Assessing the age of wounds and scars

In documenting the physical sequelae of torture and ill-treatment it is sometimes important to seek to determine the date of infliction of the injuries responsible for wounds and scars found on clinical examination.

However, even in the most experienced and expert hands, the process is inexact for the following reasons:

1. The dynamic process of healing which leads from acute wound to a static scar involves the sequential actions of many different kinds of cells. It requires the coordinated ingress of these populations, followed by proliferation, elaboration, deposition and modification of large molecules outside these cell, and eventually the disappearance of the overwhelming majority of those cells[1]. The general schema of inflammation, proliferation, maturation and cellular disappearance within the “temporary organ of repair”[2] is robust. However the time course and outcome of repair are highly variable and affected by numerous factors. These include, but are not limited to:
2. The nature of the causative injury: blunt or sharp trauma vs high velocity bullet vs shrapnel vs electrical, thermal, or chemical burns etc, which result in different degrees of damage (such as superficial, partial thickness or full thickness burns) and leave different amounts of dead tissue in their wake.
3. The location of the injury: for example, skin damage in tissues with a rich blood supply such as the face ordinarily heal more rapidly and with less residual scarring than that over the tibia where vascularity is poor.
4. Treatment: the timeliness and adequacy of suturing a wound, or excising dead tissue (debridement) clearly alters the rate and extent of repair.
5. Impediments to healing: infection with various bacteria and with varying effects, pre-existing medical conditions such as diabetes.
6. Intrinsic genetic variation: less is known of this, but every experienced clinician will be aware of patients who have healed wounds rapidly and well and others in whom repair is delayed and less effective.
7. In attempting to “age” a scar under those circumstances the clinician can usually rely only on visual (and to a lesser extent tactile) properties of the lesion(s) observed (e.g. what they can see and feel with their finger tips.) The inutility of more complex investigations (which are potentially feasible) is discussed below.

This means that only visible and palpable (and therefore quite gross) characteristics of the healing sequence are available to the assessing clinician. These are inevitably quite crude:

1. is there crusting (in a burn) or odour and discharge in an infected wound?
2. is there redness (erythema) indicative of an enhanced blood supply (resulting from the ingrowth of new vessels or angiogenesis[3] and opening up of pre-existing vessel, known as vasodilatation. Near the completion of repair, this blood supply decreases and the redness disappears.)
3. is the healing tissue raised above or depressed below the level of the surrounding skin; is it more or less elastic than the surrounding normal skin or a mirror image site on the body?
4. The normal colour of the person’s skin is therefore relevant. It is far more difficult to see redness (eg persistence of an enhanced blood supply) in a wound in dark skin.

Various experts have attempted to provide schemata for the evaluation of the ages of wounds. By way of example, in the case of KV[4] Dr. Zapata-Bravo (a general physician and psychiatrist, following Forrest[5]) gave the time to completion of healing as six months, The author of this note cited a time of one year (using a schema mentioned below) and Ms. Odili (a plastic surgeon) said that it was up to two years. This difference was accepted by the court (correctly in the view of the author of this note) as arising at least in part from the different clinical backgrounds and approaches used by the different experts.

These differences illustrate the degree of uncertainty in assessing the age of wounds. They show that, at the present stage of knowledge, and using only the limited observational tools available in the context of a medico-legal examination conducted to the standards of the Istanbul Protocol[6] there remains a very wide range of uncertainty in the determination of scar (or wound) age.[7]

The Inutility of Complex Investigations

In theory, a variety of tests could be used to establish the ages of wounds and scars. These include non-invasive techniques such a scanning laser-Doppler perfusion imaging and analyses of blood or tissue samples (obtained by biopsy)

However, in order to calibrate measurements (e.g. give meaning to the results obtained from tests) in any particular case, a database of analyses from wounds of a particular kind and from a wide variety of ages would be required for purposes of comparison in order to establish a set of normative values.

While the establishment of a set of such normative values is theoretically possible to my knowledge no such data set exists. Further, the extent of variation within the distribution of values (of whatever substance) in earlier stages of healing is much greater than in later stages, as the rate of biological change slows as healing reaches its conclusion in a static scar. Thus the nearer a maturing scar is to quiescence the smaller the difference between measurements made on it now and over the years to come and the greater the uncertainty in the resulting evaluation.

References:

1. Cherry GW, Hughes MA, Leaper DJ, Ferguson MWJ. Wound healing. In: Morris PJ, Wood WC, eds. Oxford textbook of surgery. 2nd ed. Oxford: Oxford University Press, 2001:129-59
2. Florey H. General pathology 4th edition Philadelphia, W. B. Saunders, 1970
3. Arnold F, West DC. Angiogenesis in wound healing. Pharmacol Ther. 1991; 52:407.
4. KV (scarring – medical evidence) Sri Lanka [2014] UKUT 230, para 115.
5. Forrest D. Guidelines for the Examination of Survivors of Torture (2nd edition).
6. http://www.freedomfromtorture.org/sites/default/files/documents/Forrest,%20guidelines,2002.pdf
7. Arnold F. Treatment and management of wounds and scars of torture. Wounds UK. 2009; 5: 60.
8. The Istanbul Protocol is silent on the age of scars.