Skin Infections Flashcards
Complications of untreated skin and soft tissue infections (SSTI)
Sepsis
Underlying bone infection
Primary SSTI
Previously healthy skin, usually single pathogen
Secondary SSTI
Previously damaged skin, usually polymicrobial
Complicated SSTI
Deeper layers (muscle, fascia), usually require surgical intervention OR immunocompromised pts
Tinea unguinum
Nails
Tinea manuum
Hands
Predisposing factors to fungal infections
Diabetes Impaired circulation Immunosuppressive drugs Poor nutrition and hygiene Skin occlusion Warm and humid climates
Tinea pedis
Men > women Whites > blacks Adults > children Athletes > non-athletes Shoes > sandals
Presentation of tinea pedis
Soggy, malodorous, thickened skin Acute vesicular rash Fine scaling of the affected area with varying degrees of inflammation Cracks and fissures may also be present Typically involves lateral toe webs -Between 4th and 5th or 3rd and 4th toes Can spread to sole or instep -Rarely to the dorsum
Presentation of tinea corporis
Smooth and bare skin
-Begin as small, circular, red, scaly areas
Spread peripherally and borders may contain vesicles or pustules
Tx goals for fungal infections
Provide symptomatic relief
Eradicate infection
Prevent future infection
Nonprescription tx for fungal infections
Appropriate for tinea pedis, corporis, cruris
Capitis and unguium require prescription tx
Clotrimazole 1% and miconazole nitrate 2%
Inhibit biosynthesis of sterols and damage the fungal cell wall, altering permeability resulting in loss of essential intracellular elements
Apply BID for up to 4 wks
Nonprescription
Mild skin irritation can occur at application site
No drug-drug interactions with nl topical use
Terbinafine 1% topical
Inhibits squalene epoxidase resulting in accumulation of squalene within fungal cell causing cell death
Apply BID for up to 4 wks
-Some trials showed resolution of tinea pedis after 7 days of tx
Product selection of fungal infection tx
Ointments, creams, powders, and aerosols
Creams are the most efficient and effective
Sprays and powders are good adjuncts for prevention
Terbinafine oral
First line for fungal nail infections
-250 mg daily for 6 wks-fingernails
-250 mg daily for 12 weeks- toenails
CBC and ALT/AST levels at baseline and every 4-6 wks during tx- rare but serious hepatic failure…don’t use with chronic or acute liver disease
Psoriasis dx
Nail pitting, rash elsewhere on body, FHx of psoriasis
Lichen planus dx
Nail atrophy, scarring at proximal aspect of nail
Yellow nail syndrome dx
Multiple nails turn yellow, grow slowly, increased longitudinal and transverse curvature, intermittent pain and shedding, associated with chronic sinusitis, bronchiectasis, lymphedema
Trauma of nails
Single nail affected, homogeneous alteration of nail color and altered shape of nail
Folliculitis
Inflammation of hair follicle (stye)
Furuncles
Infections of hair follicle that extends beyond follicle into subcutaneous skin layers
Carbuncle
Group of furuncles forming a single area
Abscess
Collections of pus within dermis or deeper tissues
Pathogen for folliculitis, furuncles, carbuncles, and abscesses
Typically S. aureus
Underchlorinated pools and hot tubs have resulted in some Pseudomonas infections
Tx for folliculitis, furuncles, carbuncles, and abscesses
Warm, moist compresses for follicultiis and small furuncles
I & D should be performed if inflamed cysts, carbuncles, abscesses, and large furuncles
Usually do not require systemic abx unless extensive area affected or systemic signs of infection
T: >38 degrees C or < 36 degrees C
Tachypnea >20 breaths/min or PaCO2 <32 mm Hg
Tachycardia > 90 bpm
WBC > 12,000 or <4,000
Mild bacterial SSTI (folliculitis, etc.)
Purulent infection with no systemic signs of infection