Chapter 21: Microbial Diseases of the Skin and Eyes

Question 1

Pseudomonas

Answer 1

1. Dermatitis - rash
   - eg. from water (pool)
2. Otitis externa.
   - eg. natural water
3. Opportunistic
   a. post-burn (pseudomonas aeruginosa, blue green pus)
   b. Immunosuppressed (cancer)
   c. cystic fibrosis - lungs infected. takes longer to get rid of

Question 2

Human Papilloma Virus - Warts

Answer 2

• 50 types of HPV
• can be spread by
  1. contact (fomites, like clothes, furniture, and sexual contact)
  2. shower floor
• epidermis infecton
• different types of warts
• nipple like protrusion
• treatment

Question 3

HSV-1

Answer 3

• cold sores
• oral or respiratory
• recurrent
• transmitted by oral sex
• latent / hiding in the trigeminal nerve (cranial V)
• can cause infections in fingers of medical personnel (herpetic whitlow)

Question 4

HSV-2

Answer 4

• genital herpes
• transmitted through sexual contact, oral sex
• reoccurring
• hide / latency
• sacral nerve (lower back)
• treatment available
• can cause brain encephalitis

Question 5

HSV-3

Answer 5

• chicken pox / shingles / varicella zoster
• as a crop: macule, papule, vesicle (fluid), pustule
• crust over
• secondary infection
• immunications
• dorsal root - ganglion

zoster form

• painful
• weeks - months
• acyclovir
• vaccine for ~50 years old

Question 6

Measles - Virus

Answer 6

1. Rubeola (red)
   - spotted macular red rash
   - cold symptoms (running nose, fever)
   - koplik’s spots: oral cavity is filled with white spots. affects the oral mucosa
   - pregnant women may have miscarriages, stillbirths, or low birth weight
2. Rubella (german)
   - 3 days
   - pink rash
   - no koplik’s spots
   - congenital: causes mental defects, cataracts

Question 7

Conjunctiva

Answer 7

• red, swollen, teary, sensitive, pus

- microbial disease of the eye

Question 8

Trachoma

Answer 8

• microbial disease of the eye
  1. conjunctivitis
  2. eyelid
  3. trichiasis - abrasion
  4. leading cause of blindness
  5. treated by tetracycline, erythromycin
• caused by chlamydia, trachomatis

Question 9

Staphylococcus aureus

Answer 9

1. Direct Invasion
   - folliculitis: infections of the hair follicles
   - red, swollen, pain, pus
   - carbuncle:
   - pus, systemic
   - surgical removal, antibiotics
2. Staphylococcal Scalded Skin Syndrome (SSSS)
   - more susceptible in children and elderly
   a. red skin, 20-100%
   b. genitalia, red and rash
   c. skin ~ 48-72 hours
   - forms blisters that fill with fluid
   - exfoliative exotoxin: breaks up ester bonds. causes skin to peel off
   d. skin is scalded in sheets
   e. secondary infetions
   - strep, pneumonia
3. Impetigo (newborn)
   - a pyoderma (skin infection with pus) of the epidermis
   - inflammation in the lymph nodes “yellowish crust / crusting sores”

Question 10

Toxic Shock Syndrome (TSS)

Answer 10

• occurs in women with tampon use because a full tampon is a nutrient rich environment for exotoxins, the tampon material could abrade the vagina during insertion and leads to the depletion of the Mg+ ion.
  after childbirth and after surgery
• also occurs after childbirth and surgery

symptoms

• fever
• headaches
• confusion (CNS)
• sunburn rash
• nausea, diarrhea
• kidneys
• shock

precautions (tampon)

• abraision
• handwashing before and after insertion
• absorbency level
• changing tampons regularly
• avoiding them during the night

Question 11

Streptococcus pyogenes - M protein

Answer 11

• group A B-hemolytic streptococcus
  1. Erysipelas
• located in the dermis, reddish patches with raised margins
• inflammation (septicemia)
• treat with penicillin, cephalosporin

2. Direct Invasion
   - necrotizing fasciitis (50% mortality)
   a. enter
   b, collagenase, hyaluronidase
   c. spreads to affect organs and cause organ failure
   d. amputation
   - only party effective, it could have still spread to other parts of the body