Allergy bracelet

A medical identification tag is a small emblem or tag worn on a bracelet, neck chain, or on the clothing bearing a message that the wearer has an important medical condition that might require immediate attention. The tag is often made out of stainless steel or sterling silver. The intention is to alert a paramedic, physician, emergency department personnel or other first responders (emergency medical services, community first responder, Emergency medical responder) of the condition even if the wearer is not conscious enough, old enough, or too injured to explain. A wallet card with the same information may be used instead of or along with a tag, and a stick-on medical ID tag may be added or used alone.

A type of medic identification alert is the USB medical alert tag, essentially a USB flash drive with capacity to store a great deal of emergency information, including contacts and medical conditions. This information is accessible by any computer with a USB port. However, the practical effectiveness of such a system is limited in many cases by medical computer systems that restrict the use of USB devices which may carry malware. It is also possible that a device carried by an unconscious person may not be their own, or not be up to date, with concomitant risks to health and legal liability of medical personnel.

Another new type of medic identification alert is QR code based medical alert stickers. The QR code on the sticker links to a web service that contains the individual's emergency information. The information is accessed by any first responder or emergency personnel by scanning the QR code by using a smartphone. Since a web service is used to store the information there is normally no limitation of how much information that can be stored.

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Wikipedia