Approach to skin and soft tissue injury: Clinical sciences

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Introduction0:00–0:42

Skin and soft tissue injury refers to damage to the skin and its underlying structures such as fat, fascia, muscles, tendons, and ligaments.
The majority of these injuries are caused by blunt or penetrating trauma, but they can also result from burns or infections.
Generally, skin and soft tissue injuries are categorized as either open or closed, ranging from superficial minor injuries to severe polytrauma involving the bone.
In severe cases, these injuries can even be limb or life-threatening, so timely diagnosis is very important.Alright, your first step in evaluating a patient presenting with skin and soft tissue injury is to perform the ABCDE assessment to determine if they are stable or unstable.

ABCDE Assessment0:42–1:22

If the patient is unstable, start acute management by stabilizing the airway, breathing, and circulation. Next, establish IV access and start IV fluid resuscitation.
Additionally, continuously monitor the patient's vital signs. Here’s an important clinical pearl to keep in mind!
Make sure to avoid the injured extremity when obtaining IV access and placing a blood pressure cuff or arterial line.Now that these important steps are done, you can move on to obtaining a focused history and physical exam as well as labs including CBC, CMP, arterial blood gas, and a urinalysis.

Unstable Patient1:22–3:18

Your initial assessment should be focused on identifying any life-threatening injuries and signs of impending hemodynamic collapse.
Unstable patients typically present with a history of severe traumatic injury, burns or rapidly progressing infection. On the physical exam, you might find altered mental status, tachycardia, and hypotension which are all signs of instability.
Additionally, you might see obvious skin or soft tissue injury with surrounding edema, erythema, and even an eschar. For open injuries, subcutaneous fat, muscle, or bone might be exposed.
On the flip side, with closed injuries like crush injuries, you can expect to see tense skin and soft tissue with severe edema and erythema along with reduced distal pulses and sensory motor deficits.
As for severe burns, you might see deeply scalded soft tissue with blisters containing clear fluid or blood. Lastly, if there is an underlying infection, you can expect to see purulent drainage and even crepitus.
Now, lab results typically reflect the severity of the injury and show leukocytosis, electrolyte abnormalities, metabolic acidosis, and even myoglobinuria.
Based on your findings, you can make your clinical diagnosis of life or limb-threatening injuries which include mangled extremity, compartment syndrome, severe burns, and necrotizing soft tissue infection, or NSTI.
Keep in mind that many of these injuries require emergent surgical intervention.Now that unstable patients are taken care of, let's talk about stable ones.

​​Stable Patients3:18–4:28

Your first step in assessing a stable patient with a skin and soft tissue injury is to perform a focused history and physical exam.
Let’s start with the most common cause which is traumatic injury. History often reveals the mechanism of injury such as blunt, penetrating, blast, or crush injury.
Bear in mind that penetrating injuries vary widely from gunshot wounds to stabbings to bites from animals and even humans.
Now, physical exam findings can differ depending on the mechanism of injury. Some injuries might be localized to a specific area of skin and soft tissue with surrounding edema and erythema, as well as tenderness to palpation.
Penetrating, blast, and sometimes crush injuries can have obvious open wounds with exposure of the underlying tissues. If blood flow to the skin is compromised, you might see dark discolorations and even necrosis.
All of these findings are indicative of a traumatic skin and soft tissue injury.Okay, now let’s discuss another type of injury, burns.

Burns4:28–6:13

In this case, history typically reveals direct contact with or exposure to open flames, chemicals, high-voltage electricity, radiation, or prolonged exposure to sunlight.
Patients might report pain for relatively superficial injuries. However, if the injury is deep, they usually won’t experience pain.
This is because the majority of sensory nerve endings reside in the dermis. So, when there is full thickness burn injury, those nerves die resulting in numbness and lack of pain.
Now, on a physical exam, you should be able to grade the burn injury. There are 4 grades ranging from superficial to deep.
Grade 1 burn injury is very superficial and limited to the epidermis resulting in mild erythema. Grade 2 injuries are partial thickness with dermal involvement.
They appear as red, moist injuries with blisters, and are severely tender. Next, grade 3 injuries are full thickness and extend to the subdermal soft tissues like fat.
These have a white or brown-black dry leathery appearance. Lastly, grade 4 burns are most severe involving the subdermal deep tissue extending to the bone.
These are usually dark in appearance like charred tissue. During your exam, make sure to check how much of the surface area is affected and if the injury is circumferential around a limb, which can lead to constriction of the limb decreasing blood flow.
Any of these clinical findings will support your diagnosis of a burn injury.Finally, let’s talk about infection-related skin and soft tissue injuries.

Infection 6:13–7:43

Oftentimes, infections arise from a previous injury or an existing open wound. As bacteria enter the wound, it can spread causing more destruction of the skin and its underlying soft tissue.
Remember, skin is not sterile and it is covered with bacteria that is part of the skin flora, but the structures beneath the epidermis are sterile.
So infection of that space with even skin flora can cause damage to the surrounding soft tissue. On history, patients typically report symptoms like fever and localized pain, as well as comorbidities such as diabetes, immunocompromised states, chronic ulcers, or open wounds.
Physical exam might reveal edema, erythema, tenderness, and warmth of the skin. You might also find palpable fluid collection, purulent drainage, crepitus, and necrosis.
These features are indicative of an infection, which can include cellulitis, abscess, and NSTI.Okay, let’s end with a clinical pearl!
One important variant of NSTI you should know is Fournier gangrene. This infection originates from perianal, retroperitoneal, or urinary tract infections that extend into the skin and soft tissue of external genitalia and perineum.Alright, as a quick recap… Skin and soft tissue injuries are diagnosed clinically.

Review7:43–8:06

In unstable patients, you should first assess for limb or life-threatening injuries like mangled extremity, compartment syndrome, severe burns, or NSTI.
When it comes to stable patients, you need to consider traumatic injuries, burns, or infections like cellulitis, abscess,