Skin and Soft Tissue Exam 4 Review

How does skin act as the first line of defense against microbial invasions?

• removes substances from surface

• colonization of resident flora

Which layer of the skin is keratin found in?

Epidermis (Stratum Corneum) - epithelial cells and keratin

Which group of fungi attacks keratin?

Dermatophytes

Which layer of skin tissue is composed of connective tissue and contains sweat glands, hair follicles, and oil glands?

Dermis

What is Fascia?

Thin bands of connective tissue below the dermis and above the muscle

What is the purpose of hyaluronic acid, and where is it found?

It is a lubricant that is in all layers of the skin

What is the difference between sebum and perspiration?

Sebum: Oily substance produced in sebaceous glands and contains lysosomes

Perspiration: Water substance containing salt produced by sweat glands

How does normal skin flora help protect us?

• Creates a competitive environment to inhibit pathogens

• Ability to adapt to high salt, exposure to elements, acidic pH, and lack of nutrients

What are the major ways we classify skin infections?

By the appearance of lesions and the manifestation (Systemic, primary, structures infections, and organisms)

What is a pustule?

A raised lesion with pus, including fluid and WBC

What is a vesicle?

A blister

What is a macule?

Flat discoloration of skin

What is a papule?

Elevated solid lesion

What is dermatitis?

Broad term for inflammation of the outer layers of skin

What are the 4 main categories of Dermatitis?

Intertrigo, Thrush, Erythrasma, Dermatophytosis

What is Intertrigo?

Skin folds due to obesity, diabetes, and extreme ages

What is Thrush?

Yeast infection the oral mucosa

What is Erythrasma?

Macules in the keratinized layer of epidermis

What is Dermatophytosis?

Fungal infection in the keratinized layer of skin

What is pyoderma?

Broad term for skin infections containing pus

What are most Pyodermas caused by?

So. pyogenes and S. aureus

Pyoderma - Impetigo

Erythematous, painless, small vesicles that rupture

Pyoderma - Erysipelas

Superficial cellulites involving the epidermis, dermis, and lymphatic

Pyoderma - Erysipeloid

Superficial soft tissue infection caused by Erysipelothrix rhysiopathiae

Pyoderma - Anthrax

Cutaneous ulcerative disease starts as a lesion to papule to blister to eschar (Anthraxis Bacillus)

Pyoderma - Cellulitis

Diffuse Infection involving deep layers of dermis. Painful, warm to touch, with edema and pus drainage

Pyoderma - Paronychia

Infection of the cuticle around the nail bed

Pyoderma - Folliculitis

Inflammation of hair follicles

Pyoderma - Furuncles

Painful, pus filled boiled typically caused by S. aureus

Pyoderma - Carbuncles

a series of furuncles that coalesce and spread deeper into dermis and subcutaneous tissue

Pyoderma - Hidradenitis suppurativa

Recurrent infection of the apocrine sweat glands

Soft Tissue Infection - Human Bites causes

Eikenella corrodens (“will eek if a person bite me”)

Soft tissue infection - animal bites

Pasteurella multocida (“pastures”)

Soft Tissue infection - Diabetic Foot Ulcers

Cellulitis to soft tissue ulcerate to gas gangrene

Soft Tissue Infection - necrotizing fasciitis

Fast moving and life threatening

What organism causes both Necrotizing fasciitis and Diabetic Foot ulcers?

C. perfringens

Mycetoma

Painful swelling, sinus tracts, with a discharge

What is Eumycetoma?

Mycetoma caused by Fungi - Madurella and Aspergillus

What is Actinomycetoma?

Mycetoma caused by bacteria - Nocardia and Actinomyces

Fungal Soft Tissue - Chromomycosis

Localized, scaly lesions, from minor trauma (Phialophora, Cladophialophora)

Fungal Soft Tissue - Mucormycosis

Localized cutaneous infection that can disseminate to the brain (Mucor)

What is nodular lymphangitis?

Lymphocutaneous syndrome: Inflammatory nodules along the lymphatic system

What three organisms cause Lymphocutaneous syndrome?

Sporothrix schenckii, Nocardia, Mycobacteria

What is SSSS?

Staphylococcal Scaled Skin Syndrome

What causes SSSS?

Caused by exotoxin producing S. aureus

What is a clinical sign that is indicative in SSSS cases?

Nikolsky Sign: Separation of skin just by touch when the blisters rupture

What is TSST-1?

Toxic Shock Syndrome Toxin 1 - caused by S. aureus

What is SPE?

Streptococcal Pyrogenic Exotoxin - Streptococcus pyogenes

What is Scarlet fever?

It is SPE after a Strep throat infection - Strawberry tongue

What virus produces Koplik’s spots?

Measles - red patches with central grey specs in the buccal mucosa

Which virus produces a bright red rash that resembles a “slapped” face?

Parvovirus - B19 or 5th disease

Describe the rash produced by the Variola Zoster virus?

Chicken Pox/Shingles

Which virus is noted for cauliflower like papilloma?

Human Papillomaviruses (HPV)

Which virus is associated with Kaposi Sarcoma?

Human Herpesvirus 8 - is an AIDS defining disease

What parasites are associated with skin infections and why?

Schistomes - blood trematodes

Leishamania - Blood and tissue flagellates

Hooksworms

Microfilariae

Guinea worm