Common cutaneous bacterial infections Faghihi. G. Dermatology professor Isfahan University of Med.

Normal skin is a barrier against microbial pathogens

Predisposing factors to Bacterial Skin Infections : Neutropenia HIV infection IV Drug ABUSE Diabetes Parasitic Infestations Wounds,burns,abrasions Atopic disease Alcoholism MRSA Abscess and Surrounding Cellulitis in Arm of Patient with HIV Infection

Some other conditions as risk factors for bacterial cut. Infections For example : poor hygiene friction and wearing tight clothing seborrhea

Common important bacterial skin infections Include: Impetigo folliculitis furuncles carbuncles cellulitis erysipelas

Impetigo pustules or bullae that rupture and become crusted usually appears on the face, especially around nose and mouth mainly affects infants and children

The infection is spread by direct contact with lesions or with nasal carriers. The incubation period is 1–3 days after exposure to Streptococcus and 4–10 days for Staphylococcus

The most common pathogen Both bullous and nonbullous are primarily caused by Staphylococcus aureus with Streptococcus also commonly being involved in the nonbullous form.

Risk factors for Impetigo Atopic dermatitis parasitosis Trauma Burns minor abrasions Sports(direct contact)

Diagnosis usually clinically smear and culture definitely Leucocytosis ….. About 50 % patients

Children who get impetigo: should not attend school or daycare. They should not have close contact, with other children

limited uncomplicated impetigo Treatment(topical): Ointment mupirocin Ointment retapamulin Cream fusidic acid Equally as effective as oral Ab.

Extensive or accompanied systemic symptoms or lymphangitis(systemic Ab Penicillins( dicloxacillin, flucloxacillin or Alternatively amoxicillin combined with clavulanate Cephalosporins Clindamycin Macrolids In cases of severely ill/ immunocompromised IV ceftriaxone Iv ampicillin/sulbactam/cefuroxime

One major complication of impetigo: Post Strep GN

Efficacy of treatment of strep.impetigo is not known. In eradication acute P-S-G-N

MRSA decolonization

Impetigo Bockhart superifical staphyloccocal folliculitis

a superifical staphyloccocal folliculitis with thin-walled pustules at the folliclular openings.

Streptococcal intertrigo is a cutaneous condition seen in infants and young children, characterized by a fiery-red erythema and maceration in the neck, axillae or inguinal folds a distinctive foul odor and an absence of satellite lesions.

Treatment strep.intertrigo eliminate friction, heat, and maceration by keeping folds cool and dry Compresses with Burow solution 1:40 Treatment with penicillin V-K suspension, 125 mg orally 3 times a day 10 days

Bacterial folliculitis

The bacterial agent often responsible for folliculitis is Staphylococcus aureus The infection (hair follicles)can be shallow or deep can even lead to formation of inflammatory nodules or pustules which will surround the hair follicle.

superficial folliculitis (the most common form) Deep folliculitis (sycosis) Folliculitis most commonly occurs:// Beard area in men Scalp Upper trunk (chest, under breasts, in armpits) Buttocks Thighs Groin

Pseudomonas aeruginosa folliculitis hot tub folliculitis The infection is typically found in areas of the body, which are soaked under an improperly chlorinated hot tub or wirlpools. The typical body parts affected ::are buttocks, hips, legs and thighs ,face and neck are spared. It is self limited(7-14 Days) Sometimes for widespread infection or immunosuppressed or febrile ,ill patients: oral quinolone/topical gentamycin

Folliculitis Treatment Superficial folliculitis may heal on its own within 1 to 2 weeks Applying antibiotic ointments like Bacitracin, (bacitracin + neomycin + polymyxin B), or (mupirocin), washing with antibacterial soaps may help in more resistant cases In a deep folliculitis and recurrent cases, oral antibiotics (dicloxacillin, cephalosporins) may be needed. Folliculitis caused by MRSA requires treatment by antibiotics chosen on the basis of antibiotic sensitivity test (1). S. aureus carriers may be treated with mupirocin ointment in the nasal vestibule as previously said... Family members may be also treated by mupirocin to eliminate the carrier state and prevent re-infection

(boil ) furuncle Furuncles are skin abscesses caused by staphylococcal infection, which involve a hair follicle and surrounding tissue.

A carbuncle is a coalescence of several inflamed follicles into a single inflammatory mass with purulent drainage from multiple follicles. Constitutional symptoms, including fever and malaise, are commonly associated with these lesions but are rarely found with furuncles.

Diff Dx furuncles or carbuncles Ruptured epidermal cysts or pilar cysts Acne conglobata Hidradenitis suppur.

Patients with recurrent furunculosis should be evaluated: predisposing factors such as obesity, diabetes, occupational or industrial exposure to inciting factors, nasal carriage of Staphylococcus aureus or ,/methicillin-resistant S. aureus (MRSA) colonization.

Furuncles treat./ Treatment with warm compresses antiseptic sol./ or incision and drainage Systemic antibiotics:(multiple furuncles,severe illness, systemic signs, immunosuppresed , cellulitis around lesions , Areas like nose, Ear canal ,face and genitalia and acral parts: Cloxacillin,dicloxacillin,CA-MRSA: (Cotrimoxazole , doxy, clinda )

Bacterial cellulitis

Cellulitis is a deep infection of the skin, (dermis/ subcutis) usually accompanied by generalized (systemic) symptoms such as fever and chills.

streptococci , Staphylococcus and H streptococci , Staphylococcus and H.influenza, are the most common causes of cellulitis.

Cellulitis causes the affected area of skin to turn red, painful, hot and swollen

Risk factors for cellulitis a skin condition such as eczema or a fungal infection of the foot or toenails (athlete’s foot) can cause small breaks to develop in the surface of the skin. having a weakened immune system (as a result of health conditions such as HIV or diabetes, or as a side effect of a treatment such as chemotherapy lymphoedema – a condition that causes swelling of the arms and legs, which can sometimes occur spontaneously or may develop after surgery for some types of cancer Venous insufficiency intravenous drug abuse (injecting drugs such as heroin)

Cellulitis secondary to tinea infection.

Venous Insufficiency With Supra-Imposed Ulceration and Severe Cellulitis

In healthy adults isolation of an etiologic agent is difficult and unnecessary. If the patient has: diabetes, an immunocompromising disease, or persistent inflammation: blood cultures or aspiration of the area of maximal inflammation may be useful.

Indications for IV antibiotics in cellulitis Severely ill patients those whose condition is unresponsive to standard oral antibiotic therapy Immunosuppressed patients Patients with facial cellulitis Any patient with a clinically significant concurrent condition, including lymphedema and cardiac, hepatic, or renal failure Individuals with newly elevated creatinine, creatine phosphokinase, and/or low serum bicarbonate levels or marked left-shift polymorphonuclear neutrophils

In cases of cellulitis without draining wounds or abscess, streptococci continue to be the likely etiology, and beta-lactam antibiotics are appropriate therapy, as noted in the following: In mild cases of cellulitis treated on an outpatient basis, dicloxacillin, amoxicillin, and cephalexin are all reasonable choices Clindamycin or a macrolide (clarithromycin or azithromycin) are reasonable alternatives in patients who are allergic to penicillin fluoroquinolones are best reserved for gram-negative organisms with sensitivity demonstrated by culture Some clinicians prefer an initial dose of parenteral antibiotic with a long half-life (eg, ceftriaxone followed by an oral agent)

In otherwise healthy adults empiric treatment with a penicillinase-resistant penicillin, first-generation cephalosporin, amoxicillin-clavulanate (Augmentin), macrolide, or fluoroquinolone (adults only) is appropriate.

Antibiotics should be maintained for at least three days after the resolution of acute inflammation Adjunctive therapy includes: cool compresses; appropriate analgesics for pain; tetanus immunization; and immobilization and elevation of the affected extremity

more severe cases that require parenteral antibiotics to cover MRSA , vancomycin, daptomycin, tigecycline, ceftaroline, and linezolid are appropriate choices. However, vancomycin continues to be the drug of choice because of its overall excellent tolerability profile, efficacy, and cost

Erysipelas

an acute streptococcus bacterial infection of the upper dermis and superficial lymphatics.

Historically, the face was most affected; today the legs are affected most often The erythematous skin lesion enlarges rapidly and has a sharply demarcated raised edge.

It appears as a red, swollen, warm, hardened and painful rash, similar in consistency to an orange peel. More severe infections can result in vesicles, bullae, and petechiae, with possible skin necrosis.

Blood cultures are unreliable for diagnosis of the disease, but may be used to test for sepsis. Elevation of (ASO) titer occurs after around 10 days of illness. Erysipelas must be differentiated from: herpes zoster, angioedema, contact dermatitis, and diffuse inflammatory carcinoma of the breast.

ERYSIPELOID

Acute cut,. infection with Erysipelothrix rhusiopathiae Acute cut,. infection with Erysipelothrix rhusiopathiae. This type of bacteria is found in fish, birds, mammals, and shellfish. It usually affects people who work with these animals (such asfishermen , farmers or butchers).

Symptoms warmth, tenderness, and redness (non purulant cellulitis)on the skin Treatment Antibiotics, especially penicillin, are used to treat alternatives: erythromycin cephalosporine tetracyclines The infection rarely spreads. It may be self limited.

ERYTHRASMA

Chronic superficial bacterial skin infection Corynebacterium Minutissimum inside startum corneum Wood light examination of erythrasma

The patches of erythrasma are initially pink, but progress quickly to become brown and scaly (as skin starts to shed), which are classically sharply demarcated. Erythrasmic patches are typically found in intertriginous areas (skin fold areas - e.g. armpit, groin, under breast) - with the toe web-spaces being most commonly involved. The patient is commonly otherwise asymptomatic. The diagnosis can be made on the clinical picture alone. It is prevalent among diabetics and the obese, and in warm climates; it is worsened by wearing occlusive clothes.

Treatment of erythrasma

Aluminium chloride 20% improved hygiene topical azoles topical fusidic acid oint. whitefield(SA +Bezoic acid) oral erythromycin or tetracyclines

موفق باشید erythrasma