Chapter 21: Microbial Diseases of the Skin and Eyes
Below you will find answers to the "Review" study questions found at the end of this chapter in Microbiology: An Introduction, 7th edition.
- Bacteria usually enter through inapparent openings in the skin. Fungal pathogens (except subcutaneous) often grow on the skin itself. Viral infections of the skin (except warts and herpes simplex) most often gain access to the body through the respiratory tract.
- Staphylococcus aureus; Streptococcus pyogenes.
Impetigo / Staphylococcus aureus / Vesicles that rupture and crust over / Hexachlorophene / May be epidemic
Erysipelas / Streptococcus pyogenes / Thickened red patches, swollen at margins / Penicillin / May be endogenous
Disease / Etiological Agent / Clinical Symptoms / Method of Transmission
Acne / P. acnes / Infected oil glands / Direct contact
Pimples / S. aureus / Infected hair follicles / Direct contact
Warts / Papovavirus / Benign tumor / Direct contact
Chickenpox / Herpesvirus / Vesicular rash / Respiratory route
Fever blisters / Herpesvirus / Recurrent "blisters" / Direct contact
Measles / Paramyxovirus / Papular rash, Koplik's spots / Respiratory route
Rubella / Togavirus / Macular rash / Respiratory route
- Both are fungal infections. Sporotrichosis is a subcutaneous mycosis; athlete's foot is a cutaneous mycosis.
- Conjunctivitis is an inflammation of the conjunctiva, and keratitis is an inflammation of the cornea.
- See pp. 595-597.
- Candidiasis is caused by Candida albicans. The yeast is able to grow when the normal microbiota are suppressed or when the immune system is suppressed. The yeast can be transferred from another person or be transient microbiota. White patches in the mouth or bright red areas of the skin and mucous membranes are signs of infection. Antifungal agents such as miconazole are used to treat candidiasis. Systemic infections are treated with oral ketoconazole.
- The test determines the woman's susceptibility to rubella. If the test is negative, she is susceptible to the disease. If she acquires the disease during pregnancy the fetus could become infected. A susceptible woman should be vaccinated.
Koplik's spots / Measles
Macular rash / Measles
Vesicular rash / Chickenpox
Small, spotted rash / German measles
"Blisters" / Cold sore
Corneal ulcer / Keratoconjunctivitis
- The central nervous system can be invaded following keratoconjunctivitis; this results in encephalitis.
- Attenuated measles, mumps, and rubella viruses.
- Varicella-zoster virus appears to remain latent in nerve cells following recovery from a childhood infection of chickenpox. Later, the virus may be activated and cause a vesicular rash (shingles) in the area of the nerve.
- To prevent neonatal gonorrheal ophthalmia. This is caused by N. gonorrhoeae contracted by the newborn during passage through the birth canal.
- Trachoma.
- Scabies is an infestation of mites in the skin. It is treated with permethrin insecticide or gamma benzene hexachloride.
Below you will find answers to the "Multiple-Choice" study questions found at the end of this chapter in Microbiology: An Introduction, 7th edition.
- c
- d
- b
- c
- d
- d
- e
- d
- a
- d