Skin Infections Flashcards
What is the pathophysiology of cellultis?
- Cellulitis is a spreading bacterial infection of the dermis and subcutaneous tissues or fat
- Typically lasts 7-10 days
What are the causative organisms of cellulitis?
- The most common infective organisms in adults are Group A streptococci
- Strep. pyogenes
- Staph. aureus
- Less common organisms include
- Strep. pneumoniae
- Haemophilus influenzae
- Gram-negative bacilli
- Anaerobes
What predisposes someone to cellulits?
- Insect/spider bite
- Blistering
- Animal bite
- Tattoos
- Pruritic skin rash
- Surgery
- Athletes foot
- Eczema
- IV drugs
What are the signs and symptom of cellulitis
- Erythema that increases in size
- Irregular borders
- Hot to touch
- Swollen skin
- Pain
- General fever
- Tiredness
How should cellulitis be investigated?
- Clinical diagnosis
- Wound swab - C+S
- Ultrasound to rule out DVT
How should cellulitis be managed?
- Abx
- Cephalexin
- Amoxicilin
- Erythromycin
- Surgical drainage of abscess
- Sepsis 6
What are the possible complications of cellulitis?
- Sepsis
- Abscess
- Fascitis
What is impetigo?
- Impetigo is a common superficial bacterial infection of the skin that can cause sores and blisters.
- The condition is caused by bacteria entering the skin, usually through a cut or a break in the skin, like after an insect bite.
- Impetigo is extremely contagious, and is most common in young people, though anyone can develop the condition.
- The two main clinical forms are non-bullous impetigo and bullous impetigo
- Bullae are fluid filled lesions which are usually more than 5mm in diameter.
What are the causes of impetigo?
- Non-bullous impetigo is caused by:
- Staphylococcus aureus
- Streptococcus pyogenes
- Or a combination of both and accounts for the majority of cases (about 70%).
- Bullous impetigo is caused by:
- Staphylococcus aureus
- Impetigo caused by Meticillin-resistant Staphylococcus aureus (MRSA) is becoming increasingly common.
Outline the pathophysiology of impetigo
- Involves superficial layers of the skin
- Spreads directly skin to skin contact
- Duration <3 weeks
What are the signs and symptoms of impetigo?
- Often begins as a red sore near the nose or mouth
- Painful itchy yellowish crusts
- Lymphadenopathy
How is impetigo investigated?
Clinical diagnosis
How should impetigo be managed?
- Antibiotics
- Cephalexin
- Topical Antibiotics
- Mupirocin
- Fusidic acid
What are the possible complications of impetigo?
- Cellulitis
- Post-streptococcal glomerulonephritis
What cases folliculitis?
- Bacterial - staph aureus (head)
- Fungal - tinea barbae (chest)
Outline the pathophysiology of folliculitis
- Chronic infection of hair follicles, can also be damaged
What are the signs and symptoms of folliculitis?
- Small red bumps
- White headed pimples
- Itchiness
How shuld folliculitis be managed?
- Topical antiseptic (tea tree oil)
- Topical antibiotic
- Fungal - fluconazole
What are the complications of folliculitis?
- Abscess (furuncle or carbuncle)
What are erysipelas?
- Erysipelas is an acute infection typically with a skin rash, usually on any of the legs and toes, face, arms, and fingers.
- It is an infection of the upper dermis and superficial lymphatics,
- Erysipelas is more superficial than cellulitis, and is typically more raised and demarcated.
What are the causes of erysipelas?
- Group A beta-hemolytic Streptococcus bacteria on scratches or otherwise infected areas.
- Strep pyogenes
Outline the pathophysiology of erysipelas
- Involves an infection of the upper dermis and the sympathetic lymphatic tissue
- The rash is due to endotoxins from the microorganism
- The bacteria can enter through broken skn and nasal passages
What are the signs and symptoms of erysipelas?
- Erythema
- Well defined raised borders
- Warm
- Pain
- Fever
- Shaking
- Chills
- Fatigue
- Headaches
- N+V
- Lymphadenopathy
How should erysipelas be managed?
- Antibiotics oral and IV
- Penicilin
- Erythromycin
