Dermatology

Published on 02/06/2015 by admin

Filed under Internal Medicine

Last modified 22/04/2025

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Pain localized to the dermatome that will be affected by the skin lesions → precedes skin manifestation by 3-5 days.

Rash: erythematous maculopapules affecting one dermatome → maculopapules evolve into vesicles and pustules of various sizes (a distinguishing characteristic from HSV, in which the vesicles are of uniform size) by the 4th day → vesicles subsequently become umbilicated and then form crusts that generally fall off within 3 wk.

Ramsay Hunt syndrome: involvement the trigeminal nerve → painful ear, w/vesicles on the pinna and external auditory canal, facial palsy.

Treatment

PO antivirals can ↓ acute pain, inflammation, and vesicle formation when Rx is begun within 72 hr of onset of rash. Rx options are (adjust dose for renal failure):

• Valacyclovir 1000 mg × 7 days

• Famciclovir 500 mg tid × 7 days

• Acyclovir 800 mg 5× qd × 7-10 days

Immunocompromised pts: IV acyclovir 10 mg/kg q8h (infusion over 1 hr ) for 7-14 days

Consider adding prednisone in pts >50 yr old within 72 hr of clinical presentation or if new lesions are still appearing. Initial dose is prednisone 40 mg/day ↓ by 5 mg/day until finished. Corticosteroids ↓ in the use of analgesics and time to resumption of usual activities, but there is no effect on the incidence and duration of postherpetic neuralgia.

Postherpetic neuralgia Rx:

• Gabapentin 100-600 mg tid

• Lidocaine patch 5% applied to intact skin to cover the most painful area for up to 12 hr within a 24-hr period

Vaccination

Immunocompetent adults ≥50 yr old: single dose of varicella-zoster vaccine (VZV, Zostavax)

Adults who are VZV sero(−) (never had varicella): immunize w/2 doses of varicella vaccine (Varivax).

B. Pressure Ulcers

Stage I: Nonblanchable erythema of intact skin and/or boggy, mushy texture.

Stage II: Partial-thickness skin loss involving the epidermis and/or dermis. May also manifest as an intact or ruptured serum-filled blister.

Stage III: Full-thickness loss/damage or necrosis of subcutaneous tissue that may extend down to underlying fascia/muscle. Possible undermining/tunneling.

Stage IV: Full-thickness skin loss with exposed muscle, bone, or joint capsule. Sloughing or eschar may be present, often with undermining/tunneling.

Deep tissue injury: Purple/maroon localized area of discolored, intact skin or blood-filled blister resulting from damage of underlying tissue from pressure and/or shear.

Unstageable: Full-thickness tissue loss with the base of the ulcer covered by slough or eschar in wound bed.

Treatment

↓ Prolonged skin exposure to moisture, urine, or stool. Rx dry, cracking skin.

Use repositioning and pressure-reducing devices for support while in bed or chair.

Clean at each dressing change; necrotic tissue should be débrided quickly because it delays wound healing (except for heel ulcers).

Wound irrigation should not exceed 15 psi; best done with an 18-gauge angiocatheter.

↓ Pressure by using foam mattress, dynamic support surface (e.g., low-air loss bed), and frequent repositioning (e.g., q2h or, in cases of poor perfusion, more frequently).

(−) Pressure devices (Vac devices) help in wounds that have significant drainage.

Correct poor nutrition through improved diet.

C. Psoriasis

Primary psoriatic lesion: erythematous papule topped by a loosely adherent scale. Scraping the scale results in several bleeding points (Auspitz’s sign).

Chronic plaque psoriasis (80% cases): symmetric, sharply demarcated, erythematous, silver-scaled patches affect primarily the intergluteal folds, elbows, scalp, fingernails, toenails, and knees.