This article is only available in the PDF format. Download the PDF to view the article, as well as its associated figures and tables.
There is a quite general belief that an intradermal injection to be properly given must be injected into the epidermal layers of the skin. It is considered that the typical "bleb" which results from such an injection represents a division of the epidermal layers of the skin. When this is not accomplished the procedure is considered incorrectly performed.
The fallacies of injection into the deeper layer of the skin (corium) have been repeatedly pointed out. In figure 1 are shown diagrams taken from two recent discussions. On the left is indicated the "correct" method of intradermal injection with the needle point plainly in the epidermal layer. On the right is shown the "wrong" site of injection with the needle beneath the epidermal layer. It was my opinion that no human hand could be so accurate. Though some of the injected fluid might reach the indicated desired site, certainly the majority
Taylor FW. ACTUAL SITE IN SKIN OF INTRADERMAL INJECTION. JAMA. 1938;111(27):2475-2476. doi:10.1001/jama.1938.72790530003009a