A wound is caused by an external force whereas an ulcer is caused by an internal problem.
That was the short answer. The more extended explanation is the following:
In an ulcer, the primary tissue breakdown is internal, i.e. the lesion is caused by an underlying disease or other internal reason. This disturbance of the tissue will typically be gradual.
In a wound, the primary tissue breakdown is caused by a force originating from the external world and the disturbance of the tissue will typically be acute.
This is the logical and most updated definition of these two terms. It is based on the differences in appearance of the lesion, the cause (aetiology), the way the body responds (physiology) and disease processes (pathology). These factors are similar within each group (wounds versus ulcers) and from a medical perspective, the interventions required and treatment options available as well as potential outcomes share greater similarities within each group than compared to the other group (wounds vs. ulcers).
The inflammatory factors, proteases, immune cells as well as the microbiome on the surface of a lesion must be at a balance in order for healing to proceed. An unbalance is present in both ulcers and wounds that do not heal properly. However, these unbalances differ by their composition. Likewise, physiological differences in expression of cell types are encountered between wounds and ulcers. Ulcers could be said to be in a chronically inflamed state.
Dressing techniques and frequency often differ between ulcers and wounds. Ulcers are often dressed once or twice weekly at walk-in clinics. Major wounds usually require daily changes. e.g. major trauma (with excessive necrosis leading to excessive microbial growth, which leads to toxin release and excessive toxin absorption by the body) can lead to rapid death and therefore require acute and maybe extensive care.
The reason for this is the common assumption that mortality directly from ulcers is rare and, therefore, ulcers are considered of less clinical concern than wounds.
The death from a major trauma wound is definitely more spectacular and easily linked to the wound than the death from an ulcer.
Ulcers cause death in a much slower and invisble way. When ulcers become chronic, they host an array of bacteria and fungi directly next to the very thin-lined blood vessels (capillaries and venules) which makes them an easy and frequest entry point for these infecting agents into the blood stream causing septicaemia – also called blood poisoning – which is likely to be followed by sepsis / septic shock and death.
Also, chronic ulcers will often over time extend down to the bone surface and cause a secondary infection in the bone. Bone infection is also called osteomyelitis.
Finally, chronic wounds and ulcers often battle with skin infection in the skin surrounding the ulcer. This skin infection is called cellulitis.
Both osteomyelitis and cellulitis rank among the types of infection typically associated with sepicaemia and sepsis.
Consequently, ulcers are potentially more lethal than is presently commonly recognised.
The prevention of either an wound or an ulcer turning chronic is of paramount clinical importance.
Examples of ulcers are
– Venous leg ulcers – caused by cardiovascular disease
– Diabetic foot ulcers – caused by diabetes mellitus
– Pressure ulcers – caused by vascular stasis in the area
– Radiation burns – where the ionizing radiation penetrates deep into the tissue causing primary damage to the vascular structures which leads to skin lesions as secondary damage.
Examples of wounds are
– Trauma wounds – caused by accident
– Surgically induced wounds – caused by incision
– Thermal burns – caused by external heat
This definition of wounds versus ulcers has been used for many years. However, it has been defined here because it has been interrupted by a period in which the definition was based solely on the age of the lesion. Clinically this definition was a step backwards and not forwards as the age of any lesion can be described by the use of the words “acute” and “chronic”.
MPPT supports healing of both wounds and ulcers.
Reference:
Herman MH (2010) Wounds and Ulcers: Back to the Old Nomenclature. Wounds 22(11):289–293