# Mathematics of Intralesional Injection

Mathematics of Intralesional Injection Abstract INTRALESIONAL injection of a corticosteroid suspension is a well-known and accepted treatment of several dermatological conditions. Some clinicians utilize a large bore syringe or an intermediate size syringe with a finger-ring attachment in an attempt to overcome the high degree of resistance characteristic of certain lesions. For example, injection of keloids with such an apparatus is often difficult and attended by considerable frustration. The mathematical interpretation to follow emphasizes that such consequences are unnecessary and explains why a small bore syringe will reduce the effort required. To explain the principle, two assumptions are prerequisite: (1) The pressure is a constant and (2) fluid flow is small. The system is, therefore, quasistatic and independent of needle size. Pressure is produced by a force applied to the syringe piston. For an applied force (F), the resulting pressure (P) equals the force on the piston divided by the cross sectional areaof References 1. Weber, R.L.; Manning, K.V.; and White, M.W.: College Physics , (ed 4), New York: McGraw-Hill Publishing Co., 1965. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Archives of Dermatology American Medical Association

# Mathematics of Intralesional Injection

, Volume 99 (4) – Apr 1, 1969
1 page

## Mathematics of Intralesional Injection

Abstract

Abstract INTRALESIONAL injection of a corticosteroid suspension is a well-known and accepted treatment of several dermatological conditions. Some clinicians utilize a large bore syringe or an intermediate size syringe with a finger-ring attachment in an attempt to overcome the high degree of resistance characteristic of certain lesions. For example, injection of keloids with such an apparatus is often difficult and attended by considerable frustration. The mathematical interpretation to...

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Publisher
American Medical Association
ISSN
0003-987X
eISSN
1538-3652
DOI
10.1001/archderm.1969.01610220105018
Publisher site
See Article on Publisher Site

### Abstract

Abstract INTRALESIONAL injection of a corticosteroid suspension is a well-known and accepted treatment of several dermatological conditions. Some clinicians utilize a large bore syringe or an intermediate size syringe with a finger-ring attachment in an attempt to overcome the high degree of resistance characteristic of certain lesions. For example, injection of keloids with such an apparatus is often difficult and attended by considerable frustration. The mathematical interpretation to follow emphasizes that such consequences are unnecessary and explains why a small bore syringe will reduce the effort required. To explain the principle, two assumptions are prerequisite: (1) The pressure is a constant and (2) fluid flow is small. The system is, therefore, quasistatic and independent of needle size. Pressure is produced by a force applied to the syringe piston. For an applied force (F), the resulting pressure (P) equals the force on the piston divided by the cross sectional areaof References 1. Weber, R.L.; Manning, K.V.; and White, M.W.: College Physics , (ed 4), New York: McGraw-Hill Publishing Co., 1965.

### Journal

Archives of DermatologyAmerican Medical Association

Published: Apr 1, 1969