Common Skin Disorders & Infections Flashcards
Mole Classification
Junctional Nevus
Compound Nevus
Intradermal Nevus
Junctional Nevus: Usually flat, brown to black 1-10mm - Melanocyte nest @ epidermodermal junction
Compound Nevus: Brown, slightly or very elevated, 3-6mm - melanocytes @ epidermodermal junction and w/in dermis
Intradermal Nevus: Flesh-brown, smooth/hairy/warty, elevated, 3-6mm - Confined to dermis
Halo Nevus
Blue Nevus
Halo Nevus: Any mole surrounded by 2-6mm ring depigmentation - inflammation and melanocyte loss
Blue Nevus: Bluish gray, usually flat, 2-4 mm - deeply pigmented dendritic melanocytes in dermis
Acne Vulgaris
pilosebaceous unit of inflammation of certain body parts
-Most common in adolescents - comedones, papulopustules ,or nodule/cyst
4 factors: follicular hyperkeratinization, increase sebum, P. acnes w/in follicle, inflammation
Grades 1-4
Tx: Topical retinoids 1st line, topical antibiotics 2nd line
Rosacea
Chronic acneiform disorder of facial pilosebaceous unit
Capillaries have increased reactivity to heat and telangiectasis progresses
Onset 30-50 yo, commonly females
Exacerbated by hot liquid, spicy food, ETOH, sun/heat exposure
Tx: 1st line - topical abx if no papules/pustules - systemic Abx if moderate/severe - tetracycline, doxy, erythromycin
-Laser tx for telangiectasis
Rosacea Subtypes
Erythematotelangiectatic rosacea: redness, flushing, visible blood vessels
Papulopustular rosacea: redness, swelling, acne-like breakout w/o comedones
Phymatous rosacea: skin thickening with bumpy texture
Ocular rosacea: eyes red & irritated, eyelids swollen, can look like a sty
Rosacea Complications
Eye involvement - rare
Gram negative folliculitis
Permanent telangiectasis
Rhinophyma = soft tissue hypertrophy of nose w/ vasodilation
-mostly in men, correct w/ surgery
Folliculitis
Hair follicle infection - usually Staph aureus, Pseudomonas (hot tub - 72 hours after), and yeast (rare)
Red pimples w/ hair @ center - itch or burn
Tx: Warm compress, topical mupirocin, self-limited
Oral Abx have no benefit
Recurrent folliculitis is related to nasal S. aureus colonization - Intranasal Bactrim to supress
Pseudobarbae Folliculitis
Razor bumps - common in African Americans
Hair reenters skin -> FB inflammatory response
Firm papules w/ embedded hair
Tx: 1st line - stop shaving, laser hair removal
Furuncles/Carbuncles
Furuncle (boil): abscess caused by staph infection hair follicle
Carbuncle: cluster furuncles progress to fluctuant lesion
-May spontaneously rupture & extrude pus and necrotic tissue
Common w/ DM, obesity, malnutrition, heme dx
Tx: <5cm - no abx, just hot compress
I&D if fluctuant, Bactrim/Keflex if >5 cm
Impetigo
Contagious strep/staph infection - red/honey-colored crusts
Usually around mouth and nose
Scratching spreads infection
Tx: Bactroban 1st line, oral Abx - Doxy, Clinda if severe
Moles
Well-defined borders, uniform in color - brown/black
Appear before 20 yo
Melanocytes or nevus cell composition, can change and lose pigment over time
Dx: ABCDE - biopsy if concerning
Tx: Shave/excision
Solar Lentigo
Flat, brown spots up to 1 in diameter from sun exposure
Benign and painless
Tx: 1st line - cryotherapy
Tretinoin cream to lighten
Seborrheic keratitis
Multiple benign lesions on torso
Isolated or hundreds - appear in 4th-5th decade, uncommon <30 yo
Warty, scaly, hyperpigmented stuck on lesion
Tx: Cryotherapy, curettage, shave bx
Actinic Keratosis (AKs)
Precancerous for SCC
Rough, dry, scaly patch/growth - itchy/burning/sensitive
Can fall off and come back
From sun exposure, tanning bed - common in light-skinned
Tx: Nonhypertrophic - liquid nitrogen
- Hypertrophic - surgical curettage and send to path
- Multiple - 5-FU, Imiquimod
Melasma
Pregnancy mask - common w/ pregnancy and darker skinned
Tan/brown patches on cheeks, nose, forehead, chin
Triggers: sun, hormone change, cosmetics
Tx: self-limited, hydroquinone 1st line
-Tretinoin + steroids 2nd line
