Dermatology Exam Notes

Diagnostic Tests

  • Tzanck Test:

    • Procedure: To perform a Tzanck test, wash the lesion, open the lesion with a hypodermic needle, saturate a sterile swab with exudates, place the specimen in a culture tube, and take it to the laboratory.

    • Purpose: This test is used for viral culture, particularly when a physician asks for a smear from herpetic lesions.

    • Diagnosis: A diagnosis of herpes zoster infection can be confirmed by a Tzanck test or a viral culture of material from a lesion, in conjunction with health history and physical examination findings.

Phototherapy

  • Definition: Phototherapy utilizes ultraviolet light (UVA to UVB), sometimes combined with photosensitive drugs (PUVA), to slow skin cell turnover and improve chronic skin conditions. It promotes shedding of the epidermis.

  • Indications: Phototherapy is used to treat psoriasis, vitiligo, and chronic eczema.

  • Contraindications: It is NOT used for HIV, skin cancer, cataracts, or lupus erythematosus, despite a plastic surgeon potentially considering it for lupus erythematosus.

  • Patient Information/Nursing Interventions:

    • Always wear protective goggles during treatment.

    • Cover or shield unaffected areas to prevent burns.

    • Apply moisturizer after the session.

    • Avoid additional sun exposure.

    • Patients with vitiligo receiving phototherapy should wear protective clothing, sunscreen, and dark glasses.

  • Tanning Beds: Tanning beds have been specifically labeled carcinogenic to humans. The risk of melanoma increases by 75\% among people who begin using them before age 30 years, as well as with the severity of a burn.

Skin Cancer: Malignant Melanoma

  • Causes: The most common cause of skin cancer is sun exposure. Other causes include fair skin with freckling, light-colored hair and eyes, male gender, cigarette smoking, tanning beds, and a tendency to sunburn easily.

  • Signs, Symptoms, and Characteristics:

    • Lesions may begin as a tan macule that enlarges and becomes either very dark or light in color.

    • Typical melanomas have irregular borders and uneven coloration (e.g., purplish, irregular color).

    • ABCDE Rule: This rule helps identify characteristics suspicious of melanoma:

      • A = Asymmetry: One half unlike the other.

      • B = Border: Irregular, ragged, notched.

      • C = Color: Varied shades or uneven coloration.

      • D = Diameter: Usually > 6 mm.

      • E = Evolving: Lesion is changing in size, shape, color, or other characteristics.

Atopic Dermatitis (Eczema)

  • Nursing Interventions:

    • Inquire about known allergies, bathing practices (frequency, water temperature, use of soaps), and current medications to identify possible contributing factors.

    • Complete a physical examination, including inspection and palpation of the skin for lesions, moisture, and abrasions.

    • Use measures that decrease itching and moisturize the skin to maintain tissue integrity.

      • Encourage the patient to keep room temperature at 68-75^[\circ] F with 45\%-55\% humidity.

    • New clothing should be washed with mild detergent before being worn, and clothes should be rinsed twice. Recommend open-weave fabrics and loose clothing.

    • Advise the use of moisturizer and sunscreen; evaluate skin integrity and hydration on an ongoing basis.

    • Emphasize good hygiene and skin care.

    • Teach the patient to correctly apply corticosteroid creams.

    • Avoid irritants such as harsh soaps, detergents, wool clothing, and fragrances.

    • Moisturize frequently using emollients like Eucerin, Cetaphil, or petroleum-based ointment immediately after bathing.

    • Take antihistamines, topical corticosteroids, or immunomodulators exactly as prescribed.

    • Maintain a stable environment: temperature 68 to 75^[\circ] F with 45-55\% humidity.

    • Reduce stress.

    • Teach the patient to cut nails short to minimize damage from scratching.

  • Signs, Symptoms, and Characteristics:

    • Subacute Stage: Characterized by redness, excoriations, and scaling plaques or pustules.

    • Eczema Stages: Eczema has three different stages, which can be present simultaneously:

      • Acute Stage: Characterized by a red, oozing, crusted rash and intense pruritus.

      • Subacute Stage: Characterized by redness, excoriations, and scaling plaques or pustules.

      • Chronic Stage: Skin becomes dry, thickened, scaly, and brownish-gray in color.

    • Affected Areas: The most commonly affected areas include the back of the neck, elbow creases, and the backs of the knees. Other areas include the face, trunk, wrists, and forearms.

    • Open skin from scratching is a common occurrence.

Medications: Acyclovir (Zovirax)

  • Uses: Acyclovir is used to treat herpes simplex infections.

  • Efficacy: Antiviral drugs like acyclovir are not curative but may reduce the severity and frequency of outbreaks.

  • Formulations: Oral acyclovir is generally more effective than the topical preparation for both initial and recurrent infections.

Procedures: Deep Skin Biopsy

  • Post-procedural Care:

    • Inspect the site for bleeding; apply direct pressure if necessary to control bleeding.

    • Instruct the patient to return for suture removal.

    • Provide instructions to the patient on how to care for the biopsy site.

Negative Pressure Therapy

  • Clinical Indications: This therapy is used to reduce healing time for traumatic wounds, dehisced surgical wounds, skin grafts, pressure injuries (pressure ulcers), and chronic ulcers.

Skin Aging and Wrinkling

  • Causes: Wrinkling results from:

    • Decreased collagen and elastin fibers.

    • Thinning of the dermis and epidermis.

    • Sun/UV damage.

    • Moisture loss.

    • Smoking, dehydration, repetitive facial expressions, and genetics.

    • Specifically, thinning of skin layers and degeneration of elastin fibers result in wrinkling.

Herpes Simplex Virus (HSV)

  • Dormancy: HSV lies dormant in nerve clusters and can be triggered without any sexual contact.

  • HSV-1: Typically associated with oral herpes, residing in nerve clusters around the face and upper body.

  • HSV-2: Typically associated with genital herpes, primarily located in the groin/genital area.

Contact Dermatitis

  • Cause: Contact dermatitis is an inflammatory condition caused by direct contact with a substance that triggers an allergic response (e.g., poison oak).

Intertrigo

  • Definition: Intertrigo is an inflammation of the skin where two skin surfaces touch (e.g., axillae, abdominal skinfolds, and the area under the breasts). The affected area is usually red and "weeping" with clear margins, and may be surrounded by vesicles and pustules.

  • Causes: It is a disorder associated with inflammation that occurs between two surfaces, caused by heat, friction, and moisture.

  • Nursing Interventions:

    • Report increasing redness, tenderness, broken skin, and fever to the healthcare provider.

    • Encourage women with pendulous breasts to wear soft, supportive bras.

    • Investigate complaints of pain, irritation, or redness in body folds.

    • Monitor body temperature to detect possible infection.

    • Inspect areas where intertrigo grows (folds, under breasts, groin).

    • Keep these areas clean and dry.

    • Wash with water twice a day, rinse and pat dry, and place dry, soft gauze between two touching surfaces to absorb moisture.

    • Apply topical medications, such as antifungals and corticosteroids, as ordered.

    • Apply lubricant to unbroken skin.

    • Encourage clients to keep nails short and to report excessive scratching.

Strategies to Reduce Scratching

  • Avoiding irritants.

  • Applying lotions or creams and lubricants.

  • Applying topical treatments as ordered (e.g., corticosteroids).

  • Maintaining short fingernails; use gloves or mittens at night.

  • Providing cool, moist compresses or baths.

  • Using mild soaps and avoiding hot water.

  • Administering antihistamines.

  • Encouraging distraction techniques.

  • Educating patients to pat, not scratch, itchy areas.

Herpes Zoster (Shingles)

  • Cause: Shingles occurs when the Herpes Zoster virus is reactivated.

  • Signs and Symptoms:

    • Pain, itching, burning, tingling, or heightened sensitivity along nerve pathways.

    • Red inflamed patches develop into clusters of painful blisters (vesicles) in the affected area.

    • Vesicles often crust over for 7 to 10 days.

    • The pain can be severe, sharp, stabbing, or burning in the affected area.

    • These painful vesicles follow a nerve pathway.

Burn Injuries

  • Airway Compromise Risk: Major burns to the head, neck, and chest pose the greatest risk for airway obstruction.

    • These burns can cause edema of the airway, leading to obstruction.

    • Swelling inside the mouth, neck, and trachea may not appear immediately, but when it does, the airway can rapidly close.

    • There is also a risk of inhalation injury and impaired ventilation.

  • Rule of 9s for Adults (Estimation of Total Body Surface Area Burned):

    • Each arm = 9\%

    • Head = 9\%

    • Anterior leg (one leg) = 9\%

    • Posterior leg (one leg) = 9\%

    • Back = 18\%

    • Chest (front of trunk) = 18\%

    • Perineum = 1\%

    • Example Calculation: Front of trunk (approximated as 18\%), including genitalia (1\%), and front of both legs (9\% \text{ per leg} \times 2 = 18\%) sums to 18\% + 1\% + 18\% = 37\%.