During a recent stint at a regional base hospital in NSW I was faced with an interesting clinical challenge that, at the time, I thought was most unusual. It appears I was wrong and the problem is well documented in the literature and fascinating in its gruesomeness!
Hang on to you breakfasts!
A middle aged lady presented to the triage desk stating that she had a leech on her uvula. The background was that she had been in the paddock after a night of heavy rains feeding her horses when she experienced a shower of rain water dislodged from the overhanging branches, looked up, and some went into her mouth. She thought little of it until an hour or two later when she felt discomfort and partial obstruction at the back of her throat. Looking in the mirror she spotted a dark object on the uvula which, on closer inspection appeared to be a leech. Being a stalwart individual the patient decided to remove the leech herself and tried swallowing salt, gargling salt water and grabbing it. All to no avail and so she came to ED.
On examination there was a 0.5cm X 1.5cm dark object in the uvula which was indeed a leech. Attempts to grab it with a pair of forceps just resulted in gagging and the uvula/leech being retracted into a tricky position in the oropharynx. It occurred to me that lignocaine spray would be useful in supressing the gag, but would also paralyse the leech making it let go. That could be a good or bad thing, it may assist in removal or may lead to the critter dropping off down the patients throat or worse trachea.
A few sprays later the leech did dislodge and true form I fumbled the catch. Fortunately the patient was wise enough to just swallow it!
I was both interested and revolted by the case and decided to see if it had happened before. A perfunctory search of anaesthesia and ENT literature revealed many case reports of leeches in the oro or laryngopharynx. Most had histories of drinking from streams in tropical or subtropical climes and then onset of airway obstruction over hours or days. Haemoptysis was common. Removal techniques usually involved fibreoptic evaluation and forceps removal after lignocaine spray. Significant bleeding was a rare complication.
Leeches are annelids belonging to the subgroup Hirudinea. They can be classified into fresh water, terrestrial and marine according to their habitat. A few of them are hemorrhagic parasites feeding on the blood of animals. They are hermaphrodites. Hirudiniasis is the term used to indicate the invasion of the body cavity or infestation by leeches. The species Dinobdella ferox (ferocious leech or nasal leech) are known to invade the nasal cavities.
Leeches attach themselves to human beings either on skin or the mucous membrane with the help of their caudal end and ingest blood by their suction appendage. A single leech can ingest ten times it’s body size in blood. The saliva of the leech contains a local anesthetic that limits the sensation to the host, thus the host does not attempt to remove it. The saliva also contains a potent vasodilator and also an anticoagulant called hirudin. Thus, the dilated vessels enable the leech to suck more and more blood without clotting.
One set of authors warned “A high index of suspicion of leech infestation should be considered in patients presenting with haemoptysis, hoarseness and respiratory distress and a history of recent contact with fresh water streams.” (1)
1) Aquatic leech as a rare cause of respiratory distress and hemoptysis. Mohammad Hossein Rahimi-Rad, Effat Alizadeh, Reza Samare. Pneumologia vol. 60, nr. 2, 2011
2) An unusual cause of epistaxis, anemia and upper respiratory tract obstruction, Leeches: Report of three cases. Engin Şengül, Salih Bakır, Cemile Arıkan Şengül, Ömer Erdur. Journal of Clinical and Experimental Investigations; 2012; 3 (3): 401-403
3) Leeches in the larynx. Labadi MH, Jamal MN. J Laryngol Otol. 1997 Oct;111(10):980-1.
4) Removal of a laryngeal leech: a safe and effective method. American Journal of Otolaryngology – Head and Neck Medicine and Surgery. Volume 24, Issue 5 , Pages 338-340, September 2003