1 / 43

Bacterial Skin Infection

Bacterial Skin Infection. By Prof. Ashraf Al-Sawy MD. Staph. Aureus Infection. Direct infection of skin : impetigo, ecthyma , folliculitis , furunculosis , carbuncle, sycosis . Secondary infection: eczema, infestations, ulcers, …etc.

kerry
Download Presentation

Bacterial Skin Infection

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Bacterial Skin Infection By Prof. Ashraf Al-Sawy MD

  2. Staph. Aureus Infection • Direct infection of skin :impetigo, ecthyma, folliculitis, furunculosis, carbuncle, sycosis. • Secondary infection:eczema, infestations, ulcers, …etc. • Effect of bacterial toxin:staph.-associated scalded skin syndrome (SSSS), toxic shock syndrome.

  3. strepto. Infection (GAS)(gp A streptococci) • Direct inf. of skin or subcut. tissue:Impetigo, ecthyma, cellulitis, vulvovaginitis, perianal inf., strepto. ulcers, blistering distal dactylitis, necrotizing fasciitis. • 2ry inf.:eczema, infestations, ulcers, …etc.

  4. Tissue damage from circulating toxin:scarlet fever, toxic shock-like syndrome. • Skin lesions attributed to allergic hyper-sensitivity to strepto. antigens:erythemanodosum, vasculitis. • Skin dis. provoked or influenced by strepto. inf.:psoriasis especially guttate forms.

  5. Impetigo

  6. Acute contagious skin infection caused mostly by staph. Aureus and strept. • Affects children mainly esp. in summer times.

  7. Clinical types • 1- Non-bullous impetigo: • Caused by staph., strept. or both organisms. • 2- Bullous impetigo: • Caused by staph aureus.

  8. Non-bullous Impetigo • Staph. aureus or gp A stretp. (GAS) or both “mixed infections”. • May arise as 1ry inf. or as 2ry inf. of pre-existing dermatoses, e.g. pediculosis, scabies & eczemas. • An intact st. corneum is probably the most important defense against invasion of pathogenic bacteria.

  9. A thin-walled vesicle on erythematous base, that soon ruptures & the exuding serum dries to form yellowish-brown (honey-color) crusts that dry & separate leaving erythema which fades without scarring. • Regional adenitis with fever may occur in severe cases.

  10. Sites:Exposed parts eg. face & extremities. Scalp (in pediculosis). Any part could be affected except palms & soles. • Complications:Post-streptococcal acute glomerulo-nephritis “AGN” especially in cases due to strepto. pyogenes M. type 49.

  11. Varities: • Circinate impetigo:with peripheral extension of lesion & healing in the center.

  12. Crusted impetigo: • on the scalp complicating pediculosis. Occipital & cervical LNs are usually enlarged & tender.

  13. Ecthyma (ulcerative impetigo):adherent crusts, beneath which purulent irregular ulcers occur. Healing occurs after few wks, with scarring.

  14. Site:more on distal extremities (thighs & legs).

  15. Bullous Impetigo • Age: all ages, but commoner in childhood & newborn (impetigo neonatorum). • Site:face is often affected, but the lesions may occur anywhere, including palms & soles.

  16. The bullae are less rapidly ruptured (persist for 2-3 days) & become much larger. The contents are at first clear, later cloudy. After rupture, thin, brownish crusts are formed.

  17. Treatment of impetigo: • Treatment of predisposing causes:e.g. pediculosis & scabies. • Remove the crusts:by olive oil or hydrogen peroxide. • Topical antibiotic:e.g. tetracycline, bacitracin, gentamycin, mupiracin (Bactroban®), Fusidic acid (Fucidin®).

  18. Systemic antibiotics are indicated especially in the presence of fever or lymphadenopathy, in extensive infections involving scalp, ears, eyelids or if a nephritogenic strain is suspected, e.g. penicillin, erythromycin & cloxacillin. • Azithromycin (Zithromax®) 2 caps 500 mg daily for 3 days in adults. • In erythromycin-resistant S. aureus: amoxicillin + clavulanic a. (Augmentin®) 25 mg/kg/day.

  19. Folliculitis

  20. inflammatory disease of the hair follicles, which may be infectious or non-infectious.

  21. Superficial Folliculitis (Bockhart’s Impetigo)

  22. a dome-shaped pustule at the orifice of a hair follicle that heals within 7-10 days.

  23. Caused by staph aureus and affects mainly extremities and scalp. • Topical steroids are a common predisposing factor.

  24. Sychosis Vulgaris

  25. Recurrent red follicular papules or pustules centered on a hair, usually remain discrete over the beard or upper lip, but may coalesce to produce raised plaques studded with pustules. • DD: pseudofolliculitis of the beard, T. barae.

  26. Pseudofolliculitis

  27. from penetration into the skin of sharp tips of shaved hairs.

  28. Frunculosis (boils)

  29. It is a staphylococcal infection similar to, but deeper than folliculitis & invades the deep parts of the hair folliculitis. • Occasionally several closely grouped boils will combine to form a carbuncle. The carbuncle usually occurs in diabetic cases. The site of election is the back of the neck.

  30. Cellulitis & Erysipelas

  31. Cellulitis is an infection of subcutaneous tissues. • Ersipelas:It’s due to infection of the dermis & upper subcutaneous tissue by gp A streptococci. The organism reaches the dermis through a wound or small abrasion. It is regarded as a superficial “dermal” form of cut. cellulitis.

  32. Erythema, heat, swelling and pain or tenderness. • Fever and malaise which is more severe in erysipelas. • In erysipelas: blistering and hemorrhage. • Lymphangitis and lymphadenopathy are frequent.

  33. Edge of the lesion: well demarcated and raised in erysipelas and diffuse in cellulitis.

  34. Complications • Recurrences may lead to lymphedema. • Subcutaneous abscess. • Septicemia. • Nephritis.

  35. Treatment • Systemic antibiotics, especially penicillin, e.g. benzyl penicillin 600-1200 mg IV/6 hrs or cephalosporines. • Rest, analgesics.

  36. Skin diseases related to coryneform bacteria Erythrasma

  37. It is mild, chronic, localized superficial infection of skin by Coryn. Minutissimum. • Clinically: sharply-defined but irregular brown, scaly patches

  38. usually localized to groins, axillae, toe clefts or may cover extensive areas of trunk & limbs. Obesity & DM may coexist. • Coral red fluorescence under wood’s light.

  39. Treatment • Topical treatment with azole antifungal agents for 2 weeks or topical fucidin. • Erythromycin orally.

More Related