Skin and Subcutaneous Tissue Infections

        Infectious Disease

25 cards   |   Total Attempts: 182
  

Cards In This Set

Front Back
Impetigo
Answer 1
·begins as small vesicles that rapidly pustulate and rupture, drying to form the characteristic “honey-colored crusts”, which may coalesce ·most common in children, and during the hot, humid summer weather. Epidemics common. ·painless; heals without scarring ·*group A strep (Strep pyogenes) most common historically, but Staph aureus just as common now ·Tx: -topical Mupirocin (Bactroban) -dicloxacillin -erythromycin -cephalexin
Erysipelas
Answer 2
-distinctive type of cellulitis with prominent lymphatic involvement -almost always due to group A strep; occ. Staph aureus -historically, most common on face, now 70-80% are on the lower extremities -painful lesion with bright red, edematous, indurated appearance *sharply demarcated border from adjacent normal skin Tx: -dicloxacillin -nafcillin or oxacillin -cephalexin -cefazolin -erythromycin -Vanco, if MRSA suspected
Cellulitus
Answer 3
An acute spreading infection of the skin that extends deeper than erysipelas & involves sub-Q tissues ·group A strep and Staph aureus are the most frequent organisms; other β-hemolytic strep (B, C, G) also ·Vibrio vulnificus à associated with salt water ·erythema, edema, tenderness, warmth of skin ·systemic symptoms (chills, fever, tachycardia, hypotension) common and often precede clinical findings à suggests bacteremia ·regional lymphadenopathy ·search for portal of entry
Cellulius Cont.
·if systemically ill-appearing, admit for blood cultures, IV abx, etc. ·Diff. Dx: -Bullous impetigo -Myositis -Skin abscesses -Chronic venous stasis -Toxin syndromes -DVT -Fasciitis -Septic arthritis/osteo ·Tx: PO amox/clav dicloxacillin,cephalexin,·clindamycin IV · ·oxacillin · ·cefazolin · ·vancomycin (if MRSA suspected) ·TMP/SMZ or erythro
Lymphangitis
Answer 5
Develops when an infection is not contained locally but spreads along lymphatic channels - most often group A strep, but other streptococci common; Staph aureus less common -systemic sx may develop quickly, before evidence of infection at initial site of inoculation -red, linear streaks extend toward regional LN’s, which are enlarged and tender -peripheral edema is common -bacteremia often complicates -recurrent infx common with chronic lymphedema
Folliculitus
Answer 6
-pyoderma within hair follicles and apocrine glands -small (2-5mm), erythematous, sometimes pruritic papules, pustules -Staph aureus usual etiologic organism -Pseudamonas aeruginosa à “hot tub” folliculitis -enteric gram (-)’s and Candida are uncommon, but consider in immunocompromised hosts *saline compresses, topical antibacterials (mupirocin) or antifungals (clotrimazole) usually sufficient
Furuncles
Answer 7
Deep inflammatory nodule that develops from preceding folliculitis -occur along hair follicles and where we perspire (neck, face, axillae, buttocks) -Staph aureus almost invariably etiologic organism -firm, tender, red nodule that commonly becomes fluctuant and sponteously drains
Carbuncle
Answer 8
More extensive process extending into sub-Q fat, where multiple septated abscesses develop -pt. may be acutely ill with systemic findings
Risk Factors and Tx for Carbuncles
predisposing factors:diabetes, obesity, poor hygiene are all -small lesions generally respond to warm compresses, abx -larger carbuncles may require admission, operative debridement, IV abx. Abx: -cephalexin -clindamycin -diclox -vancomycin (if MRSA) -amox/clav -TMP/SMZ -if recurrence a problem, nasal swab to rule out colonization with S. aureus (especially MRSA)
Hydradenitis Suppurativa
Answer 10
Chronic disease of apocrine glands in axillary, genital, and perineal areas -tender reddish-purple nodules that slowly become fluctuant and drain, with irregular sinus tracts and new crops of lesions developing -initially not infected, but infection frequently develops secondarily à polymicrobial *very difficult problem to take care, especially when the process is extensive -abx (based on culture results) and warm compresses may be helpful, but surgery often required
Stasis Dermatitis
Answer 11
Inflammatory skin disorder of the lower legs due to chronic venous insufficiency -generally affects middle-aged to elderly folks -obesity, prior trauma/surgery, DVT, CHF are all predisposing factors -disrupted function of one-way valvular system in the deep venous plexus results in backflow to the superficial system à  venous pressure à ↓ valvular competency -precursor to more serious problems à ulcerations, episodes of cellulitis
Signs and symptoms of Stasis Dermatitis
Signs & Symptoms: -insidious onset of pruritits -history of dependent leg edema which worsens as day progresses -medial ankle most frequently + severely involved -diffuse red-brown-purple skin ∆’s -atrophic patches, loss of hair -often “weep” serous fluid **damage irreversible; key is to slow progression
Treatment of Stasis Dermatitis
*Key to most patients is to get the chronic edema under control à lifestyle modification ·compression stockings/ACE wraps (if no PVD) · bedrest even if just few hours/day ·diuretics if no contraindication ·consider admission to SAR when pt. can’t manage on their own -topical steroids to ↓ inflammation in short-term -emollients (Eucerin, etc.) long-term
Herpes Zoster(Shingles)
Answer 14
Caused by varicella-zoster virus (VZV) *unilateral, vesicular eruption with dermatomal pattern -thoracic and lumbar dermatomes most common -may involve the CN’s *herpes zoster opthalmicus à sight-threatening -generally, pain precedes rash by 48-72 hrs – often misdiagnosed early. -new lesions continue to form for 3-5 days, longer in immunocompromised pts
Herpes Zoster contd and Tx
Consider “contagious” until lesions fully scabbed over -may take a month or more for skin to return to normal -CSF analysis may show pleocytosis even without evidence of mengitis -acyclovir will ↓ amount and shorten duration of lesions *post-herpetic neuralgia (PHN) will affect >50% over 50 yo and pain can be incapacitating in some -NSAIDS/narcotics, lidocaine patches, tri- cyclics and other antidepressants, anti-Sz drugs, biofeedback, etc. have all been used -prednisone has been shown to possibly ↓ % of PHN