15.2 Integumentary Diagnosis and Management

The current FNP-BC Test Content Outline scores Integumentary as its own body system and again lists eye, ear, and skin agents among the drug classes. Implementation items will ask whether you incise, cover MRSA, refer a burn, or leave a possible melanoma alone. Diagnosis items will ask you to name the rash before you pick the cream.

Cellulitis, abscess, and impetigo

Cellulitis is a spreading dermal infection without a drainable pocket: warmth, erythema, and tenderness, often on a break in the skin. Treat with systemic antibiotics aimed at streptococci and methicillin-susceptible S. aureus (cephalexin is the usual first line in a nontoxic adult) and elevate the limb. Abscess is a walled collection. Fluctuance, a pointing center, or ultrasound fluid means incision and drainage is the definitive therapy. Antibiotics do not replace a knife. Add MRSA-active oral coverage (trimethoprim-sulfamethoxazole or doxycycline; clindamycin only if local resistance and a D-test allow it) when there is surrounding cellulitis, fever, immunocompromise, a facial location, or other systemic signs. Packing is not mandatory for a small, well-drained cavity; the exam point is source control.

A 28-year-old with a 2-cm fluctuant buttock nodule and no fever needs drainage today, not a 10-day course “to see if it opens.” A 72-year-old with a red, hot lower leg, no fluctuance, and lymphangitic streaking needs antibiotics and close follow-up — and a second look for DVT, stasis dermatitis, or necrotizing infection if pain is out of proportion or the patient is toxic.

Impetigo is a superficial infection, often in school-age children: honey-colored crusts on the face or extremities. Limited nonbullous disease can be treated with topical mupirocin. Numerous lesions, bullous disease, or outbreaks in the household need an oral agent (cephalexin, or a MRSA-active choice when that is the local pattern). Children stay out of school until they have been treated for the interval your public-health guidance uses — commonly 24 hours of antibiotics.

Tinea, candida, psoriasis, and eczema

These four are the rash differential the exam recycles. Get the pattern right before you write a steroid.

A groin rash that is annular with a scaly leading edge is tinea cruris. Satellite pustules in a moist fold are candida. Do not put a high-potency steroid on tinea — you will create tinea incognito. Do not put an azole on flexural psoriasis and declare victory. Scalp “dandruff” that is actually tinea capitis in a child needs oral terbinafine or griseofulvin plus household comb hygiene; topical cream will not reach the follicle.

Acne and rosacea

Acne is a stepped disease. Comedonal disease starts with a topical retinoid (adapalene is available over the counter) plus benzoyl peroxide. Inflammatory papules and pustules add a topical antibiotic combined with benzoyl peroxide — topical antibiotics are never monotherapy because resistance arrives fast. Moderate-to-severe inflammatory acne that fails topicals gets an oral tetracycline (doxycycline, minocycline, or sarecycline) for a limited course, still paired with benzoyl peroxide and a retinoid, then stepped down. Combined oral contraceptives or spironolactone can help selected females. Isotretinoin is for nodulocystic acne, scarring disease, or failure of systemic therapy. The FNP refers; iPLEDGE, monthly pregnancy testing, and teratogenicity are not casual primary-care add-ons. Counsel that benzoyl peroxide bleaches fabric and that oral tetracyclines need sun caution and are not for pregnancy.

Rosacea is central-face erythema, flushing, telangiectasias, and papulopustules without comedones. Triggers include heat, alcohol, spicy food, and sun. First-line topicals are metronidazole, ivermectin, or azelaic acid. Low-dose doxycycline treats inflammatory papules. Refer ocular rosacea (grit, photophobia, lid margin disease) and phymatous change. Treating rosacea with an acne retinoid-antibiotic stack because “it looks like pimples” is the trap.

Bites, burns, and pigmented lesions

Bite wounds need copious irrigation, tetanus update, and a decision about closure. Cat bites and most puncture wounds are high-infection and are usually left open; dog lacerations on the face may be closed after thorough washout. First-line prophylaxis or treatment is amoxicillin-clavulanate (covers Pasteurella, streptococci, anaerobes). Doxycycline plus an anaerobic agent is a common penicillin-allergy path; do not use cephalexin alone for a cat bite. Human bites (including clenched-fist injuries) are contaminated and need the same coverage plus a hard look for tendon or joint violation. Rabies immune globulin and vaccine are for bats and for unprovoked or unobservable wild-mammal exposures — start the conversation the same day, do not “watch the raccoon.”

American Burn Association referral is conceptual and exam-critical: burns of the face, hands, feet, genitalia, perineum, or major joints; circumferential burns; significant full-thickness injury; large TBSA partial-thickness burns; electrical or chemical injury; inhalation; and children when the hospital lacks pediatric burn expertise. Cool with clean water, cover, give analgesia, and update tetanus. Do not apply ice, butter, or toothpaste. Rule-of-nines or a Lund-Browder chart estimates TBSA; the patient’s palm is about 1%.

Melanoma is the pigmented-lesion emergency you do not treat in the office with cryotherapy. Use ABCDE — Asymmetry, irregular Border, Color variation, Diameter larger than 6 mm (smaller lesions can still be melanoma), and Evolving — plus the ugly-duckling sign (the mole that does not match the patient’s other moles). Refer suspicious pigmented lesions for full-thickness biopsy by someone who will not destroy the architecture. The FNP does not freeze a possible melanoma. That single sentence is worth an item.

Pressure injury, infestations, urticaria, and severe drug rash

Pressure-injury staging is conceptual, not a wound-care fellowship:

Do not reverse-stage a healing Stage 4. Offload, manage moisture, optimize protein, and involve wound care for 3–4 and for unstageable wounds.

Scabies is intense nocturnal itch with burrows in finger webs, wrists, and genitals; infants can have palms, soles, and the scalp. Treat the patient and close contacts with permethrin 5% from neck to toes (include the head in infants), repeat in one week per product and guideline, and wash linens on heat. Itch can last two weeks after successful kill — that is not automatic treatment failure. Lice are treated with permethrin 1% or another pediculicide plus wet combing; nits alone after treatment are not a reason to keep a child out of school under current AAP-style guidance.

Urticaria is itchy, transient wheals. If the airway, breathing, and blood pressure are normal and there is no lip-tongue swelling, a second-generation antihistamine is the plan. Anaphylaxis is a multi-system or hypotensive emergency: intramuscular epinephrine in the mid-anterolateral thigh first, then antihistamine, oxygen, and emergency transport. Do not start with a steroid and watch.

A simple morbilliform drug rash is widespread pink macules after a new medicine, often an antibiotic, in a well patient without mucosal injury. Stop the culprit when you can and support. Stevens–Johnson syndrome and TEN announce themselves with skin pain, dusky targetoid lesions, blistering, a positive Nikolsky sign, fever, and mucosal erosions (mouth, eyes, genitals). Stop the drug and send to the emergency department. Do not treat that picture with an office medrol dose pack and a follow-up next month.