Bruises or Contusions - A contusion is an effusion of blood into the tissues, due to the rupture of blood vessels (veins, venules and arterioles), caused by blunt trauma, such as fist, stone, stick, bar, whip, boot, etc.
Contusions may be present not only in skin, but also in internal organs, such as the lung, heart, brain and muscles. It is usually situated in the corium and subcutaneous tissues, often in the fat layer.
In contusion, there is a painful swelling, and crushing or tearing of the subcutaneous tissues usually without destruction of the skin. The extravasated blood is diffusely distributed through the tissue spaces, and the margins are blurred.
Bruises may be seen in association with abrasions (abraded-contusion) or lacerations. When a large blood vessel is injured, a tumor-like mass called haematoma is formed.
Petechial bruises are finely mottled or stippled. If the petechiae become larger and confluent, they are called ecchymoses. A fresh one is usually tender and slightly raised above the surface of the skin, and even a deep-seated one shows some swelling when compared with the opposite limb or part of the body.
It has lighter color in the center because extravasated blood is pushed outward by the impact. Mongolian spot (hyperpigmerted skin in the lumbosacral region) should not be confused with contusion.
Bruises vary in size from pinhead to large collections of blood in the tissues. The size of it is slightly larger than the surface of the agent which caused it, as blood continues to escape into the area.
Development of marked tissue swelling in the vicinity of a bruise usually results in loss of its original shape.As a general rule, the greater the force of violence used, the more extensive will it be.
Factors modifying size and shape
(1) Condition and Type of Tissue : If the part is vascular and loose, such as face, vulva, scrotum, a slight degree of violence may cause a large bruise, as there is sufficient space for blood to accumulate. If they are strongly supported, and contain firm fibrous ones and covered by thick dermis, such as abdomen, back, scalp, palms and soles, a blow of moderate violence may produce a comparatively small one. In boxers and athletes, bruising is much less because of good muscle tone.
Bruising is not seen if the injured part is thickly covered, or if the weapon used is a yielding one, such as sand bag. Bruising may be absent if the pressure be continued until death occurs. Even a severe injury may produce little hemorrhage, if it was preceded by an injury which produced deep shock.
Resilient areas, such as the abdominal wall and buttock bruise less. Bruising is relatively more marked on tissues overlying bone. Chronic alcoholics get it easily. Bruising of the scalp is better felt than seen. Bruising of the scalp with fluctuant centers can simulate depressed fracture.
(2) Age : Children get it more easily because of softer tissues and delicate skin, and old persons get it easily because of loss of flesh and cardiovascular changes.
(3) Sex : Women bruise more easily than men, because the tissues are more delicate and subcutaneous fat is more. Fat people also get it easily, because of greater volume of subcutaneous tissue. A slight pressure with the fingers on the arm of a woman, and especially if she is obese and not accustomed to work or exercise, may produce a definite bruise.
(4) Color of Skin : Bruising is more clearly seen in fair-skinned persons than those with dark skin, in whom they may be better felt than seen. The areas of extravasated blood appear darker even on heavily pigmented negroid skin. If the body is embalmed, skin bruises become more prominent probably (1) by forcing of additional blood into the damaged area, (2) increased transparency of overlying skin, and (3) formation of a dark pigment complex. Contusions appear much more clear in black and white photographs than by direct observation. Colour photographs more truly reproduce contusions.
(5) Natural Disease : When the vessels are diseased as in arteriosclerosis, bruising occurs very easily and may even result from coughing or slight exertion. In children, small bruises may be caused by the violent coughing as in whooping cough. Prominent bruising following minor trauma is seen in a person suffering from purpura hemorrhagic, leukaemia, haemophilia, scurvy, vitamin K and prothrombin deficiency and in phosphorus poisoning. Purpuric areas are clearly delineated from the surrounding and never show swelling.
(6) Gravity Shifting of the Blood : Bruises do not always appear at the site of impact. A deep bruise, especially that due to the crushing of tissue against the bone may take a long time to become visible and also may not appear below the actual point of impact. Blood will track along the fascial planes (or between muscle layers) which form the least resistance and may appear where the tissue layers become superficial (ectopic bruising, or percolated or migratory contusion).
Hemorrhages in the soft tissues around the eyes and in the eyelids (spectacle haematoma; black eye), may be caused by
(1) direct trauma, such as a punch in the eye,
(2) blunt impact to the forehead, the blood gravitating downwards over the supraorbital bridge,
(3) fracture of the floor of the anterior fossa of the skull.
The one behind the ear may indicate a basal fracture, rather than a direct blow behind the ear. In fracture of the jaw, it may appear in the neck. In fracture of the pelvis, it may appear in the thigh. In fracture of the femur, it may appear on the outer side of the lower part of the thigh. A blow to upper thigh may appear as a bruise above the knee. A kick on the calf of the leg may appear as a bruise around the ankle. The site of it does not always indicate the site of the violence.
A patterned contusion is one in which the size and shape mirror a portion of the object which caused it. With heavier impacts or objects, the tissues beneath the impacting objects are crushed, and the contusion pattern is solid rather than outlined.
(1) It is usually round, but it may indicate the nature of the weapon especially when death occurs soon after infliction of injury. If the person is living, this pattern may become obscure as the area of bruising tends to extend and merge with adjacent structures.
(2) A blow from a solid body, such as a hammer, or the closed fist usually produces a rounded one.
(3) Bruises made by the end of a thick stick may be round, but if any length of the stick hits the body, they are elongated and irregular.
(4) A blow with a rod, a stick or a whip produces two parallel, linear hemorrhages (railway line or tram line type).
The intervening skin appears unchanged, because the rod forcibly dents the tissues inwards and momentarily stretches each side of the dent. This causes rupture of vessels in the marginal zones with a line of bruising, whereas the base of the dent becomes compressed and the vessels are not injured.
Blood from the base of the dent gets displaced to the sides due to the pressure by the object. When the rod is removed and the skin comes back to its normal position, the two sides of the depression remain as contused lines.
In the one produced by a long rigid weapon, e.g., stick, the edges of the bruise may be irregular and the width may be greater due to infiltration of blood in the surrounding tissues along the edges of the bruise.
A blow with a rigid weapon like a stick on a curved surface of the body, in a region where the soft tissues are particularly pliable, e.g., the buttocks, compress the tissues under the force of impact. In such case, the contusion is not limited to the maximum convexity of the affected part, but it may extend over the whole of the curved surface.
(5) When the body is struck by a broad flat weapon, such as a plank, the edges of the plank may cause parallel bruises in the skin, separated by apparently normal tissue.
(6) Bruises caused by blows from whips are elongated, curve over prominences, and may partially encircle a limb or the body. They are seen as two parallel lines, the distance between which is roughly equal to the diameter of the whip.
(7) Bruises made by pliable canes are similar to those due to whip, but never encircle a limb or curve round the sides of the body.
(8) Bruises from straps, belts or chains, leave a definite imprint.
(9) A woven, spiral or plaited ligature may sometimes produce a patterned one.
(10) Contact injuries from firearms may produce abrasion with bruising indicating the outline of the muzzle of the weapon.
(11) Patterned bruising is also seen in motor car accidents.
(12) Suction or biting on sides of the neck or the breasts, during erotic love-making or sexual intercourse produces elliptical patterned bruises. They frequently consist of a shower of petechial hemorrhages, which may be confluent. They may sometimes reproduce the shape of the upper and lower lips.
(13) The one caused by impact with a patterned object, the hemorrhage which is relatively small may be sharply defined if it lies in the immediate sub epidermal layer, but the pattern is distinct due to translucency because of the thin layer that overlies it. Such contusions are commonly seen when the impacting object has alternating ridges and grooves (such as the tread of a motor Tyre in a traffic accident) as the skin will be forced into the grooves and distorted. Intradermal bleeding will occur and the red lines may be produced not by the ridges but by the grooves, by a squeezing or bursting effect on the cutaneous capillaries.
(14) Forceful compression with the sole or the heel may imprint an intradermal one of the pattern of the sole or heel of the shoe. Kicking and jumping on a person combined is known as ‘stomping’.
(15) If a violent blow is struck on a clothed area of the body, or if the clothing is grabbed and twisted over the skin, petechial hemorrhages occur within the skin reproducing the texture of clothing.
A superficial one appears immediately as a dark-red swelling. A deep one may take several hours, or one or two days to appear and deeper extravasation of blood may never appear. Therefore, one more examination should be carried out 48 hours after the first examination, to note bruises of slower development.
Occasionally, when an injury is produced before death, it may appear some time after death, due to further escape of blood from the ruptured vessels due to gravitation, and rapid haemolysis of stagnant blood, the pigment diffusing locally and producing a stain on the surface.
This may explain the difference of opinion between two observers, who have examined the person or the body at different times. The pressure of the gases of putrefaction may cause the extravasated blood to extend along the tissue spaces and give rise to a false impression of the extent of antemortem bruising. Haemolysis of extravasated red cells and diffusion of pigment into the surrounding tissues may also cause postmortem extension of bruise.
Therefore, in assessing the extent of bruising, the postmortem interval should be considered. The examination of whole body by ultraviolet light will sometimes clearly show otherwise undetectable areas of bruising.
At autopsy, when the superficial tissues are drained of blood, contusions may become more prominent and extensive than before. Surgical removal of the corneas for transplant purposes can cause hemorrhage in the eyelids simulating antemortem trauma. Removal of the vitreous soon after death can also cause scleral hemorrhage.
Deep Tissue and Organ Contusions
All organs can be contused. A contusion of the brain may initiate enough swelling with gradual accumulation of acid by-products of metabolism, with further swelling and impairment of function, confusion, coma and death.
Contusions in vital centers, e.g., which control respiration and blood pressure can be fatal, even when very small. A small contusion of the heart can cause serious disturbance of normal rhythm or stoppage of cardiac action and death.
Large contusions often prevent adequate cardiac emptying and lead to heart failure. Contusions of other organs may cause rupture of that organ with slow or rapid bleeding into the body cavity, and may cause death.
The Age of Bruise
It heals by destruction and removal of the extravasated blood. The more vascular the area, the smaller the contusion, and the healthier the individual, the more rapid will be the healing. The red cells disintegrate by haemolysis, and the hemoglobin is broken down into haemosiderin, haematoidin and bilirubin by the action of enzymes. Factors affecting contusion colors include:
(1) depth of bleeding,
(2) amount of bleeding,
(3) environmental lighting, and
(4) overlying skin color.
The color change starts at the periphery and extends inwards to the center.
At first : Red.
Few hours to 3 days : Blue.
4th day : Bluish-black to brown(haemosiderin).
5 to 6 days : Greenish (haematoidin).
7 to 12 days : Yellow (bilirubin).
2 weeks : Normal.
The rate of color change is quite variable, not only between persons, but in the same person and from bruise to bruise. Bruises in children change colour rapidly and may be completely absorbed in a few days. In interpreting the age of it by color changes, one should be very cautious.
When bruising is extensive and deeply situated, the color takes a longer time to appear externally. Towards the end stage of healing process, large histiocytes containing coarse granules of haemosiderin pigment can be seen microscopically in section of contused area.
The site of it may contain crystals of haematoidin for a long period after the injury. It is difficult to estimate the exact age of a bruise with any degree of certainty even by microscopic examination.
Subconjunctival ecchymoses do not undergo usual color changes. They are at first bright red, then yellow before disappearing. In old people, healing of it is very slow. A bruise sustained at the time of carbon monoxide poisoning is likely to have a bright-red colour.
Antemortem and Postmortem Bruising
In antemortem bruising, there is swelling, damage to epithelium, extravasation, coagulation and infiltration of the tissues with blood and colour changes. These signs are absent in postmortem bruises.
Contusions and abrasions produced immediately before death show a marked decrease in the acidic mucopolysaccharides of the connective tissue ground substance, as demonstrated by Alcian Blue or dialyzed iron technique.
Acidic mucopolysaccharide is absent in contusions more than an hour old, but reappears in the bruises several days old showing the increase of connective tissue. On microscopic examination, the presence of tissue reaction of a degree beyond a margination and limited emigration of the white cells indicates that the contusion was probably antemortem.
If the red cells have lost their shape and staining characteristics, and if iron containing pigment is found either at the site of injury or in the regional lymph nodes, probably 12 hours have passed after the injury.
It is of some value in distinguishing cerebral hemorrhage occurring due to accident from natural hemorrhage, which could have been occurring for some time, and which may have caused the accident.
Appreciable bruising does not occur 2 minutes after death due to arrest of circulation, but by using great violence, small bruises can be produced up to 3 hours after death, in areas where the tissues can be forcibly compressed against bone and also in hypostatic area, e.g., the back of the scalp, if the body is dropped on the ground, or on trolleys or postmortem tables.
The margins of postmortem bruises are usually quite sharply defined, and those of antemortem bruises are less sharp or indistinct for the greater part, indicating vital reaction in the damaged tissues.
Sometimes, hemorrhages are seen in areas of lividity on the arms or shoulders of fat persons without evidence of trauma on other parts of the body. These hemorrhages are produced by tearing of small veins in the skin when the body is lifted from the scene of death.
At autopsy blood drains from blood vessels so that the deep bruises may show up against the white areas as the blood in the contusions will not drain.
In decomposed bodies, especially in the scalp, haemolysis of red cells produces a diffuse discoloration of the soft tissues, due to which it becomes impossible to differentiate between an antemortem contusion and an area of postmortem hypostasis.
In hypostatic areas blood vessels breakdown with leakage of red cells into the soft tissue which haemolyse due to decomposition; erythrocytes in soft tissue in a contusion also haemolyse, and as such the appearances are similar.
Proof of Bruising
At autopsy, bruises may not be readily detected or they may be obscured by patches of postmortem lividity, or by the dark colour of the skin. Contusions of the scalp can be demonstrated by reflecting the scalp and making incisions into the scalp from the aponeurotic surface. Contusions of the neck can be demonstrated by reflecting the various structures of the neck in layers.
Contusions in the subcutaneous tissues may be detected by parallel incisions through the skin. Deep bruises are detected by deep incisions made into the muscles. When in doubt, a portion must be taken for microscopy. The extent of bruising and the injury to the underlying soft tissues and muscles can be seen by dissecting the skin away from the underlying fat and muscle fascia.
(1) Patterned bruises may connect the victim and the object or weapon, e.g., whip, chain, cane, ligature, vehicle, etc.
(2) The age of the injury can be determined by color changes.
(3) The degree of violence may be determined from their size.
(4) Character and manner of injury may be known from its distribution.
(5) In open wounds, dirt, dust, grease or particles of stone or sand are usually present, which may connect the injuries to the scene of crime.
Bruises are of less value than abrasions because:
Artificial Bruises : Some irritant substances, when applied to skin produce injuries, which simulate bruises. They are produced to make a false charge of assault.
CIRCUMSTANCES OF INJURIES
Accidental bruises are very common and may be seen on prominences, such as the forehead, nose, elbows and knees. Presence of mud, sand, grease or oil gives an idea of the manner of causation.
Multiple contusions from minor trauma are often seen in alcoholics, which may be mistaken to be caused by physical violence. Self-inflicted bruises are rare, as they are painful.
They are seen over accessible areas, usually on the head, especially in a hysterical individual or the insane. Homicidal bruises may be seen on any part of the body. It is not possible to differentiate an injury caused by a fist or weapon and a fall.
Contamination of the wound should be looked for Tangential forces or glancing blows may tear large flaps of tissue, exposing the underlying skull.