A
What cells comprise most of the epidermis?
Keratinocytes
What layer of skin is located below the epidermis?
Dermis
What is the etiological agent of otitis externa?
P. aeruginosa
What is the etiological agent of protozoan keratitis?
Acanthamoeba
What etiological agent can cause impetigo, erysipelas, cellulitis, and folliculitis?
S. pyogenes
What is the leading cause of preventable microbial blindness worldwide?
Trachoma
What are cutaneous mycoses?
Fungal skin infections
What is the etiological agent of smallpox? Before eradication, why was smallpox one of the most feared diseases?
Variola major virus
What layer associated with the skin is located below the dermis?
Subcutaneous layer
What is the etiological agent of gas gangrene?
Clostridium perfringens
“Staph infections” are mainly caused by which bacterium?
Staphylococcus aureus
Reactivation of which dormant pathogen causes shingles?
Varicella-zoster viruses
What is dermatoses?
Infections and noninfectious skin diseases
What 2 organisms are the most common cause of bacterial keratitis?
Pseudomonas aeruginosa & Staphylococcus aureus
What is the etiological agent that causes many cutaneous mycoses, such a diaper rash?
Candida albicans
What is the etiological agent of chickenpox?
Herpesviridae family virus varicella-zoster
What type of organism causes ringworm?
Fungus species
What is the etiological agent of most herpetic keratitis infections?
Herpes simplex 1 virus
Which individuals are at highest risk for fungal keratitis?
Individuals that have suffered eye trauma or have had eye surgery (including radial keratotomy to correct nearsightedness)
How is helminthic keratitis introduced into humans? What nerve and/or eye structure is damaged by this pathogen?
When an infected blackfly bites someone and introduces Onchocerca volvulus larvae to the skin
What are the main 3 fungal genera that cause most tinea infections?
Trichophyton, Microsporum, and Epidermophyton fungus species
What is dermatophyte?
A collection of fungal organisms that cause conditions of the skin, hair, or nails
What is the conjunctiva?
The epithelial membrane that covers the eyeball and lines the eyelids
What is lesion? What is the difference between a primary and secondary lesion?
Lesion is the clinical term for any observable abnormality of the skin
Primary lesions are directly associated with a disease and are considered key features for diagnosing a variety of infections
Secondary lesions are less strictly defined and have diverse origins
Which two bacteria cause neonatal bacterial conjunctivitis and how is it acquired?
Neisseria gonorrhoeae or Chlamydia trachomatis, and is acquired by vertical transmission at birth
What clinical features can distinguish bacterial vs. viral conjunctivitis?
The nature of the fluid discharge from the eye, A puslike discharge (often green or yellow) is usually associated with bacterial eye infections.
Most viral conjunctivitis is accompanied by a watery discharge
What is cellulitis?
A deeper Staphylococcus aureus infection of the lower dermal and subcutaneous fat; mainly seen in adults and is characterized by red, swollen, and painful skin; may be accompanied by fever, leukocytosis, and/or lymphangitis (inflamed lymphatic vessels)
What is sebum?
An oily or waxy substance produced by the skin’s sebaceous glands (oil glands) and is a combination of low-pH lipids and proteins that moisturize and further protect the skin
What are the differences between cutaneous, mucocutaneous, and visceral leishmaniasis?
Cutaneous leishmaniasis - A protozoan infection caused by Leishmania in which skin ulcers, which are usually painless, form at bite sites and can persist for months or even years
Mucocutaneous leishmaniasis - A protozoan infection caused by Leishmania in which the lesions develop in mucous membranes of the nose or mouth; it can lead to severe and permanent disfigurement as the protozoan destroys these structures
Visceral leishmaniasis - A protozoan infection caused by Leishmania in which the protozoan spreads throughout the body; according to the World Health Organization, in developing countries where proper treatment is difficult, visceral leishmaniasis is usually fatal within two years