PHTH1012 009 Skin and Wound Infections - Rodriguez.pdf

PRESENTER : CAMILLE-ANN THOMS-RODRIGUEZ MBBS DM  Definition of  skin infection  wound infection  The skin as an organ of the body and its functions  To discuss some common skin and wound infections (causative agent; lab dx and treatment will be emphasized)   SKIN INFECTIONS :  Impetigo  Fol...

PRESENTER : CAMILLE-ANN THOMS-RODRIGUEZ MBBS DM  Definition of  skin infection  wound infection  The skin as an organ of the body and its functions  To discuss some common skin and wound infections (causative agent; lab dx and treatment will be emphasized)   SKIN INFECTIONS :  Impetigo  Folliculitis  Furuncles/Carbuncles  Cellulitis  Paronychia  Necrotizing fascitis  Gas gangrene  Leprosy  Lupus vulgaris  Chicken pox  Scabies WOUND INFECTIONS  Decubitus ulcers  Invasion by and multiplication of pathogenic microorganisms in in the skin which results in subsequent tissue injury.  While a skin infection may cause inflammation, a skin infection should not be defined as inflammation of the skin secondary to an infectious process.  Broad  definition: Invasion into and multiplication of micro-organisms (usually bacteria) in a break in the skin caused by physical injury from trauma (GSW, stabs, surgical site infections) SSI, DFI etc)  In the strictest sense a wound infection is a surgical site infection (SSI) A wound infection is a skin infection  Largest organ of the integumentary system  FUNCTIONS OF THE SKIN  Protection: barrier; Langerhans cells in the skin are part of the adaptive immune system.  Sensation via nerve endings  Thermoregulation  Control of fluid loss  Storage and synthesis- acts as a storage center for lipids and water  Absorption - in humans a few outer skin cells are almost exclusively supplied by external oxygen  Water resistance (nutrients are not washed away)  Bacterial    Fungal  Superficial-Pytiriasis versicolor ‘liver spots’  Cutaneous- Dermatophytosis; Candidiasis  Sub-cutaneous- e.g. Sporotrichosis  Systemic-Candidiasis, histoplasmosis Parasitic   Bacterial skin infections include:  Impetigo  Erysipelas  Cellulitis Eg Scabies Viral  Measles  Chicken pox Impetigo Definition Impetigo is an initially vesicular, later crusted superficial infection of the skin. Aetiology Staphylococcus aureus - dominant microorganism in all forms of impetigo [occasional studies may implicate group A streptococcus as the major cause] Group A streptococcus (streptococcus pyogenes). Nonpurulent complications with nephritogenic strain causing post-streptococcal glomerulonephritis Mixed Staph. and Strep. Characteristics A. Simple superficial impetigo/nonbullous eruption/impetigo contagiosa Indolent, well-tolerated, lesions on exposed areas, typically beginning at traumatized sites. Erythematous papules !crusted forms (amber or honey - coloured). B. Bullous impetigo Superficial bullae from - normal - appearing skin,varies from thin and translucent !cloudy or purulent. Rupture - flat, thin, varnish-like coatings. Symptoms Red, tender nodule on arms, legs or face Rapid spreading of lesions Weeping shallow red ulcer Honey-coloured crusts Blistering, especially on buttocks, trunks and face May be concentrated around mouth Signs Superficial, vesiculopustular eruption, different stages Erythematous tender papule Honey-coloured crusts Regional lymphodenopathy (absent in bullous impetigo). Differential Diagnosis Nonbullous eruption Bullous eruption Chicken pox Herpes Folliculitis Erysipelas Insect bites Eczematous dermatitis Scabies Tinea corporis Burns Pemphigus vulgaris Bullous pemphigoid Stevens-Johnson syndrome Suggested Workup 1. Clinical diagnosis 2. History - mainly in children, especially 2-5 year old 3. Collect exudate - weeping ulcer or unroof crust - gram stain and culture Coagulase-positive Staphylococcus, Beta-hemolytic Streptococcus Suggested Treatment 1. Topical antibiotics therapy Most infections (without bullous eruptions) Mupirocin (bactroban) 2% ointment t.i.d. for 7 to 10 days Suggested Treatment cont’d: 2. Systemic antibiotic therapy. Indications are: widely disseminated or inaccessible lesions outbreaks - family, daycare bullous impetigo Suggested Treatment contd: No response to mupirocin after 3 to 5 days Augmentin - all for 10 days Cefaclor Cephalexin 3. Penicillin allergy Cephalexin - NOT erythromycin Patient Education Debridement of crust - wet soaks for 20 minutes tid followed by gentle scrubbing Short fingernails; no scratching; strict hand washing by affected persons Antibacterial soap; do not share towels and washcloth children removed from daycare until 24 hours of antibiotic Definition Folliculitis is a pyoderma located within hair follicle. The lesions consist of small (2-5 mm) erythematous, sometimes pruritic, papules often toped by a central pustule Aetiology Staphylococcus aureus Pseudomonas aeruginosa (‘Hot tub folliculitis’) Symptoms Painful, red ‘bumps’ around hairs Most common on face, limbs or scalp No systemic symptoms or fever Occasionally pruritic Signs Yellow or gray pustules Lesions are commonly grouped Differential Diagnosis Contact dermatitis Tinea Acne Flat warts Suggested Treatment 1. Inflammation without infection a. Cleanse with antibacterial soap b. Moist heat 2 to 3 times a day 2. Inflammation with suspected infection unknown etiology Mupirocin 2% ointment t.i.d. x10/7 of Suggested Treatment Cont’d 3. S. aureus infection Cloxacillin 4. Pseudomonas aeruginosa a. Ciprofloxacin b. Ofloxacin Definition A furuncle is a deep inflammatory nodules usually developing from a preceding folliculitis. A carbuncle is a deep seated infection or multiple hair follicles that coalesce and spread into the subcutaneous tissues, frequently associated with sinus tracts. Aetiology Staphylococcus aureus Symptoms & Signs Furuncles 1. A firm, tender, red nodule that soon becomes painful and fluctuant 2. Spontaneous drainage ----> lesion subsides Carbuncles (symptoms) 1. Larger, deeper indurated, serious lesion 2. Fever and malaise --->acutely ill. Signs 1. Erythematous perifollicular swelling 2. Papules or nodules: 1 to 5 cm 3. Pustular discharge from necrotic plug Suggested Workup 1. Physical examination - clinical diagnosis 2. Collect exudate for gram stain and culture 3. Blood culture if septic Suggested Treatment 1. Local, topical care: a. Moist, warm compresses 30 min 4 times daily b. Incise and drain - heart lesions given antistaphylococcal prophylaxis 2. Systemic antibiotics reserved for: a. Furuncles in the nose or central facial areas b. Fever c. Extensive surrounding cellulitis d. Treat with cloxacillin or penicillin allergy erythromycin for 14 days Differential Diagnosis Contact dermatitis Tinea,Acne,Flat warts - Definition Cellulitis is a superficial, spreading, warm erythematous inflammation of the skin and subcutaneous tissues. Arise from: a. Entry via disruption (eg. a laceration, puncture wound or fungal intertrigo) b. Extension from a contiguous focus (i.e. an abscess) Aetiology 1. Group A streptococcus and Staphylococcus aureus 2. Invasive group A streptococcus a. Pain b. Erythema, oedema, and bullae c. Immature granulocytes, lymphopenia, hypoalbuminemia and hypocalcemia Aetiology cont’d 3. Group B streptococci 4. H. influenzae 5. Pseudomonas aeruginosa a. Vesicles and bullae b. Ecthyma gangrenosum c. gangrenous cellulitis d. macular or maculopapular lesions Symptoms 1. After several days, local tenderness, pain, swelling and erythema, rapidly intensify and spread 2. Fever, chills and malaise 3. Itching (facial cellulitis) 4. Foul-smelling discharge from site Signs 1. Extensive, lesion is very red, hot and swollen 2. Margins of lesion not elevated and sharply demarcated 3. Regional lymphadenopathy, + bacteremia 4. + local abscesses, skin necrosis Definition Inflammation involving the folds of tissue around the fingernail Aetiology 1. Staphylococcus aureus 2. Group A streptococcus 3. Candida 4. Pseudomonas aeruginosa Symptoms 1. Pain and inflammation 2. Post trauma or frequent immersion into water 3. Acute or chronic Signs 1. Erythematous swelling of skin around a plate 2. Purulent discharge 3. Regional lymphangitis nail I & D if necessary  Empiric then Cx directed  Supportive care Definition Asevere soft tissue infection marked by edema and necrosis of subcutaneous tissues with involvement of the fascia and widespread undermining of adjacent tissue 1.Group A Streptococcus 2. Staphylococcus aureus  edema  necrosis of subcutaneous tissues  involvement of the fascia  polymorphonuclear leukocytosis  DX Clinical  Laboratory-specimen for culture and susceptibility testing   MX Early empiric antibiotics and then Cx directed  Early surgical intervention with debridement  Contact pecautions  A life and death emergency  Caused by C. welchi aka C. Perfringens  Signs  Crepitations  Wet gangrene   Dx Clinical  Lab     Samples from debridment can be sent for Cx Blood Cx Mx High dose penicllin/metronidazole  Emergency Sx for amputation/debridement  Supportive care  rehabilitation   Also  An known as Hanson disease infectious disease, cause Mycobacterium leprae.  Characterized by disfiguring skin lesions, peripheral nerve damage ,and progressive debilitation  Difficult disease to transmit ,and has a long incubation period. Children more susceptible.  Two common forms, tuberculoid and lepromatous  Both forms produce lesions on the skin, but the lepromatous form is more severe ,producing large disfiguring nodules,  The disease causes sensory loss in the skin and muscle weakness.  Long term leprosy may result in loss of use of hand and feet due to repeated injury due to lack of sensation.  Hypopigmented skin lesion that have decreased sensation to touch ,heat, or pain.  Skin lesions that do not heal after several weeks to months.  Numbness or absent sensation in the hands and arms or feet and legs.  Muscle weakness resulting in signs such as footdrop  Only the lepromatous form is thought to be infectious.  Exposure to the nasal discharge of those that remain untreated for years is thought to be the main cause of infection.  Most persons are immune to leprosy  Transmission is not completely understood.  Exposure to insect vectors and infected soil has been suspected.  Household contacts of patients are at little risk of acquiring the disease.  This is tuberculosis of the skin, appears first on the face and heals slowly leaving deep scars.  More common in underdeveloped nations and in the immunosuppressed.  The lesion spreads with hyperpigmented margin and a hypopigmented core,  Caused by infection with Mycobacterium tuberculosis  Systemic features may occur include: night sweats, weight loss, malaise ,fever anorexia. The disease may be asymptomatic.  Skin: erythema nodosum, erythema induratum lupus vulgaris. A chronic ,progressive & tissue-destructive form of cutaneous tuberculosis in patient with moderate or high degree of immunity.  Occurs more common in females.  The lesions progress by peripheral extension and central healing, atrophy and scarring.  the areas of predilection are head and neck (80%) followed by arms & legs, then trunk.  It can be associated with tuberculosis of lymph node, lung bone and joint.  In long-standing cases ,patients may have scarring, deformity, squamous cell carcinoma, basal cell carcinoma or sarcoma. CHICKEN POX  Causative Agent Varicella Zoster Virus  Highly contagious   Clinical      features Incubation period -14 to 16 (10-21)days A mild prodrome of fever and malaise may occur 1 to 2 days before rash onset red papules; vessicles; crusts and scabs PURITIC! Infection lasts 5-10 days  Complication/sequale-shingles  Dx Mainly clinical  Lab dx:     Vessicle fluid for viral culture ELISA Other  Management Supportive  Antivirals (eg valcyclovir-for high risk pt)   Control Barrier precautions  Vaccine - have you gotten yours?   Caused  by Sarcoptes scabiei (mite) Highly contagious  Clinical features Itching  Papules  burrows   Dx Mainly clinical  Lab dx   MX Permithrin  Lindane  supportive  Definition Decubitus ulcers are cutaneous ulcerations caused by prolonged pressures that results in ischemic necrosis of the skin surface and underlying soft tissue. Aetiology 1. Pressure 2. Friction 3. Shear forces Aetiology cont’d 4. Moisture 5. Contributing factors-: a. Decreased mobility b. Decreased sensation c. Poor nutrition d. Dementia Most common organisms include: staphylococci, streptococci, coliforms and a variety of anaerobes. Symptoms 1. Pain - stage 1 or 2 2. Pain free - stage 3 or 4 Signs 1. Erythema 2. Exudate 3. Ulcer crater 4. Necrotic tissue Choose one skin infection and for that infection list/describe:  The aetiological agent  Mode of transmission  The clinical features  Diagnosis  Treatment