Bacterial skin infections Dr Mohammad Arif Abid Impetigo

Bacterial skin infections Dr. Mohammad Arif Abid

Impetigo Common contagious superfacial skin infection Caused by Staph. aureus (80%) and strep. Pyogenes( 20%) clinical form Bullous impetigo Nonbullpus impetigo

Impetigo… History Began after an skin injury Children in closed contact have higher incedince Nasal colonization with St. Aureus can be a reservoir for reccrent skin infection Predisposing Warm Poor factors humid climate higen

Impetigo… Skin findings Localized / widespread Tow clinical forms exist Bullous impetigo Non-bullous impetigo

Impetigo…Skin findings Bullous impetigo It began as a bulla Thin-roofed bullae turn from clear to cloudy. Bulla collapse quickly, covered by honey-colored, stuck-on crust. Lesions enlarge and often coalesce. Minimal surrounding erythema. The thick crust accumulates in longer-lasting lesions

• Lesions are found in all stages of evolution Adenopathy may bepresent • The causative organism is Staphylococcus aureus

Impetigo…Skin findings Non-Bullous Impetigo (Crusted) Began as a vesicle or pustule Vesicle or pustules rupture, A tinea-like scalin border forms as the round lesions enlarge. The firmly adherent crust is honey to white brown Satellite lesions appear beyond the periphery Primary causes is streptococci

Impetigo… Non-skin Findings Systemic symptoms are infrequent. Lesions are generally asymptomatic and painless

Impetigo. . complications The incidence of acute nephritis is between 2% and 5% In the presence of nephritogenic strain of streptococci, the rate varies between 10% and 15%.

Impetigo… Treatment For limited, localized infections of non-bullous impetigo due to Staphylococcus aureus or strep. pyogenes, Mupirocin 2% ointment o cream , three times a day for 10 days Retapamoline ointment used two times a day for 5 days is an alternative. Fusidic acid cream has been used successfully for impetigo,

Impetigo… Treatment For widespread infections Cephalexin 250 mg 4 times/day 5 to 7 days Dicloxacillin 250 mg 4 times/day 5 to 7 days Azithromycin ( for penicillin allergic patients) 500 mg on day one 250 mg day 2 -5 Nasal carriers Mupirocine months 2 times/day for 5 day repeat every month for 3

Cellulitis. . . Description Cellulitis is an infection of the dermis and subcutaneous tissues characterized by fever erythema edema and pain

Cellulitis… history Localized The pain and renderness most susceptible populations are: people with liver cirrhosis, Rena failure Malnourishment human immunodeficiency virus Patients who have cancer and are on chemotherapy or who abuse intravenous drugs and alcohol

Cellulitis… history Cellulitis typically occurs near surgical wounds and trauma sites It may develop in apparently normal skin or at minor wound sites Recurrent episodes occur with local anatomic abnormalities that compromise the venous or lymphatic circulation The pinna and lower legs are particularly susceptible to recurrence

Cellulitis … Skin Findings A pre-existing lesion such as an ulecer, erosion may act as a portal of entry for the infecting organism. Athlete's foot may be a common predisposing condition cellulais of the lower extremities. An expanding red, swollen, tender or painful plaque with an indefinite border may cover a small or wide area. Palpation produces pain Vesicles, blisters, hemorrhage , necrosis, or abscesses may occur Regional lymphadenopathy sometimes occurs lymphangitis and adenitis are common with infection with Streptococcus pyogurmes Repeated attacks on the legs can impair lymphatic drainage, leading to chronically legs oedema

Cellulitis … Skin Findings The end stage of repeated infection of the leg includes dermal thicken and This is known as elephantiasis nostra

Cellulitis … Laboratory Mild to moderate leukocytosis and a mildly elevated erythrocyte sedimentation rate may be present. Cellulitis is most often caused by a group A streptococcus and Staphylococus aureus Many other bacteria can cause cellulitis Less common causative organisms include Erysipelothrix rhusiopathiae (erysipeloid) in fish, poultry, meat handlers, Aeromonas bydrophilia after swimming in fresh water, Vibrio species after swimming in salt water

Cellulitis…treatment Pain can be relieved with cool Burrows sulotion Elevation of the affected limb assists with drainage and will hasten recovery. Rest with elevation of the affected limb Empiric treatment with antibiotics aimd at staphylococcal and streptococcal organisms is appropriate A penicillinase resistant penicillin such as Dicloxacillin 500 -1000 mg orally Oral Amoxicillin/clavulanate 875/125 mg twice daily or 500/125 mg three times daily Cephalosporin such as cephalexin n 250 -500 mg four times daily Azithromycin 500 mg initial dose then 250 mg on days 2 -5 The mean time for healing after treatment is initiated is 12 days.

Cellulitis…treatment. . Non responding cases require intravenous antibiotics. Intravenous empiric therapy with coverage for group A streptococci and Staphylococcus aureus with cefazolin 1 g every 8 hours or Nafcillin 2 g every 4 -6 hours.

Erysipelas … Description An acute, inflammatory form of cellulitis that differs from other types cellulitis in that it is superficial with lymphatic involvement It is more superficial, involving the dermis upper subcutaneous tissue. The margins are more clearly demarcated from normal skin than those in classical cellulitis

Erysipelas … Description The most common pathogens are group A streptococci Group B streptococci are noted in infections in the newborn Infection may start at a break in the skin caused by a trauma, a surgical wound, an ulcer or insect bite or superficial fungal infection The site of entry is not always identified More common in infants, young children and the elderly

Erysipelas… history onset of the condition is sudden Prodromal symptoms last for hours and consist of malaise, myalgia chills, high fever 39 -40 and occasionally, anorexia and vomiting Adenopathy present and lymphangitis may also be

Erysipelas… skin findings The most common site of involvement is the lower leg , The face, arm and upper thigh are other common sites In the neonate, the periumbilical skin is a common site one (or more) red, tender and firm spot rapidly increases in size, to form a tense and deeply erythematous hot, sharply demarcated and uniformly elevated shiny patch with an irregular outline and raised border peau d'orange) The color becomes dark and deeply erythematous, and vesicles may appear at the advancing border and over the surface. Itching burning tenderness, and pain may be moderate or severe

FACIAL ERYSIPELAS

Erysipelas… skin findings streaks of Red sometimes painful, that extend toward lymph nodes. Lymphangitis regional attacks impair lymphatic drainage and the patient predisposes to more infection and permanent swelling. This series of events takes place most commonly in the lower legs of patients with venous stasis and ulceration. Repeated attacks may also occur in the genital skin

Erysipelas…treatment Treatment In acute episodes, Penicillin v orally 250 -500 mg four times a day for 2 week is the drug of choice. Amoxicillin is also effective. Diagnosis of a streptococcal origin should be reconsidered if the response to penicillin is not rapid. Two alternatives for patients who cannot take penicillin are azithromycin 500 mg on day 1 and 250 mg on day 2 to day 5, or clarithromycin 250 -500 mg every 12 hours for 7 -14 days. Bed rest and elevation of the affected limb is also indicated. Anticoagulant therapy should be considered in people taking bed rest who are at risk from venous thromboembolism.

Folliculitis. . Description It means an inflammation the hair follicle and there are several types Common types include: mechanical folliculit from persistent trauma tight clothing bacterial folliculitis Fungal folliculitis is less common but can result from untreated tinea corporis or tinea infection Bacterial folliculitis includes follicular impetigo, a superficial form of staphylococcal folliculitis, and sycosis barbae, a deep form occurring in the beard area

Folliculitis… History Usually the eruption is abrupt. Staphylococcal bacterial folliculitis can spread by trauma, scratching, or shaving. The distribution is variable; often the scalp, arms, legs, axillae and trunk are involved.

Folliculitis… Skin Findings . Dome-shaped pustules with small erythematous halos arise in the follicle These lesions are sometimes tender. In sycosis barbae, the inflammation is intense and deep there is marked tenderness.

Staphylococcal folliculitis

Folliculitis…treatment Heat, friction, and occlusion should be minimized. Antibacterial soap and warm wet dressings are helpful. Razors should be changed frequently to avoid reinfection. Mupirocin (Bactroban) applied three times daily for 5 days

Pseudofolliculitis Barbae (Razor Bumps, Ingrown Hairs) Description Pseudofolliculitis barbae is a papular and pustular, foreign body inflammatory reaction that can affect any individual who has curly hair and who shaves closely on a regular basis. This condition is a particular problem in people of Hispanic or African. American background It is often chronic, and can be disfiguring.

Pseudofolliculitis barbae (razor bumps)

Furuncles and carbuncles…Description A furuncle (boil) is walled off, deep an painful firm or fluctuant mass enclosing a collection of pus often. evolves from a superficial folliculitis Staphylococcus aurues is he most commonly associated organism, but other organisms (Escherichia coli pseudomonas aeruginosa and anaerobes Lactobacillus species may cause lesions Usually a bacteriologic study of the abscess identifies the local flora A carbuncle is an extremely painful deep interconnected aggregate of infected abscessed follicles

FURUNCLES AND CARBUNCLES

Furuncles and carbuncles…History Furuncles and carbundes are uncommon in children Occlusion and hyperhidrosis promote bacterial colonization Most affected patients have normal immune systems,

Furuncles and carbuncles…Skin Findings Any hair bearing site can be affected sites of high friction and sweating are most typically affccted these include the areas under the belt the anterior thighs the buttocks, the groin, the axillac, and the waist With a furuncle, a deep dermal or subcutaneous, red, swollen and painful mass later points towards the surface and drains through single openings

Furuncles and carbuncles…Skin Findings With a carbuncle, deep, tender. firm subcutaneous erythematous papules enlarge to deep-seated nodules than can be stable or become fluctuant within several days. Favored sites for carbuncles are the back of the neck, the upper back, and the lateral thighs.

CLINICAL MANIFESTATIONS The lesion begins as a deep, tender, firm, red papule that enlarges rapidly into a tender, deep-seated nodule that re mains stable and painful for days then becomes fluctuant The temperature is normal and there are no systemic symptoms. Pain becomes moderate to severe as purulent material accumulates. Pain is most intense in areas where expansion is restricted, such as the neck and external auditory canal. The abscess either re mains deep and reabsorbs or points and ruptures through the surface. The abscess cavity contains a surprisingly large quantity of pus and white chunks of necrotic tissue.

Furuncles and carbuncles…Nons-kin Findings With a furuncle, the patient remains afebrile. With a carbuncle, malaise, chills and fever may precede or occur during the height of inflammation

Furuncles and carbuncles… Treatment Furuncles and Carbuncles Warm, moist dressings are applied to the sion 15 -30 minutes several times a day. A culture and sensitivity is often appropriate for large or atypical lesions. Incision and drainage is the primary management for pointing, fluctuant lesions. antistaphylococcal antibiotic Dicloxacillin 250 -500 mg hour times daily for 10 days Cephalexin 250 -500 mg four daily for 10 days in Clindamycin 150 300 mg four times daily for days in adults