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Dr. Cleaver Lecture notes from Sept. 17, 1999


I.     Bacteria Skin Infections Are Common Problems in Dermatology and General Medicine
        A.     Appropriate diagnosis and treatment with appropriate presentation
        B.     Approach to recurrent and resistant infections
        C.     Review use of some of the new antibiotics
        D.     Stress importance of proper diagnosis culture and and underlying health status

II.     Impetigo (Superficial epidermal bacterial infection)
        A.     Clinical characteristics
                1.     Golden-crusted erosions, superficial bullae or vesicles with turbid fluid
                2.     Expansion laterally in annular fashion
                3.     Usually on face, hands, genitalia, scalp
                4.     Pruritus possible
                5.     Typically, no accompanying constitutional symptoms
                6.     Ecthyma: deep impetigo often on legs, healing with scars

        B.     Etiology
                1.     Cause: cocci-type bacteria
                        a.     Streptococcus: usually non bullous
                        b.     Staphylococcus: commonly bullae and pustules
                2.     Poor hygiene, moist climates, crowding possibly exacerbating susceptibility

        C.     Associated conditions
                1.     Staphylococcal impetigo - possible association with immunodeficiency disease (e.g.
                        chronic granulomatous disease of childhood)
                2.     Neonatal type - highly contagious and constant threat in nurseries
                3.     STAPHYLOCOCCAL SCALDED SKIN SYNDROME (SSSS) - Can be a true
                        derm. emergency
                        a.     Generalized, confluent, superficially exfoliated. Dx occurring most commonly in
                                neonates and young children.
                        b.     Must differentiate from TEN, which may be drug induced
                        c.     Caused by Staphylococcus, group 2-phage 71 - effect of exotoxin
                4..     Streptococcal impetigo
                        a.     Post streptococcal glomerulonepohritis in 2-5% cases
                        b.     Glomerulonephritis (GLN): resolution in many cases but possible precursor of
                                chronic renal disease (may not influence course, even if treated)
                        c.     Usually strains type 49, 55, 57, 60 and M-2 related to nephritis
                5.     Blistering Distal Dactylitis
                        a.     Characteristic - tense, superficial blisters over tender erythematous base over
                                volar fat pad of the phalanx
                        b.     Age - usually 2 to 16
                        c.     Group A - beta streptococcus as cause
                        d.     Similar to Strep. cellulitis

        D.     Therapy
                1.     Removal of crusts
                2.     Topical antiseptics (Betadine) or antibiotics four times daily - mupirocin, bacitracin
                        or polysporin; No neosporin (common topical sensitizer)
                3.     Systemic antibiotics
                        a.     Pen VK - (drug of choice if Strep.) 250 mg QID
                        b.     Erythromycin, cloxacillin or cephalosporin - PO 250-500 ig P.O. QID if Staph
                4.     Prevention of contact with other children (avoidance of same towels)

        E.     Recurrent Staphylococcal Impetigo
                1.     Topical Bacitracin or Mupirocin for chronic carriage (usually nasal)
                2.     Rifampin and Dicloxacillin
                3.     Rifampin and Trimethoprim
                4.     Bacterial Interferences - (S. aureus 502A)

        F.     Methicillin-resistant Staphylococcus aureus
                1.     Parenteral Vancomycin
                2.     Trimethoprim/sulfamethoxazole
                3.     Rifampin and Trimethoprim
                4.     Fluoroquinolones

III.    Erythrasma
        A.     Clinical characteristics
                1.     Dry, scaly, reddish-brown plaques with the fine inconspicuous scale (looks like T.
                2.     Most commonly in axilla, groin, submammary areas
                3.     Frequently in obese, diabetic, or debilitated patients
                4.     Wood's lamp examination: coral red fluorescence visible

        B.     Etiology: Corynebacterium minutissimum

        C.     Differential diagnosis
                1.     Intertrigo: negative Wood's light examination
                2.     Dermatophytosis: positive KOH, active scaly border

        D.    Therapy
                1.    Cleansing, drying agents
                2.     Systemic erythromycin or tetracycline
                3.     Recurrence not infrequent

IV.     Folliculitis - Furuncles - Carbuncles
               A.     Clinical Characteristics and Types
                        1.     Superficial pustular follicular infection, usually Staphylococcal (Impetigo of
                        2.     Folliculitis
                                a.     Follicular pustules
                                b.     Pruritus very common
                                c.     Intertriginous areas commonly involved
                                d.     Exacerbation from moisture, poor hygiene
                        3.     Sycosis Vulgaris
                                a.     Perifollicular beard area region presence of pustules and papules
                                b.     Pustules rupture after shaving and then from a fresh crop.
                        4.     Furuncle (boil): deep infection with centra necrosis
                        5.     Carbuncle
                                 a.     Multiple boils with fistula formation
                                 b.     Surrounding skin erythematous and tender
                                 c.     Usual location: back, neck, intertriginous areas
            B.     Therapy
                    1.     Folliculitis
                            a.     Removal of exacerbating factors
                            b.     Topical antiseptics, cleansing
                            c.     Recurrent folliculitis: culture from patient's nose and contacts' noses; long
                                    term antibiotics perhaps required
                    2.     Carbuncles and furuncles
                            a.     Incision and drainage, lesion packed with gauze
                            b.     Systemic antibiotics after appropriate cultures
                            c.     If recurrent, search for underlying illnesses necessary: diabetes, leukemia,
                                    immunodeficiency disorders
                    3.     Recurrent furunculosis, carbuncles and folliculitis
                            a.     Bacterial interferences
                            b.     Rifampin and dicloxacillin
                            c.     Clindamycin

V.     Erysipelas (Streptococcal Cellulitis)
        A.     Clinical characteristics
                1.     Erythematous, swollen, tender, sharply marginated area with active advancing
                2.     Induration common
                3.     Blisters over lesion possible
                4.     Acute course
                5.     Malaise, fever (usually greater than 100 F), leukocytosis, and lymphadenitis
                6.     Lymphedema: possible result from recurrent episodes

        B.     Etiology and pathogenesis
                1.     Beta-hemolytic Streptococci
                2.     Inoculation in skin, dissection along tissue planes
                3.     Occurrence more frequent in patients with chronic lymphedema, recurrent tendency

        C.     Therapy
                1.     Systemic penicillin, 1 gm daily for 10 days, or erythromycin
                2.     For recurrent infections prolonged therapy perhaps necessary

        D.     Resistant Streptococcal Cellulitis
                1.     Confirm organism is strept
                2.     Rifampin and Dicloxacillin
                3.     Prophylactic Benzathine - Pen.
                4.     Prophylactic erythromycin

VI.    Cellulitis and Fascitis
        A.     Cellulitis
                1.     Characteristic suppurative inflammation involving particularly the subcutaneous tissue.
                2.     Causative agent - Streptococcus pyogenes, staph and others also implicated.
                3.     Usually some type of discernilele wound.
                4.     Often mild erythema, tenderness, malaise, chills and fever
                5.     Aggressive antibody therapy

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