Skin Disorders & Neoplasms

Question 1

Which skin disorders are caused by bacteria?

Answer 1

Acne (propionibacterium), Impetigo (staph and strept bacteria).

Question 2

Which skin disorders are autoimmune diseases? What does this mean?

Answer 2

In autoimmune diseases, white blood cells (WBCs) attack and destroy normal body
substances they should leave alone. (The reason this happens is often unknown.)
Scleroderma is an autoimmune disease where white blood cells attack collagen in the
skin, producing hardened, yellowish scar tissue. Vitiligo is an autoimmune disease
where white blood cells attack the melanocytes of the skin. A gradual bleaching of the
skin occurs (white patches appear & spread) because the melanocytes stop making
melanin. Psoriasis is also an autoimmune disease, although what the WBCs are
attacking is not clear.

Question 3

What are mycoses caused by? Give an example.

Answer 3

Fungal infections of the skin. Also known as tinea. Jock itch, Athlete’s foot, and vaginal
yeast infections are examples.

Question 4

Which skin disorder is due to ischemia in the tissue?

Answer 4

Ischemia means reduced blood flow to a tissue. If ischemia is severe enough it causes
bedsores, or decubitus ulcers, because the tissue dies and rots away

Question 5

Which skin disorder is characterized by excessive mitosis and hyperkeratosis?

Answer 5

Psoriasis. Hyperkeratosis means that excess keratin is deposited in the skin.

Question 6

Both psoriasis and seborrheic dermatitis involve scaling of the skin, but how
does the cause of the scaling differ between the two disorders?

Answer 6

The scaling that occurs with psoriasis occurs when the skin cells divide too rapidly
(excessive mitosis). The scales are very large and silver in color, commonly occurring
on the elbows and knees, and sometimes on the scalp. Excess keratin is also deposited
in the skin (hyperkeratosis). Psoriasis is considered an autoimmune disorder although
it is still poorly understood.
With seborrhea the scaling that occurs is caused by overactive oil glands. The excess
oil produced may be due to irritation of the oil glands but so far the cause is still unknown
(idiopathic). The scaling is most often on the scalp, but may also be on the face and
chest. Seborrhea can be considered a severe form of dandruff.

Question 7

What is a benign tumor of the skin capillaries?

Answer 7

A birthmark or hemangioma

Question 8

Describe the symptoms and possible causes of rosacea.

Answer 8

Rosacea is characterized by repeated flushing of blood vessels of the nose and
surrounding area. It is a vascular inflammatory disorder where blood vessels and oil
gland become inflamed for long periods of time. The cause of rosacea is unknown.
The tissue becomes chronically inflamed, with development of spider veins (due to blood
congestion in veins) and growth of new tissue that enlarges the nose (rhinophyma).
Flaking of the skin is also common.

Question 9

Which skin disorder is characterized by weeping bumps and blisters and often
associated with allergies?

Answer 9

Eczema is often linked to allergies and asthma.

Question 10

What is acne caused by?

Answer 10

Acne is caused by two things: 1) overproductive oil glands that become infected with
2) a specific bacterium, propionibacterium. The bacteria live in the oil glands and
feeds on the oil, causing inflammation in the gland—the pimple.