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The Bee Sting Pain Index

By Magdeline Lum

A PhD student has subjected himself to repeated bee stings over 38 days to compare the most painful places to be stung.

Research published in PeerJ has produced the first preliminary bee sting pain index to compare the severity of pain between sting sites. PhD candidate Michael Smith of Cornell University subjected himself to bee stings over 38 days to compile the index.

Pain can be difficult to measure as it is a subjective experience. However, a study carried out by entomologist Justin Schmidt had previously created a scale comparing the pain delivered by different stinging insects. This scale is known today as the Schmidt Sting Pain Index, and is accompanied with descriptions of the pain delivered.

The limitation of this index is that it does not compare how the pain delivered varies between sites. Some body parts are more sensitive to sensation than others, and Smith’s new study aimed to shed light on this.

Smith was methodical in his approach and recording of the study. Bees were collected “haphazardly with forceps” before they were pressed against one of the 25 predetermined test sites. The stinger was left in the sting site for a minute before removing it, and the pain was rated on a scale of between 1 and 10. To strengthen the rigour of the results, Smith’s records of pain for each site were kept hidden during repeated trials.

The application of stings was recorded with descriptions like: “Some locations required the use of a mirror and an erect posture during stinging (e.g., buttocks)”.

Cornell University’s ethical considerations were also met, as were the Helsinki Declaration of 1975 which provides a set of ethical principles surrounding human experimentation. “Cornell University’s Human Research Protection Program does not have a policy regarding researcher self-experimentation, so this research was not subject to review from their offices. The methods do not conflict with the Helsinki Declaration of 1975, revised in 1983. The author was the only person stung, was aware of all associated risks therein, gave his consent, and is aware that these results will be made public.”

Smith found that the three most painful sting locations were the nostril, the upper lip and the penis shaft, with average pain scores of 9, 8.7 and 7.3, respectively. Stings to the nostril were

described as “especially violent, immediately inducing sneezing, tears and a copious flow of mucus”. Smith contemplated that the copious flow of mucous may be a response to prevent further attack to the area during a normal stinging event.

The three least painful places to be stung by a bee were the skull, the tip of the middle toe and the upper arm, all scoring 2.3. Smith surmised that the sting depth may be a factor.

Skin is thinnest on the genitals followed by the face. Smith also considered that the nose and lips are orifices and may have lower pain thresholds as a protection mechanism for the human body.

Smith points out that his study cannot be generalised for the wider population as its sample size of one person does not allow for this. He concludes: “It is possible that if other people were tested, they would not rank the painfulness of the stings in the same way, or perceive pain similarly by location. Although these findings cannot be generalized, they are still interesting.”