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Bacterial infections
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- 2. • Staphylococcus Aureus •Coagulase-negative Staphylococci, • Bacillus Anthracis • Corynebacterium Diphtheriae • Anaerobic Diphtheriods (P.Acnes) • Aerobic Diphtheroids (C.Minutissimum) • Clostridium Perfringes • Borrelia Burgdorferi • Bartonella Henselae & B.Quintana Gram-positive bacteria
- 3. • Meningococcal infection •Gonococcal infection • Acinetobacter infection • Moraxella infection • Chancroid • Salmonella infection • Pseudomonas infection • Rhinoscleroma • Tularaemia • Pasteurella infection • Plague and Yersinia infections • Brucellosis • Infections due to Bartonella spp • Ehrlichiosis
- 4. Anaerobic bacteria • Tropicalulcer • Granuloma inguinale Actinomycete infections • Actinomycosis, • Nocardiosis Others • Spirochaetes and spiral bacteria • Botryomycosis • Necrotizing subcutaneous infections • Mycoplasma infections • Chlamydiae • Rickettsial infections • Dermatoses possibly attributable to bacteria
- 5. Involvement of Staphylococcusaureus in cutaneous disease Direct infection of skin and adjacent tissues • Impetigo • Ecthyma • Folliculitis • Furunculosis, • Carbuncle • Sycosis • Occasionally in cellulitis, • Others Secondary infection • Eczema, infestations, ulcers, etc. Cutaneous disease due to effect of bacterial toxin • Staphylococcal scalded skin syndrome • Toxic shock syndrome • Staphylococcal scarlatina
- 6. Involvement of streptococci(mostly group A) in cutaneous disease. Direct infections of skin or subcutaneous tissue • Impetigo • Ecthyma • Erysipelas • Cellulitis • Vulvovaginitis • Perianal infection • Streptococcal ulcers • Blistering distal dactylitis • Necrotizing fasciitis • Others Secondary infection • Eczema, infestations, ulcers, etc. Tissue damage from circulating toxin • Scarlet fever • Toxic shock-like syndrome Skin lesions attributed to allergic hypersensitivity to streptococcalantigens • Erythema nodosum • Vasculitis Skin disease provoked or influenced by streptococcal infection (mechanism uncertain) • Psoriasis, especially guttate forms
- 7. IMPETIGO • Impetigo isa contagious superficial pyogenic infection of the skin • Bullous and Nonbullous. Bullous impetigo - S. aureus. Non Bullous - S. aureus and less often by group A streptococcus, or by both organisms
- 8. • In non-bullousimpetigo, the initial lesion is a very thin-walled vesicle on an erythematous base. • The vesicle ruptures rapidly into a honey- colored crusted plaque • Face, esp around nose & mouth, limbs • Constitutional symptoms & regional adenitis + • >70 percent of cases of impetigo • occurs in children of all age
- 9. • In bullousimpetigo, the bullae are less rapidly ruptured and become much larger • persist for 2 or 3 days. • After rupture thin, flat, brownish crusts are formed. • Although the face is often affected, the lesions may occur anywhere • The buccal mucous membrane may be involved. • Regional adenitis is rare • 10% Pediatric diseases • can also occur in adults
- 10. • Diagnosis basedon clinical appearance • Aspiration of blister fluid for gram stain and cultures • Treatment : antibiotics
- 11. STAPHYLOCOCCAL SCALDED SKIN SYNDROME •A syndrome which is a generalised exanthematous disease consisting of cutaneous tenderness and widespread superficial blistering and denudation • Common in infants / children , also in adults • Risk factors for adults : - compromised immune response , malignancy - Renal insufficiency - Alcohol abuse
- 12. • exanthem oruniform erythema sparing mucosal surfaces • cutaneous tenderness – early stage • Perioral and flexural exanthema • Purulent conjunctivitis , Otitis media , Nasopharyngeal infection or pyogenic skin infection • Large flaccid bullae , Nikolsky`s sign • Superficial tissue paper like wrinkling of Epidermis
- 13. • Toxic features •Resolves spontaneously • Healing complete – 5-7 days • C/s ( intact blister ) - sterile Treatment • Uncomplicated cases : Oral antibiotics with fluid and electrolyte management • Neonates – incubators to maintain body temperature and humidity • Use of non adherent dressings (petroleum impregnated gauze) to superficial blistering areas with mupirocin application
- 14. Toxic shock syndrome •Fever , rash followed in 1-3 weeks by desquamation , circulatory shock and mutisystem involvement mediated by one or more toxins elaborated by Staphylococcus aureus. • TSST – 1 • ENTEROTOXINS B & C - post surgical & burn wounds,sinusitis, Osteomyelitis, Influenza,IV drugGynecologic infections Rx Supportive and focused on eradicating the offending S.aureus • Antistaphyloccal antibiotics • Avoidance of tampoons , diaphragms and contraceptive sponges
- 15. ECTHYMA • Ecthyma isa pyogenic infection of the skin characterized by the formation of adherent crusts, beneath which ulceration occurs. • consequence of neglected impetigo. • S. aureus and/or grp A streptococcus can be isolated on culture • Poor hygiene and neglect are key elements in pathogenesis.
- 16. • Small bullaeor pustules on an erythematous base are soon surmounted by a hard crust nof dried exudate • increases in size by peripheral accretion. • The base may become indurated and a red oedematous areola is often present. • The crust is removed -reveals a purulent irregular ulcer. • Healing occurs after a few weeks, with scarring. • The buttocks, thighs and legs are most commonly affected. Treatment. • Improved hygiene and nutrition • treatment of other underlying disease, • The antibiotic chosen should be active against both Streptococcus pyogenes and Staphylococcus
- 17. • Cellulitis isan acute, subacute or inflammation of subcutaneous tissue in which an infective, generally bacterial, cause is proven or assumed. • Most commonly: Staph • Erysipelas is a bacterial infection of the dermis and upper subcutaneous tissue; • its hallmark is a well- defined, raised edge reflecting the more superficial (dermal) involvement. • Most commonly: Strepto
- 18. Folliculitis • This isa pyoderma that begins within the hair follicle • classified according to the depth of invasion • superficial and deep,
- 19. Superficial folliculitis • Subacuteor chronic folliculitis, in which the inflammatory changes are confined to the ostium or extend only slightly below it, • heals without scar formation, • Infective, physical & chemical injury • A small fragile dome-shaped pustule • Often on the scalps of children and in the beard area, axillae, extremities, and buttocks of adults.
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- 21. Deep folliculitis(Sycosis barbae) •Deep folliculitis with perifollicular inflammation occurring in the bearded areas of the face and upper lip • Untreated -the lesions may become more deeply seated and chronic. • Local Rx with warm saline compresses and local antibiotics (mupirocin) sufficient to control infection. • More extensive cases require systemic antibiotic therapy.
- 22. Furuncles • Deep-seated inflammatorynodule that develops about a hair follicle • usually from a preceding superficial folliculitis and often evolving into an abscess. • hair-bearing & sites prone for friction, occlusion, and perspiration, such as the neck, face, axilla & buttocks. • complicate preexisting lesions such as atopic dermatitis, excoriations, abrasions, scabies, or pediculosis, but occur more often in the absence of any local predisposing causes
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- 24. Host factors associatedwith furunculosis: • obesity, blood dyscrasias, defects in neutrophil function, Rx with glucocorticoids and cytotoxic agents, and immune globulin deficiency states, DM • Starts as a hard, tender, red folliculocentric nodule in hair-bearing skin that enlarges and becomes painful - Rupture occurs, with discharge of pus and often a core of necrotic material. • Solitary/multiple
- 25. • A carbuncleis a deep infection of a group of contiguous follicles with Staphylococcus aureus, accompanied by intense inflammatory changes in the surrounding and underlying connective tissues, including the subcutaneous fat. • occur predominantly in men, and usually in middle or old age • more common in the presence of diabetes, malnutrition, cardiac failure, drug addiction or severe generalized dermatoses, such as exfoliative dermatitis or pemphigus, and during prolonged • steroid therapy. Carbuncle
- 26. • The termcarbuncle is derived from the Latin word for a small, fiery coal, describes the painful, hard, red lump that is the initial stage of the infection. • Suppuration begins after 5–7 days, and pus is discharged from the multiple follicular orifices. • Necrosis leaves a yellow slough surmounting a crateriform nodule. • the nape of the neck, the back, or thighs • Fever and malaise +
- 27. Erysipelas Acute inflammation ofskin & subcutaneous tissue caused by streptococci Onset- abrupt Symptoms: Pain, fever chills Signs: Tense, bright red oedematous sharply demarcated smooth hot area Complications: Skin necrosis, sub cutaneous abscess, septicaemia Treatment: - Treatment of underlying factors - Local, sisomycin, fusidic acid nupirocin - Systemic Ensamycin, Cephalexin, Cefadroxil, Azithromycin
- 28. Coryneform bacteria • Erythrasmais a mild, chronic, localized superficial infection of the skin caused by Corynebacterium minutissimum. • occurs most commonly in the groins, axillae and the intergluteal and submammary flexures. • Coral-red fluorescence with Wood’s light is attributable to coproporphyrin III
- 29. • Pitted keratolysis:Asuperficial infection of the skin apparently caused by a species of Corynebacterium and producing circular erosions on the soles
- 30. Actinomycosis • A chronic,spreading suppurative and granulomatous disease caused primarily by Actinomyces israelii: • draining sinuses are formed through which the characteristic sulphur granules are discharged • five main clinical types depending on the primary site of infection; namely, cervicofacial (lumpy jaw), thoracic, abdominal, primary cutaneous and pelvic.
- 31. • Cultures: appearafter anaerobic incubation at 37°C for 2–4 days on enriched media (brain– heart infusion glucose agar) • white, glistening, nodular colonies with somewhat irregular margins Treatment : • Penicillin • Surgical debridement