Lecture 12 - Skin, Soft Tissue and Eye Infections PDF

Lecture 12 — Skin, Soft tissue and Eye Infections Dr. Ed El Sayed NURS 342 Objectives Anatomy of skin layers Etiology of skin and eye infections Clinical presentation Diagnosis Treatment Most likely dx Best initial test Most accurate test What is the treatment Loading… I. Bacterial Infections Genera...

Lecture 12 — Skin, Soft tissue and Eye Infections Dr. Ed El Sayed NURS 342 Objectives Anatomy of skin layers Etiology of skin and eye infections Clinical presentation Diagnosis Treatment Most likely dx Best initial test Most accurate test What is the treatment Loading… I. Bacterial Infections General principles: 1. Skin infections caused by ß-hemolytic group A Streptococcus can cause glomerulonephritis BUT NOT heart infection some 2. Throat infections caused by ß-hemolytic group A Streptococcus can cause BOTH glomerulonephritis AND heart infection (rheumatic fever) m I 3. Skin infections is caused by Staphylococcus aureus BUT NOT Staphylococcus epidermidis (the latter is normal skin flora) 4. In cases of penetrating wounds/trauma, bacteremia with Staphylococcus epidermidis may occur L The 5 main descriptors of skin and wound lesions: 1. Calor — is the lesion warm? 2. Dolor — is the lesion tender? 3. Loading… Rubor — is the lesion red? 4. Fluor — is the lesion draining? 5. Tumor — is the lesion swollen? A. Impetigo epidermis Impetigo is the most superficial bacterial skin infection Mainly caused by Staphylococcus or Streptococcus invading the epidermis Usually seen in perioral region in children Clinical presentation is mainly crusting, oozing and draining of the skin Treatment is with topical mupirocin or retapamulin (prevent formation of bacterial proteins by inhibiting tRNA) Treat top Impetigo , w/ mupirocin or verapamulin B. Erysipelas Erysipelas is more severe than impetigo because it is an infection of deeper skin structures (i.e. dermis) can caused Much more commonly caused by Streptococcus than Staphylococcus but more in strep Clinical presentation is typically a bright red, hot and swollen lesion, mainly on the face - - TNWBL Can cause bacteremia, leukocytosis, fever and chills Untreated erysipelas is FATAL! chest S OB I pain HY10 Confusion Erysipelas pain- C. Cellulitis Tender = the all time fell painful when touched Cellulitis is an infection of the soft tissue of the skin which can extend from the dermis all the way down to the subcutaneous tissue It can occur any where, but it is more commonly seen in the lower extremities (i.e. legs more than arms) stender Clinically, the patient presents with fever and a warm, red, swollen skin that is painful to touch Staphylococcus and Streptococcus are the most common agents causing cellulitis ↓ focal , walled off , can pinpoint Not focal , All over A Unlike skin abscess, cellulitis does NOT have a collection of walled-off infection Deep vein thrombosis (DVT) can also present with warm, red, swollen skin that is painful to touch — so all patients suspected of having cellulitis MUST get doppler to exclude DVT after ruling only Out DUT Once DVT is ruled out, no further test is needed to confirm cellulitis — treat empirically Loading… Unilatera Need d NO doppleDut r clot such as thing Bilat :. cenulitis - Cellulitis D. Necrotizing Fasciitis Severe, life-threatening infection Starts as cellulitis that eventually dissects into the fascial planes of the skin, soft tissue and muscle Streptococcus and Clostridium are the most common bacteria associated with this condition because they produce toxins that worsens the disease -Perfinge Clinical presentation: High grade fever, severe pain, bullae (skin blisters filled with gas and liquid), crepitus (distinct sound resulting from friction between cartilage and bone) A Diagnostic tests include elevated CPK enzyme from muscle damage, and gas filled spaces on CT and MRI 3-anti-biotics Treatment: (vancomycin OR daptomycin) PLUS (carbapenem OR ß-lactam/ß-lactmase inhibitor combo) PLUS clindamycin (stops release of bacterial toxin) Untreated necrotizing fasciitis = DEATH! gas g E. Hair follicle infection Subdivided into 3 types based on size (folliculitis, furuncle and carbuncle) Folliculitis > Furuncle > Carbuncle There is no clear cutoff to determine the type — diagnosis is mainly based on clinical judgement Folliculitis is the smallest and mildest Furuncle is a small abscess (collection of infected material) Carbuncle is a collection of multiple furuncles Aside from pharmacological treatment, large furuncles and carbuncles can be surgically drained Treatment of bacterial skin infections Aside from impetigo (treated topically), hair follicle infections that are treated with drainage and necrotizing fasciitis (surgery plus combo systemic antibiotic regimens), the pharmacological treatment of the remaining skin infections is similar and based on severity: Not etiology Mild disease (no fever): Oral medications Start with penicillinase resistant ß-lactams (dicloxacilln) or cephalosporins (cephalexin) Penicillin allergic patients are treated with azithromycin MRSA infections are treated with delafloxacin, doxycycline or TMP/SMX 0x , clox , didlox , not ↳ macrloide azithros Clari Be > - Severe disease (fever, chills, bacteremia): * ery Fluroquinolone only one against MRSA Intravenous medications Start with penicillinase resistant ß-lactams (nafcillin) or cephalosporins (cefazolin) Penicillin allergic patients are treated with clindamycin qualible ↳ m as parentals for MRSA infections Vanco I dato ; left Groline -. - my lin mycin MRSA infections are treated with vancomycin, daptomycin or ceftaroline II. Fungal Infections In medicine, the proper name of superficial fungal infections is tinea, followed by the name of the body part (in Latin): Tinea corporis = body Tinea manus = hand Tinea pedis = foot Tinea cruris = groin (aka “jock itch”) The best initial test for fungal infections is potassium hydroxide (KOH) which will dissolve skin cells and kill bacteria leaving fungi intact The most accurate test for fungal infections is culture A. Tinea cruris Fungal infection that affects the groin, pubic region, and thigh Can be acute or chornic — the rash is asymmetrical Most common causes are Trichophyton rubrum and Epidermophyton floccosum Affects all sexes, with a male predominance More common in hot, humid climates and people who constantly sweat Obesity, smoking, diabetes tight underwear and friction between thighs exacerbate the disease Tinea infection in nails can spread to groin by scratching The buttocks and perineum can be involved — but there is sparing of the penis and vagina NO = Affected skin is hyperpigmented with clear demarcation around the edges Treatment is with maintaining clean skin in affected areas, not reusing towels m Emollients and skin creams and ointments to prevent friction, loose underwear - Topical anti-fungal drugs Treat topically & r Hyperac Treated B. Onychomycosis Fungal nail infection (Trichophyton rubrum) Onychomycosis of the fingernail is A oral Elesion treated for 6 weeks Onychmycosis of the toenail is treated * for 12 weeks Onychomycosis in patients with * diabetes or peripheral arterial disease increases the risk of cellulitis The most common type of onychomycosis is distal (patients with proximal onychomycosis are immunocompromised until proven that otherwise ↑ sceenor disease med curv or may From uzutich & Article immunocom Treatment of fungal skin infections Treatment depends on the location of infection: If no hair or nail involvement, topical antifungals are used (econazole, miconazole, ketoconazole) For infections involving hair or nails, oral drugs are used (terbinafine or b/c itraconazole) in liver down actione & * as think & enzyme that break druss All “-azole” antifungals are CYP450 inhibitors, so oral administration of these drugs are associated with numerous drug interactions Unique toxicities: -- Laghini androgen Ketoconazole is antiandrogenic — causes gynecomastia me have HE Itraconazole is contraindicated in heart failure More Terbinafine is contraindicated in liver disease -chron cirrhose from hep.. in women there will be never breast III. Mite Infection Scabies is an itchy rash caused by tiny insects called mites Scabies primarily involves the web spaces of the hands and feet, but can slow cause pruritic rash around the breasts and penis Itching can be EXTREME! The mite is small and cannot be easily seen with the naked eye, but the burrows they dig into skin is visualized Diagnosis is with scrapping the skin lesions after applying mineral oil in the burrows the force the mites out cause (NS ↓ toxicity Treatment is with permethrin (paralysis the mite), lindane is similar in efficacy but higher in -toxicity - Immunocompromised patients (e.g. HIV/AIDS, cancer/chemotherapy) are susceptible to a sever form of scabies called “Norwegian scabies” d Minera Nelpreout to s Oll Norwegian Scabies IV. Pubic Lice Phithirus pubis Six-legged lice that feeds on blood Transmitted through② non-penetrative sexual contact (primarily skin-to-skin in a low hygiene setting) Life cycle consists of three stages (egg, nymph, adult) The adult louse will die within 48 hours if no blood available for feeding Treatment (patient AND partner) is with topical * lindane (CNS toxicity, lowers seizure threshold) f O -- - Tree Do not forget to wash bedding, sheets m V. Toxin Mediated Skin Infections Toxic shock Syndrome (TSS) is caused by Staphylococcus attached to a foreign body (e.g. sutures, central lines, etc.) — this allows the bacterial to stay in the body longer and produce toxins TSS was historically associated with tampons (very rare) Loading… Clinical presentation includes high grade fever, low blood pressure (systolic BP Treatment: