176 Week 9 Day 2 Notes Infection/Tissue Integrity

Skin as the Largest Organ

The skin is the body's largest organ, acting as a barrier.
It keeps outside elements out and inside elements in.
Composed of the dermis and epidermis layers.
Subcutaneous tissue contains fat, used for subcutaneous injections.
Mucous membranes are also barriers but are more vulnerable. Some have mucus to flush out bacteria.

Body Defenses Against Infection

The body has various defenses against infection.
Nursing assistants can apply over-the-counter lotion on intact skin and assist with turning patients and giving blankets.
They cannot cover a draining wound with treatments or assess it but can contain the drainage to notify the nurse.
They cannot assess itching rashes but can observe and report to the nurse.

Infection and the Iceberg Concept

Infection occurs when bacteria invade tissue and multiply.
The iceberg concept illustrates infection distribution:
- Most of the iceberg (underwater): asymptomatic carriers. (e.g., people with COVID who had no symptoms but could spread it.)
- Middle portion (above water): infected but not severely ill (e.g., flu patients who rest and recover at home).
- Tip of the iceberg: people with classical, severe symptoms of the disease.

Normal Flora and MRSA

The body is covered in bacteria and fungi, part of our normal flora.
Example: Healthcare workers often carry MRSA in their noses, kept under control by the immune system.

Infection Control and Handwashing

Alcohol-based hand sanitizer is less effective on visibly soiled hands.
Soap and water should be used to remove stickiness from sanitizer residue.
Certain infections like C. Diff are not killed by alcohol; mechanical washing with soap and water is necessary to remove spores.

Oral Thrush (Candidiasis)

White patches on mucous membranes that, when swabbed, reveal raw skin underneath are likely thrush.
Characterized by a white overcast; when swabbed off, the underlying tissue is red and raw.
Common in babies, people on high doses of antibiotics, and immunocompromised individuals.
Thrush in a healthy adult indicates an underlying issue.

Chain of Infection

The key to infection control is breaking the chain of infection.
Examples of interrupting the chain:
- Portal of exit: use masks for coughing/sneezing patients.
- Port of entry: use masks for susceptible individuals.
- Reservoirs include door handles, stagnant water, and healthcare equipment.
Portals of exit: urine, feces, saliva, blood, skin, GI tract.
Portals of entry: broken skin, sexual contact, mouth, respiratory tract, GI tract, contaminated food/water.

Viral Disorders of the Skin: Herpes Simplex and Herpes Zoster

Herpes Simplex

Two types: type 1 (oral) and type 2 (genital), though either can occur in either location.
Many people are exposed to type 1, often in childhood.
Diagnosis can be made by swabbing a lesion.
Symptoms start with pain, itching, burning, or tingling, followed by fluid-filled vesicles that rupture and crust over.
The virus remains in the body, with outbreaks triggered by immune system compromise.
Initial outbreaks are typically the worst.
Type 1 is usually transmitted through oral secretions; type 2 through sexual contact.
Cold sores/fever blisters are common manifestations.
In newborns, herpes simplex can be severe; hence, advising against kissing babies with cold sores.
Treatment aims to shorten outbreaks and reduce misery, starting within 1-2 days of outbreak.
Antiviral drugs (suffix: "-cyclovir") are used.
- Example: acyclovir.
Over-the-counter treatment: Abreva.
Severe cases may require PO, topical, or IV acyclovir.
Frequent outbreaks may warrant daily suppressive therapy with Valtrex (valacyclovir), taken daily to prevent outbreaks.

Herpes Zoster (Shingles)

Caused by the same virus as chickenpox (varicella zoster).
Occurs when the virus, dormant in a nerve, reactivates due to immune system suppression.
Individuals who have not had chickenpox or the vaccine can contract chickenpox from someone with shingles.
Risk factors include immunosuppressive therapy, chemotherapy, being young or old, stress, and age over 50.
Complications include postherpetic neuralgia (persistent nerve pain), trigeminal herpes zoster (affecting facial nerves and potentially causing hearing loss), and ophthalmic involvement (affecting the eyes).
Symptoms: pain/tingling followed by a rash, typically unilateral and following a nerve tract.
Infectious while the rash is moist (7-10 days).
Diagnosis: clinical assessment or Tzanck test (swab fluid from blister).
Management: shorten duration and reduce misery using antivirals (acyclovir, famciclovir, valacyclovir).
Start treatment within three days of outbreak.
Burrow's solution (aluminum acetate) can be used as a compress to loosen crusts and soothe skin.
Pain control: gabapentin (for nerve pain), topical pain relief, corticosteroids (inflammation and itching).
Vaccine: Shingrix, recommended for adults 50+ and those 19+ with weakened immune systems.
Capsaicin cream may be used for pain (educate patients on handwashing).
Isolation: standard precautions if localized and covered with a working immune system; airborne contact if weakened immune system or disseminated rash.

Postherpetic Neuralgia and Other Complications

Can cause long-term pain, eye complications, encephalitis, trigeminal neuralgia, and facial nerve problems.
Treatments include analgesics, anticonvulsants (gabapentin), antidepressants, anti-inflammatories, anesthetics, TENS units, nerve blocks, and acupuncture.

General Bacterial Disorders of the Skin: Cellulitis

Gram-positive bacteria can produce exotoxins; gram-negative bacteria (like C. Diff) produce endotoxins.
Cellulitis is a common infection affecting the epidermis, dermis, and subcutaneous layers (especially in diabetics).
Caused by Streptococcus or Staphylococcus aureus, often via skin wounds or ulcers.
Commonly located in lower extremities, associated with chronic venous insufficiency and stasis dermatitis.
Bacteria create enzymes causing severe inflammation, resulting in diffuse borders, warmth, sensitivity, redness, and swelling.
Systemic symptoms: fever, malaise, and chills.
Erysipelas is a type of cellulitis primarily affecting the dermis and epidermis, caused by Group A Streptococcus.
Presents as firm red spots merging into defined, bright red, hot lesions with a raised border; vesicles may develop.
Symptoms: itching, burning, and tenderness.
Common on the face and lower extremities, especially in infants, young children, older adults, and immunocompromised individuals.
Other types: orbital cellulitis (around the eye) and necrotizing cellulitis (rare, life-threatening).
Necrotizing cellulitis risk factors: immunocompromised, diabetic, peripheral artery disease; can lead to sepsis, shock, and organ failure.
Treatment: moist heat, immobilization, elevation, and systemic antibiotics (culture before administration).
Nursing interventions: promote rest, warm compresses, antibacterial dressings, ointments, or gels.
Complications: gangrene and sepsis (can be fatal).
Symptoms of cellulitis: redness, warmth, swelling, and pain.
Risk factors: poor hygiene and Diabetes.
Treatment: antibiotics (penicillin, cephalexin, rifampin, or vancomycin).
Always use warm compresses to increase blood flow.
Obtain a culture before administering antibiotics unless it delays care.

Buggies: Lice (Pediculosis) and Scabies

Lice (Pediculosis)

Medical term for lice: pediculosis.
Human lice are species-specific and require contact for transmission (they don't fly or jump).
Adults can survive 48 hours without blood.
Nits (eggs) take 7-10 days to hatch, with 2 more days for the nymph to mature into an adult.
Items that cannot be treated should be sealed in plastic for 14 days.
Three types: pediculosis capitis (head lice), pediculosis corporis (body lice), and pediculosis pubis (pubic lice).
Easier to spot in dark hair.
Nits are glued to the hair shaft.
Adults are hard to see because they run.
Check around the ears and nape of the neck.
Treatment: permethrin cream rinse (over-the-counter or prescription).
- Apply after washing hair, comb through, leave on for 10 minutes, then rinse.
Nitpicking: use a nit comb daily.
For infants and pregnant women, use occlusive agents like petroleum jelly.
Identify and assess family members.
Educate on how to eliminate lice: use nit combs, discard or soak hair products in boiling water, wash clothing and linens in hot water and dry on high heat, and seal non-washable items in plastic for two weeks.

Scabies

Microscopic human itch mite that burrows into the skin to live and lay eggs.
Transmitted person-to-person or via infected sheets/clothing.
Adult mites can live on objects for two days.
Incubation: eggs hatch in 3-5 days, adults live for 4-5 weeks.
Diagnosis: skin scrapings examined under a microscope.
Mites prefer warm areas with good blood supply and protection, such as between fingers and skin folds.
May see wavy, brown, thread-like lines (burrows).
Itching is worse at night.
Treatment: permethrin cream applied to cool, dry skin at least 30 minutes after bathing.
- Massage thoroughly onto all skin surfaces from head to soles of feet (avoiding the eyes), leave on for 8-14 hours, then rinse.
Teach frequent handwashing, keep nails short and clean, and treat family members.
Wash everything in hot water and dry on high heat.
Vacuum bags of chairs and sofas, and remove the vacuum contents from the house.

Fungal Infections of the Skin

Fungi can be single-celled yeasts or colonies of molds or mushrooms.
Fungi that cause disease are called fungi imperfecti.
Most healthy individuals' immune systems eliminate fungus.
Some fungi can be fatal to immunosuppressed individuals.
Examples: ringworm, athlete's foot, jock itch.
Superficial infection of the skin; fungus feeds on dead skin cells, preferring warm, moist, dark areas.
Spread by direct contact or surfaces.
Candidiasis (yeast infection) is common with antibiotic use.
Risk factors: diabetes, immunosuppressive therapy, pregnancy.
Commonly seen in the mouth, vagina, or skin; watch ostomy sites.
Tinea corporis (ringworm on the body): ring-shaped rash with a smooth center.
Tinea pedis (athlete's foot): macerated, moist skin with fissures, vesicles, and cracks; may itch, burn, and discolor.
Treatment: topical (Lotrimin, nystatin, miconazole) or oral antifungals.
Requires consistent treatment for the full duration (2-6 weeks) to eliminate effectively.
Tinea corporis treatment: athletes should shower after practice and avoid sharing equipment.
Key to preventing and treating tinea pedis is airflow and keeping feet dry.

Skin Cancers: Nonmelanomas and Melanoma

Abnormal nevi is typical and common.
Nonmelanomas: basal cell carcinoma (pearly or waxy appearance) and squamous cell carcinoma (crusty and scaly).
Melanoma: the most dangerous. It can appear anywhere (not just sun-exposed areas).
Risk factors: sun exposure, lack of pigment (pale skin, freckles, light hair/eyes), male gender, smoking, drinking, tanning beds with sunburns.

Basal Cell Carcinoma

Most common skin cancer.
Slow-growing, rarely metastasizes.
Causes tissue damage.
Treated with Mohs micrographic excision (surgeon removes lesion, microbiologist examines edges to ensure all cancer cells are removed).

Squamous Cell Carcinoma

Ulcerated, scaly appearance.
Associated with smoking and alcohol use.
Grows fast and is metastatic.
Treated aggressively with Mohs micrographic excision.

Treatments for Both

Surgical excision.
Cryotherapy (freezing).
Radiation therapy.
Injected drugs.