BIO 2730 Chapter 22 - Skin Diseases

Abscess

Localized collection of pus surrounded by inflamed tissue

Sebaceous gland

oil-secreting gland in the dermis that is associated with hair follicles

Hair Follicle infections

Signs/Symptoms: usually mild, but can become serious or blood bourne
Pathogenesis: minor infections of hair follicles can be relieved by pulling the hair and releasing the pus; more advanced infections produce a necrotic plug, a minor epidermal lesion, an

Exfoliatin

a bacterial toxin that causes sloughing of the outer epidermis

Staphlococcal Scalded Skin Syndrome (SSSS)

Causative agent: S. aureus with exfoliatin toxin gene, 5%
Signs/Symptoms: the skin wrinkles and appears scalded or burned, feels like sandpaper and starts peeling
Pathogenesis: small infection; toxin distributes systemically, causing the epidermis and der

Pyoderma

any acute, inflammatory, pus-forming bacterial skin infection such as impetigo

Impetigo

Causative agent: Streptococcus pyogenes (bacteria)
Signs/Symptoms: blisters that break, releasing plasma and pus; formation of golden crusts
Epidemiology: direct contact transmission with carriers or the infected insects, or fomites

Rocky Mountain Spotted Fever

Signs/Symptoms: headache; fever, pain in muscles and joints; followed by hemorrhagic rash of the extremities
Epidemiology: zoonotic; carried by insect vector (wood tick) from deer
Treatment: antibiotics. Prevention: tick avoidance - insect repellant, tick

Chickenpox

Signs/Symptoms: itchy bumps and blisters (pustules) that form, break and spread; fever; latent infections can reactivate, resulting in shingles
Epidemiology: highly infectious via skin pus/lesions or respiratory secretions. Human reservoir - people with a

Macules

flat, reddened lesions

Papules

Firm raised areas such as pimples and the eruptions seen in some stages of chickenpox and syphilis.

Koplik Spots

small, blue-white spots with red halo over oral mucosa; early sign of measles

Rebeola (measles)

Signs/Symptoms: rash, fever, weepy eyes, bad cough, and rhinitis. Rare, sometimes fatal complication of encephalitis
Epidemiology: droplet and respiratory secretion transmission; highly contagious; humans only
Treatment: no treatment. Very Effective vacci

Rubella (German Measles)

Signs/Symptoms: mild fever and cold-like symptoms, "T" rash beginning on forehead and face, enlarged lymph nodes behind the ears
Pathogenesis: Respiratory tract replication; spreads throughout the body and may cross the placental barrier; frequent spontan

Superficial Cutaneous Mycoses (athlete's foot, jock itch, ringworm)

Signs/Symptoms: most have no symptoms; some complain of itching, bad odor or rash. Ringworm can produce a scaly area surrounded by a reddened ring. This group also includes dandruff, beard itch, nail fungus, etc
Pathogenesis: normal skin is generally resi

Pustules

itchy bumps and blisters

Folliculitis

inflammation of the hair follicles

Carbuncle

multiple follicles

Tinea Versicolor

a fungal infection that causes painless, discolored areas on the skin
Malassezia furfur yeast and filamentous forms

Candida albicans

yeast infection
C. albicans yeast forms and filamentous forms called pseudohyphae

Vesicles

small blisters

The average person sheds about 40,000 skin cells daily or 1,500 during a typical microbiology lecture.

True

Individuals colonized with S. aureus may have as many as 100,000,000 (108) cells of the bacterium per nostril.

True

Non-immune people can contract chickenpox from someone with shingles.

True

Know which tick-borne bacterial infection produces which infection, and which is local to us.

- Black-legged Tick
o Lyme Disease
o Eastern and Northern-Central US
- Wood Tick
o Rocky Mountain Spotted Fever
o Western US

Know the two conditions that Malassezia furfur produces

- Tinea Versicolor
- Candida albicans