Skin, Soft Tissue, Bone and Joint Infections Flashcards
What do the clinical manifestations of skin and soft tissue infections include?
Erythema Warmth Tenderness Systemic symptoms - Chills - Fever
What is the differential diagnosis for unilateral leg erythema, swelling, and tenderness, of rapid onset?
DVT Cellulitis Localised infection Eczema/contact dermatitis Compartment syndrome Necrotising fasciitis
What is the relevance of cracked heels and tinea between the toes in skin and soft tissue infections?
Candida and cracked skin allow entry of bacteria into dermal layer
What is cellulitis?
Acute inflammatory process involving skin and soft tissues
What are the features of cellulitis?
Spreading, erythematous rash
Most cases involve lower limbs
Almost always unilateral - if not, limbs have different pattern
Chills and fevers may precede localising symptoms and signs
Red, warm, tender rash
Often associated with lymphangitis
What can happen in severe or protracted cellulitis?
Abscess - rare
Bullae
Vesicles
What are the risk factors for cellulitis?
Lymphatic stasis Peripheral oedema - with skin breaches Trauma IV drug use Ulcers Wounds Dermatophytic infections
What pathogens usually cause cellulitis?
Group A Streptococcus - Potential to rapidly go to necrotising fasciitis - Most likely cause Other Strep Staph aureus Coagulase -ve Staph
How is cellulitis diagnosed?
Usually clinical - epidemiology and history important clues to underlying microbiology Swab pus, if present Blood cultures indicated for - Fever - Extensive cellulitis - Immunosuppression - Lack of response to empiric therapy - Suspicion of unusual pathogen
When is imaging helpful in the diagnosis of cellulitis?
Ultrasound to differentiate DVT
MRI/CT if suspicion of necrotising fasciitis/pyomyositis
Which pathogens are likely to cause skin infections in IV drug users?
Typical cellulitis pathogens
Oral flora
Which pathogens are likely to cause skin infections post burns?
Typical pathogens
Pseudomonas aeruginosa
Enterobacteriaeciae
Acinetobacter spp
Which pathogens are likely to cause skin infections in immunocompromised hosts?
Typical pathogens Gram -ve bacteria Fungi Viruses Mycobacteria
Which pathogens are likely to cause skin infections in seawater exposure?
Vibrio spp
Which pathogens are likely to cause skin infections in freshwater or mud exposure?
Aeromonas spp
Mycobacterium marinum
Which pathogens are likely to cause skin infections due to dog or cat bites?
Typical pathogens
Oral Streptococci
Oral anaerobes
Which pathogens are likely to cause skin infections due to human bites?
Typical pathogens
Oral flora
What is the management of cellulitis?
Oral preparations Di/flucloxacillin - Good for Staph and Strep - Doesn't cover MRSA, Gram -ves, anaerobes Penicillin - Staph pyogenes cultured/suspected Cephalexin - For hypersensitivity to penicillins
For whom should IV antibiotics in the treatment of cellulitis be reserved?
High fever
Systemic toxicity
Facial cellulitis
How long does cellulitis take to resolve?
7-10 days to start
2 weeks to fully
Therefore don’t need to treat with antibiotics until redness gone
What is the adjunctive and preventative management for cellulitis?
Management of lower limb ulcers and oedema/venous insufficiency - Dressings - Compression stockings - Leg elevation - Diuretics Keep skin hydrated = emollients Assess for and manage tinea pedis
What is chronic lymphoedema?
When lymphatic load exceeds transport capacity of lymphatic system
What are the risk factors for chronic lymphoedema?
Trauma, especially recurrent Malignancy, and its treatment - Keep in people who've had all lymph nodes removed in arm Chronic venous insufficiency Obesity Inflammatory disorders
What are the features of chronic lymphoedema?
Tight, swollen legs > discomfort
Chronic condition compared to cellulitis
May become super-infected
