Yet, as an aid to child abuse diagnosis and perpetrator identification, visual aging of bruises remains an inexact science, despite recent composite charts that suggest otherwise.
Even though it has been stated that it is not possible to age bruises accurately based on color, these opinions have not been represented in the child abuse literature.
Interobserver reliability may also be assessed in such a study.
Photographs of a bruise, however, depending on available light and technique, may not represent color accurately. Future research should focus on a number of questions.
A study of the aging of bruises, using contusions of known age and history-blinded examiners, could determine how accurate clinical estimates are.
Unlike the severe abuse that was reported in early child abuse literature, more moderate injuries comprise 60% of physical child abuse.
These less-severe abuse cases, many with limited, ill-defined bruising, may be more difficult to diagnose than a severe case with multiple-system injury or a child with specific, clearly imprinted bruising.
Even for the practitioner to state, as Wilson suggests, that a particular bruise is "consistent with" a specific age implies a level of certainty not supported by the literature.
The study of Langlois and Gresham, to date the only research-based study of bruise aging by appearance, has not yet been cited in the medical literature (Science Citation Index search, August 1994).
The available literature does not permit the estimation of a bruise's age with any precision based solely on color.
Additionally, as the US Supreme Court observed, "Child abuse is one of the most difficult crimes to detect and prosecute in large part because there often are no witnesses except the victim.
Estimates of ages of bruises along with the aging of other injuries such as fractures and brain trauma may offer the only way to associate an injury with a particular perpetrator.
Of course, the practitioner must continue to describe the size, shape, location, and color of each bruise accurately.
This is best done by written description and drawings along with careful photographic representation.