Figure 3-13 Bacteria attach to skin.
Skin lesions can also be defined in a manner that is dependent upon their appearance. For example:
•Discreet – this type of lesion is distinct in size, shape, and spacing.
•Confluence – a group of lesions merged together. Example, urticaria.
•Linear – appear as a stripe, streak, or distinct line.
•Grouped – the lesions form into clusters that are grouped in a specific area. Example: contact dermatitis.
•Gyrate – this type of lesion looks like a snake or a worm.
•Polycyclic – this type of lesion has distinct rounded edges that are closely grouped to one another.
Figure 3-14 Dermatitis and normal skin.
Some skin problems are inherited, while others are due to inadequate diet or nutritional deficiencies. Others are caused by environmental conditions. Some are caused by disorders of the immune system.
■Common Causes of Skin Problems
A number of factors can contribute to common skin problems. Various forms of fungal bacterial and viral infections are common triggers. These can typically be described based on their pathophysiology. For example, see the lists of common skin infections and their classifications listed below:
Viral
•Herpes simplex
•Herpes zoster
•Warts
Acne
•Acne vulgaris
•Acne rosacea
Eczematous
•Contact dermatitis
•Atopic dermatitis
•Lichens simplex chronicus
•Seborrheic dermatitis
Fungal infections
•Candidiasis
•Tinea (tinea corporis/tinea cruris)
Bacterial infection
•Folliculitis
•Impetigo
•Boils (furuncles)
•Carbuncle
Figure 3-15 Sunbathing and skin damage.
More serious threats, but less common, are traumatic injury or disease to the skin, including cancers and burns.
Common skin threats
According to the American Academy of Dermatology, skin cancer is rated as a leading cause of cancer in the US, with estimations that one in five Americans has a likelihood of developing some type of skin cancer during their lifetime.19
Incident rates of skin cancer, types of skin cancer, survival rates, mortality rates, and risk factors have increased globally, with nearly 10,000 Americans diagnosed with skin cancer daily.20
One of the most prevalent contributory causes of skin cancer is overexposure to sunlight or UV radiation.
Most cancers are caused by mutations of DNA in skin cells. Three major types of skin cancer are most prevalently diagnosed:
•Basal cell carcinoma
•Squamous cell carcinoma
•Melanoma
The major cause of overexposure? Tanning.
Basal cell carcinoma is the most common form of skin cancer and the least malignant. Basal cell carcinoma typically appears on areas of the skin constantly exposed to sunlight, such as the face. It’s a slow-growing carcinoma, and in many cases, metastasizes before it’s even been noticed by the individual. The good news is that through surgical excision, a person has a 99% chance of cure.21
The second most common type of skin cancer is called squamous cell carcinoma. This type of cancer grows rapidly and will metastasize if not removed in a timely manner. In general, when caught early and removed through surgical excision or radiation therapy, prognosis is good.
Melanoma, otherwise known as cancer of the melanocytes, is the most dangerous and the most resistant to chemo-therapy. Melanoma is extremely metastatic. While not as common as basal cell or squamous cell carcinoma, it can prove deadly.
Figure 3-16 Tanning and skin cancer risk.
Most of us are (or should be) familiar with the ABCDs for recognizing a melanoma growth, which often starts out looking like a freckle or a mole. As a refresher:
•Asymmetry – one of the most recognizable signs of a melanoma is asymmetry, or a spot whose sides don’t match. For example, one side of the melanoma might be larger than the other.
•Border irregularities – a melanoma, unlike most freckles, is not round or rather consistent in shape. Its borders can look jagged or irregular.
•Color – a melanoma is a spot of pigmentation that can contain a variety of colors; dark brown, black, tan, and even a bluish or reddish tinge. Changes in color or tone are often noticeable.
•Diameter – most freckles and moles are not large, but the diameter of a melanoma is often measured by equating its diameter in millimeters to that of a pencil eraser. If the spot is larger than 6 mm, or larger than the average pencil, it may be a melanoma. Get it checked.
Another thing to watch for is changes in the size or shape of the spot. If it changes shape, grows, or seems to be evolving, this may also be a prime indication of melanoma.
The American Cancer Society recommends that we all take the time to regularly check our skin for any new appearance of moles, freckles, or spots, summer and winter.
Burns
Burns are another common skin threat that can leave the body vulnerable to multiple types of infection as well as limited mobility. Damage caused by burns is typically measured as:
•First – degree: Defining damage only to the epidermis. This is typical with sunburns that cause redness, tenderness, and some swelling. In most cases, a first-degree burn will heal within a few days.
•Second – degree: This type of burn damages not only the epidermis, but the upper layer of the dermis. Signs and symptoms are similar to that of first-degree burns (redness, pain, swelling), but also with the appearance of fluid-filled blisters. In most cases, the body heals from second-degree burns with little scarring within four weeks, as long as the individual takes care to protect the area from infection.
•Third – degree: The most severe degree of burn, a third-degree burn is also known as a full-thickness burn. It impacts all thicknesses of the skin. It can take a long while for such severe burns to heal, during which time the individual is vulnerable to infection as well as fluid loss. In such cases, skin grafting is a common option.
Figure 3-17 Burns measured in degrees.
Another common cause of declining skin