View
217
Download
0
Category
Preview:
Citation preview
Skin Infections
Classification of pyodermas 1. Primary
Impetigo
Ecthyma
Folliculitis
– Superficial
– Deep * Folliculitis of leg
* Furuncle
* Carbuncle
* Sycosis Barbae
Skin Infections
• Cellulitis/ Erysipelas
• SSSS
• TSS
2. Secondary
Secondary infection of preexisting dermatoses
eg. Atopic dermatitis, Scabies
Bacterial Skin Infections
• Very common
• Range from annoying to deadly infections
• Mostly caused by Staph aureus and Strep
Bacterial Skin Infections
• Folliculitis – Infection of hair follicle
– Usually heals without scarring
– Caused by Staph aureus
– Tx: Warm saline compresses. If does not resolve spontaneously in 1- 2 weeks, topical mupirocin. Oral cloxacillin ( very rare)
Young male presenting with pruritic erythematous macules that progressed to papules and pustules
folliculitis
Staph Skin Infections
• Furuncle/Boil
– Infection of pilosebaceous unit (hair follicle and
surrounding tissue)
– Usually must drain before they heal – takes less than 2 wks
– Complicated boils – over middle of face/ spine or with fever
Staph Skin Infections
• Carbuncle
– Several furuncles that are densly packed together
– Common in diabetics
– Tx : severe cases, first I&D
– Oral antibiotics (cloxacillin), or cephalexin if fever
Staphylococcal scalded skin sydrome (SSSS)
• Exotoxin of staph (Phage Group II)
• Acantholysis
• Occult staph. upper respiratory tract infection or
purulent conjunctivitis
• Infants and children
• Tender red skin
Acute Paronychia
– Infection of lateral and posterior nail fold
– Most common pathogen Staph aureus
– Results from nail biting, finger sucking, excessive manicuring or penetrating trauma
– Conservative tx: Warm soaks/ oral antibiotics ( clindamycin, augmentin)
– If abscess or fluctuance is present, spontaneous drainage / incision and drainage.
– I & D: blade is directed away from the nail plate
Impetigo
• Non-bullous – principal pathogen is Staph aureus
• Group A beta hemolytic strep minority of cases
• Bullous form is nearly caused by Staph aureus (common in infants and children < 2yrs)
• Honey crusted lesions/large vesicles
Impetigo (cont…)
• Tx: topical mupirocin as effective as oral antibiotics – Oral antibiotics for nonlocalized cases - cloxacillin,
1st gen cephalosporin, augmentin.
– Macrolides not adequate given increasing resistance.
• Complication: Strep glomerulonephritis
• Nasal carriage, source for reccurrence, tx - topical mupirocin
• Very contagious, appropriate hygiene for prevention
Cellulitis
• Painful erythematous infection of dermis and subcut tissue
• Beta hemolytic strep , may be combined
with staph (MRSA on the rise) Commonly occurs near skin breaks, such as
trauma, surgical wounds, tinea infections( in diabetics)
• Tx: 1st gen cephalosporins, augmentin – Limited disease(oral treatment), extensive
disease requires parenteral treatment – I&D if fluctuant
• May turn into necrotizing fascitis – medical emergency
MRSA Infections
• Community acquired – MRSA – in children in daycare – Athletes – Military recruits
• Healthcare associated –MRSA • Resistant to multiple antibiotics, send for C&S • Tx : CA- MRSA :Clindamycin, Doxycycline, Bactrim,
Vancomycin HA-MRSA : Vanc, Linezolid • Recurrence very common • Prevention: personal hygiene is the key
– Wash hands !! – Do not share personal items – Cover all open wounds
Erythrasma
• Results in pink patches to brown scales, may be pruritic. Lichenification and hyperpigmentation common
• Caused by Corynebacterium minutissimum
• Commonly found in intertriginous areas/ toe webs
• Prevalent among diabetics, obese, and in warm climates, worsened by wearing occlusive clothing
• DDx: tinea, acanthosis
• Dx: KOH neg, Wood’s lamp : coral pink fluorescence
• Tx: oral erythromycin 1-2 weeks
• Abx soap to prevent recc
Viral warts/Condylomas/Squamous cell papillomas/ Verrucae
• Small, rough tumor w/ cauliflower surface or solid blister
• Hands, feet, genital areas
• Caused by HPV – 6 & 11 serotypes
• Tx : topical irritants – Salicylic acid, podophyllin, cantharidin,trichloroacetic
acid
– Destructive methods: cryo, electro, laser excision/curretage
• Prevention: Gardasil vaccine
Herpes simplex infections
• Mucocutaneous: prodrome followed by grouped tensed vesicles over an erythematous base
• Herpetic gingivostomatitis in children • H.labialis/cold sores/Whitlow – caused by HSV 1 • Genital herpes : usually caused by HSV2 • Dx: clinical, if atypical lesion: Tzanck , PCR, Culture,
serology • Tx: acyclovir, valacyclovir: reduce viral shedding and
duration of sx during primary infection • Recc infection: tx with beginning of the first symptom • Frequent eruptions( >6/yr) should receive daily supressive
tx • Herpetic whitlow, no I & D ( risk of bact superinfection or
systemic spread.
Molluscum contagiousm
• Caused by pox virus, MCV
• Flesh colored, dome shaped,pearly w/ typical central umbilication
• Common in children
• Autoinoculation spreads to neighboring areas
• Tx: self resolving sometimes or cryotherapy( using liquid nitrogen)
Hand foot and mouth disease
• Caused by Coxsackie A16, member of enterovirus family
• Tender blisters, fever, sore throat, ulcers in throat,
loss of appetite
• Children under 10 yrs of age • Spread by person to person • Outbreaks in summer and early fall • Symptomatic tx: prevent dehydration
CLASSIFICATION OF CUTANEOUS TUBERCULOSIS
TRUE CUTANEOUS TUBERCULOSIS TUBERCULIDES
EXOGENOUS ENDOGENOUS HEMATOGENOUS
• Tuberculosis chancre
• Scrofuloderma • Acute miliary TB • Papulonecrotic tuberculide
• Warty TB (verrucosa cutis)
• Peri-orifial tuberculosis
• Lupus vulgaris • Lichen scrofulosorum
• Lupus vulgaris • Tuberculous gumma • Erythema induratum of Bazin
• Nodular phlebitic tuberculid
Recommended