient in remote area of Tasmania. (Photo contributor: Seth W. Wright, MD.)
Leech. Engorged leech attached to toe of a backpacker in Papua New Guinea. (Photo contributor: Seth W. Wright, MD.)
Management and Disposition
Treatment of detached leech bites consists of local wound care, hemostasis if needed, tetanus prophylaxis, and antibiotics if secondarily infected. Attached leeches can be detached by using a fingernail to break the suction under the sucker. Other modalities (perhaps associated with increased risk of infection or injury) have been suggested, including saline solution, vinegar, or a lighted match.
The presence of a small y-shaped lesion on the lower extremity suggests a detached land leech bite.
Aeromonas infections have been reported following use of medicinal leech therapy. Ciprofloxacin may aid in prevention.
Hemostasis with QuikClot gauze has been reported to be effective in patients with prolonged bleeding.
Leech. Leech bite wound on the leg seen after detachment of a land leech. Note the sharp wound edges and surrounding ecchymosis. (Photo contributor: Seth W. Wright, MD.)