Intradermal injector

An injection device, comprising:

• a housing;
• a chamber within the housing, the chamber configured for containing a substance to be injected;
• a needle having a delivery end, the needle being operatively associated with the chamber and configured to deliver the substance to an intradermal injection site, the needle configured to move between a retracted position and an extended position in which the needle is disposed for penetrating a patient and injecting the substance;
• a resilient needle cap covering the delivery end in the retracted position, wherein the resilient needle cap is in a relaxed configuration when the needle is in the retracted position and a compressed configuration with the needle in the extended position, wherein the resilient needle cap moves from the compressed configuration toward the relaxed configuration after an injection thereby retracting the needle from the extended position towards the retracted position;
• and
• a collar surrounding the needle and defining a collar cavity, the collar having a peripheral forward skin-contacting surface that surrounds and is radially spaced from the needle and injection site by an area that is sufficiently large to allow a patient's skin to move into the collar cavity,
• wherein the delivery end of the needle is within the collar cavity when the substance is delivered to the intradermal injection site.