Psoriasis and Skin Cancer Human Anatomy/Physiology

The Integumentary System

• Psoriasis -Psoriasis is a skin disorder that affects 7 million

Americans. It is characterized by keratinocytes that divide and move more quickly than normal cells from the stratum basal to the stratum corneum. The premature keratinocytes form flaky, silvery scales at the skin surface typically on the knees, elbows, and scalp (dandruff). Effective treatments are various topical ointments and UV phototherapy which is used to suppress cell division, decrease the rate of cell growth, or inhibit keratinization.

• Plaque Psoriasis

Plaque psoriasis is the most typical form of the disease. The characteristics include patches of red, raised skin. The buildup of flaky, silvery-white skin on top of the plaque is called a scale. The scale will continually come loose and shed from the plaque. The skin affected is usually very dry, and symptoms include skin pain, itching, and cracking.

Plaque Psoriasis

Guttate Psoriasis

• Guttate psoriasis appears in small, red, individual drops on the skin. Most often, they are seen on the torso and limbs, but sometimes on the scalp also. Typically, they aren’t thick or scaly like plaque psoriasis, but spread over the affected areas like chicken pox. This form of psoriasis often begins in childhood or young adulthood and is triggered by an infection of some sort.

Guttate Psoriasis

Inverse Psoriasis

Often called flexural psoriasis, this form is mainly found on the armpits, groin, under the breasts, and in other skin folds around the genitals and buttocks. The skin appears smooth, dry, red, and inflamed with no scaling. This condition is particularly subject to irritation from rubbing and sweating due to the location in the skin folds and tender areas. It’s more common and troublesome in overweight people.

Inverse Psoriasis

Erythrodermic Psoriasis

Although this is the least common form of psoriasis, it appears most often on people with unstable plaque psoriasis where the lesions are not clearly defined. Most of the body surface is affected by periodic, widespread fiery redness of the skin. The erythma (reddening) and exfoliation (shedding) of the skin is accompanied by severe itching and pain. Swelling may also be a symptom.

Erythrodermic Psoriasis

Generalized Pustular

This form is also relatively rare, but forms when widespread areas of reddened skin develop and become acutely painful. Pustules (blisters of non-infectious pus), appear on the skin, dry out, and then reappear in repeated cycles lasting several days.

Generalized Pustular

Localized Pustular

Localized pustular psoriasis appears mainly on the hands and feet. It is characterized by pustules in fleshy areas that appear in studded patterns throughout the reddened plaques of skin. The pustules then turn brown and peel from the skin. Another rare form of this type of psoriasis is characterized by lesions on the ends of fingers and sometimes toes. The lesions can be painful and disabling by causing nail deformities which, in severe cases, causes the nails to turn to bone.

Localized Pustular

Skin Cancer

Basal Cell Carcinoma

Basal cell carcinoma is caused in most cases by repetitive sun-damage and sun-exposure. Because of this, it is most often seen on scalp, forehead, face, nose, neck, and back. The cancer appears as a smooth, pearly-shaped lump with small veins snaking around the surface. If left untreated, BCC can eat away at the skin, leaving a patch that looks like rat had been chewing at it. This is known as a “rodent ulcer.” To determine if BCC is present, the doctor will take a biopsy of the suspicious area. The sample is sent to a pathologist who tests it for cancer cells. Treatments are surgically removing the diseased skin, destroying it using liquid nitrogen, electricity, or a laser, and microscopically controlled surgery for cosmetically important areas. This type of cancer rarely spreads.

Basal Cell Carcinoma

*This is a person’s face*

Squamous Cell Carcinoma

SCC appears mainly in people 55 years and older. The disease is believed to be in direct relation with the total accumulation of solar radiation in a person’s lifetime. The growths are most likely found on the forehead, temple, ears, neck, shoulders, and legs. It begins as a precancerous growth that slowly develops into a firm, small, irritated lump. As the lump grows, it begins to break down and ulcerate. The cancerous area bleeds easily when scraped, but is associated with little to no pain. Treatment begins the same way as BCC treatment, but surgical removal of the cancerous growth is the only course of treatment. Because SCC is likely to spread, all of the cancerous tissue must be removed.

Squamous Cell Carcinoma

Malignant Melanoma

Malignant melanoma is on the rise in the U.S. In fact, it’s increasing by 4-8% every year. One in every one hundred Americans will develop this cancer. Much of this rise is contributed to society’s obsession with tan skin. This form of skin cancer is the most likely to metastasize, or spread through the bloodstream to other areas of the body. Melanoma typically starts with a tan spot that slowly grows and changes.

Melanoma Continued...

Another type is called “nodular” melanoma which develops into a black, blue, or white mark that rapidly grows into a bump/mole. Because melanoma spreads so quickly, early diagnosis and removal of suspicious moles is very important. Once it spreads, malignant melanoma is very difficult to treat. Studies are being done to see if chemotherapies are an effective treatment. As of now, there are no great treatments for malignant melanoma. There are four general types of malignant melanoma.

Superficial Spreading Melanoma

This is the most common type of melanoma, accounting for 65% of a diagnosed cases. It begins at one focus in the skin in the junction of the dermo-epideraml layers. It starts growing on a horizontal plane just above and below the dermo-epidermal junction. This is called the “radial” growth phase. The mole that results from such a growth violates the rules of color, border, elevation, asymmetry, and diameter.

Superficial

Nodular Melanoma

This form of the disease is much less common, and grows in thickness rather than diameter. The outlook worsens as the mole thickens. This form of melanoma metastasizes easily and violates color, diameter, and elevation.

Nodular Melanoma

Lentigo Maligna Melanoma

This form is seen mainly in the older population. It may grow for years horizontally before the more aggressive vertical growth stage begins. This type violates asymmetry, border, color, diameter, and eventually elevation.

Lentigo Maligna Melanoma

Acrolentiginous Melanoma

This type of melanoma appears mainly on the hands and feet. Because of this, it is usually ignored by the patient, and then spreads throughout the body. Color, diameter, border, and asymmetry are all indications.

Acrolentiginous Melanoma