Infections Flashcards
What is this?
What is its pathology?
Herpetic Whitlow
Viral infection of the finger by Herpes Simplex 1- HSV1
Who is hepetic whitlow common in?
What is its pathphysiology?
Dental / medical personnel
Commonly effects toddlers and preschool children
viral shedding occurs with vesicles forming bullae
What are the symptoms and signs of someone with herpetic whitlow?
Intense burning then erytherma, malaise
O/e= erytherma then small vesicular rash
over 2 weeks vesicles may merge to -> bullae
Fever and lymphadenitis
How is hepetic whitlow confirmed?
TZANK smear
Diagnosis confirmed by culture, antibody titers or Tzank smear
How is this treated?
What are the complictions?
1) Non operative and Acyclovir
standard tx- resolution 7-10 days
acyclovir may reduce time of symptoms
2) Operative = AVOID as- associated with superinfections, encephalitis and death!!
Complications include SUPERINFECTIONS- may require further antibiotics oral- pencillinase resistance for 7-10 days
What is this?
What is its incidence?
What is it’s pathology?
Paronychia
Most common hand infection- children and women (3:1 cf males)
Most commonly affects the thumb
Break in seal between nail fold and plate allows bacteria to gain entry- result of nail biting or manicures
What is the common organism in acute and chromic paronychia?
ACUTE
Adults- Staphyloccus aureus
Children/ Diabetics**-mixed oropharyneal **
CHRONIC
Candida albicans- common diabetics, often unresponsive to antibiotics
What are the causes of acute paronychia?
Nail biting
Manicures
Thumb sucking
What are the causes of Chronic paronychia?
What are the risk factors for developing chronic paronychia?
Occupational exposure to water and irrants acid/alkali
RF= Diabetes
Psorasis
Steroids
Retroviral drugs- Indinavir= HIV +ve pts.*
*Resolves on withdraw of medication
What is the role of the nail organ?
Adds Stability to finger tip as counterforce to finger pulp
Thermoregulation- glomus bodies of nail/ nail bed
Extended Percision Grip- opposing thumb/index nails to remove a splinter
What is the nail plate made of and how much does it grow?
Where does it grow from
Made of keratin
Grows 3mm/ month, faster in summer
fingernails row faster than toes ( finger nails 3-6 months to regrow, toes 12-18 months)
Growth part is under eponychium
What are the symptoms of acute paronychia?
Pain
Nail fold tenderness
Erytherma
Swelling
What are the symptoms of chronic paronychia?
RECURRENT Boats of low grade inflammation
What do you find on examination of
1) acute paronychia and 2) chronic paronychia?
1) acute= Fluctuant
Nail plate discolouration- green= pseudomonas
2) Chronic ( see pic)- Nail plate hypertrophy- fungal infection
Nail fold blunting and retraction after rpt boats of inflammation
Prominent transverse ridges on nail plate
What are your differential diagnosis of a person with acute paronychia?
Herpetic whitlow
Felon
Onychomycosis
Psorasis
Glomus tumour
Mucous cyst
How do you tx acute paronychia?
Non operative- > Swelling but no fluctation= Warm soaks, oral antibiotics ( augmentin/clindamycin) and avoid nail biting
_Operative= fluctuation= _ Incision and drainage with partial or total nail bed removal
How do you tx chronic paronychia?
Non operative- warm soaks, avoid finger sucking, topical antifungals ( miconazole)- rarely antibiotics effective
Operative = Marsupialization ( See pic)= Excision of 3mm dorsal eponychrium crescent shape down to level of Germinal matrix ) combine with nail plate removal =Heal by secondary intention
Decribe your operative teachnique for incision and drainage of an acte paronychia with partial nail removal?
Approach
Incision into sulcus between lateral nail plate and lateral nail fold
Technique
preserve Eponychial fold by placing materials (removed nail) between skin and nail bed
If abscess extends proximally over eponychium (eponychia), a separate counterincision is needed over the eponychium
Obtain gram stain and culture
What are the complications of paronychia?
Eponychia- spreads to eponychium
Run around infection- both lateral folds involved
Felon- spreads to volar pulp- I& D required
Flexor tenosynovitis- volar spreads to felxor sheath
Subungual abscess- floating nail
What is this?
How does it occur?
A Felon
Infection of the volar pulp of the fingertip
Local spread from paronychia
Penetrating injury/ needle stick
Describe the anatomy of the pulp?
multiple small compartments of subcutaneous fat separated by fibrous septae between the distal phalanx and dermis
What is the pathology of a felon?
Swelling and pressure within micro-compartments, leading to “compartment syndromes” of the pulp
What are the causative organisms?
Staphylococcus aureus- most common
Gram negative organism- immunosupressed
Eikenella corrodens- in diabetics
What are the symptoms of a felon?
What are the signs ?
Pain and swelling of the finger pulp
Tenderness on palpation of the pulp
How do you tx a Felon?
Operative- incision and drainage
Due to risk of finger tip compartment syndrome
Can you describe the technique of incision and drainage of a Felon?
Approach:
Keep incision distal to DIP crease -T
o prevent DIP flexion crease contracture and prevent extension into flexor sheath.
Mid lateral approach - see picture below- Indicated for deep felons with no foreign body and not discharging.
Incision on ulnar side for digits 2,3 and 4 and radial side for thumb and digit 5 (non-pressure bearing side of digit)
Longitudinal approach ( see pic) most direct)
Indicated for superficial felons, foreign body penetration or visible drainage .
AVOID FISH MOUTH INCISIONS-> unstable fonger pulp
DOUBLE LONGITUDINAL or transverse incision - injury to digital nerve and artery
Can you describe the technique drainage of a Felon and what to avoid?
Avoid violating flexor sheath or DIP joint to avoid spread into these spaces
Aim to Break up septa to decompress infection and prevent compartment syndrome of fingertip
don’t forget gram stain and cultures
Leave wound open to allow drainage!
What are the complications of a felon?
Finger digitial tip necrosis
Finger tip compartment syndrome
Flexor tenosynovitis
Osteomyelitis
What types of bites are common? Which cause infection?
How does the patient present?
Dog and cat bites
Cat bites more frequently -needle like teeth -> deep penetration wound so high suspicion required
PC:Pain/swelling
Wound to arm/ hand
local or systemic sepsis
What are the common pathogens?
Pasterella Multicoida- 80% pt with cat bites
Staph aureus
Streptococcus alpha haemolytic
Bacteriodes
Corynebacterium
What is the pathology of dog and cat bites?
Dog bites-
Cause crush, puncture, avulsion, tears and abrasions
large dogs’ jaws exert >450lbs/ square inch
more likely to cause structural damage to nerves, vessels, joints
Cats have fine sharp teeth-> pentrating joints.
Puncture wounds that close immediately-> septic arthritis and osteomyelitis
What is the treatment of a cat/dog bite?
Thorugh cleaning of wound with saop or iodine - shown to dramatically reduce the devlopement of rabies in those bitten by infected animals
Non op Copious irrigation, appropriate antibiotics, tetanus and rabies prophylaxis
Antibiotics- amoxicillin/clavulanic acid effective against Pasteurella multocida,
ce furoxime or
ceftriaxone
Surgical debridment if crush/devitialised tissue, abscess, bites to pup space, flexor tendon, joinspace, deep space of hand, septic arthritis.
What is rabies?
Caused by a rhabdovirus
common animal carriers include dogs, raccoons, bats, foxes
Increased risk with open wounds, scratches/abrasions, mucous membranes
fatal bites associated with large aggressive dogs, small children, head and neck bites
prophylaxis is = human diploid cell vaccine and human rabies immunoglobulin
Immobilise limb and elevate
What is the incidence of human bites?
Males more affcted then females
Often occur around 3/4th MC after a fight- from direct punch another individual
Actual human bite
What is the pathology of a fight bite?
Tooth pentrated capsule of MCPJ
bacteria flora from mouth enter joint->infection
Bacteria get trapped in joint as it is flexed and caught unde extensor tendon
What organisms are common in human bites?
Alpha haemolytic strep *
Staph aureus*
Eikonella corrodens in 7-29%
*= most common
What other pathology is associated with fight bites?
Extensor tendon lacerations
What are the signs and symptoms of a fight bite?
What invetsigations would be orderd?
1) Pain, swelling to hand with puncture wound to 3/4 MC
Purulent discharge
Pain with passive and active rom
Test flexor and extensor tendons
2) xray hand to exclude any foreign bodies- teeth!
What is the TX for fight bites?
Operative- Incision and drainage
Debridement of wound
Open capsule
Leave wound open for drainage
Gram stain and culture
Iv antibotics for 48 hrs then change to oral for 5-7 days -target organism - amoxicillin/clavulanic acid (augmentin)
What is this ?
Pyogenic flexor tenosynovitis
Infection of the synovial sheath that surrounds the flexor tendon
What is the pathology of flexor sheath infections?
1) Penetrating injury
2) Spread from felon, deep space infection, septic arthritis
What are the organims involved in flexor sheath infections?
Staphylococcus aureus- most common
**Gram negative/ **Anaerobic bacteria= assoc HIV/ diabetic/ MRSA infections/ farmyard/ animal bites
What are flexor sheath infections commonly associated with?
Horseshoe abscess
Many individuals have a connection between the sheaths of the thumb and little fingers at the level of the wrist I
nfection in one finger can lead to direct infection of the sheath on the opposite side of the hand resulting in a condition known as a “horseshoe abscess’
Can you draw the flexor tendon sheaths?
Can you describe their role
See pic below
Tendon sheaths function to allow glide of tendons, provide nutrtion by bathe in synovial fluid and protect the flexor tendons
They extend DIPJ- midpalm in index, middle and ring fingers
From DIPJ to wrist ( ulna bursa) in little finger
from IPJ to wrist ( radial bursa) in thumb
What are the signs of a flexor sheath infection?
Kanavel signs - 4 signs in total
1) Flexed position of involved digit
2) Fusiform swellling of digit
3) Tenderness to palpation over tendon sheath
4) Marked Pain on passive stretch/extension
What are the normal sypmtoms of a flexor sheath infection?
Increase pain 48 hrs- localised to palmar aspect of digit
Swelling
Is imaging helpful in flexor tenosynovitis?
Xrays no use
MRI cannot distinguish infectious flexor tenosynovitis from inflammatory but may help determine the extent of the ongoing process
What is the treatment of flexor tenosynovitis?
Non op: in early intervention= Admit, elevation and iv antibiotics, close obeservation- surgery if no improvement in 24hrs
Surgery= incision and drainage of flexor sheath iv antibiotics following op to avoid ADHESIONS in flexor tendons
Describe the technique for closed drainage of flexor tenosynvoitis?
_Palmar incision: _
- transverse incision is made just proximal to distal palmar crease, over the infected tendon;
- spread thru the palmar aponeurosis;
- make incision just proximal to A1 pully and enter into sheath;
_Distal incision: _ - finger incision may be made either dorslateral at level of middle phalanx or directly on palmar surface at this level;
- incision can also be made in the distal flexor crease of digit;
- distal sheath is exposed thru ulnar midaxial incision & opened;
- enter sheath between annular pulleys, **insert small paeds feeding **catheter- (size no. 5 Fr) or 16 gauge catheter and irrigate +++
Iv antibiotics for 48 hrs then oral 2 weeks
Hand physio post to prvent adhesions
What is the treatment if need to open tendon sheath?
Brunner lines in finger to open skin then incise tendon sheath prox A1 pulley and annular pulleys distally
According to Hand Surgery Update 3 2003, Trumble states, open sheath irrigation has been replaced largely by closed sheath irrigation. These authors cite a retrospective study that showed no statistical difference in resolution of infection using open sheath irrigation or closed sheath irrigation, however, there was a trend towards more frequent complications and reoperations in the open drainage group.
What is this?
Where can these be located?
possibly a Deep space infection
Hypothenar, Thenar and Midpalmar space
other DD not in this picture
Collar button infection- ( abscess in webspace between fingers)
Can you describe the thenar, midpalmar and hypothenar spaces?
Thenar= A bursa (potential space) just palmar to adductor pollicis and dorsal to flexor tendons.
Separated from midpalmar potential space by a fascial septum
Midpalmar= dorsal and radial to hypothenar space
Hypothenar space= palmar to 5th MC, dorsal and radial to hypothenar fascia, ulnar to hypothenar septum
Which space is commonly infected in deep infections?
What are the signs and symtpoms?
Thenar
hx of penetrating injury to hand
Worsening swelling and pain
O/E pain on thumb flexion- thenar space finger
pain on little finger flexion- hypothenar
pain on flexion middle, ring index- midpalmar
What is the treatment of deep palmar infection?
Operative- incision and drainage
Technique
Use volar and dorsal incisions for collar button abscesses
Avoid skin in actual web space
Thenar space release-
dorsal incision (can spread to involve 1st dorsal interossei) or palmar incision
Midpalmar release- transverse incision across palm
webspace infection- incisions dorsal and volar to alow adequate drainage. Not transverse -> contractures
Who do Atypical mycobacterium infections affect?
What is the location of the infection?
Marine workers
Hand and wrist in 50% of cases
What is the pathophysiology of atypical mycobacterium?
Incubation period 2 weeks to 6 months
Average time to diagnosis and tx is 1 year
What are the types of organism causing atypical myocbacterium infections?
Mycobacterium marium*- injuries in marine environments/aquariums
mycobacterium avium-intracellulare*
*most common
M. kansasii - i soil
Describe the signs and symptoms of atypical mycobacterium infection?
How is it diagnosed?
Symptoms:cutaneous rash with discomfort
signs: papules, ulcers and nodules- indistinguishable to tuberculous mycobacterial infection
Dx by Culture requiring Lowenstein-Jensen culture agar at 30-32 degrees
How is atypical mycobacterium treated?
_NON OP _If diagnosed early with
ethambutol, tetraycline, trimethoprim-sulfamethoxazole, **clarithromycin, azithromycin **
add rifampin if osteomyelitis present
surgical debridement and antibiotics for later disease
What is this?
What is the incidence?
Fungal infection
serious in immunocompromised patients
Rare but common to have it in areas of macerated skin.
Fungal infectsions can be divided into 3 caterogeries, what are they?
Cutaneous - involving nail bed-Onychomycosis
Subcutaneous - sporothrix schenckii from rose thorn prick
Deep-orthopaedic manifestation= tenosynovial
septic arthritis,
osteomyelitis
What is this?
What causes it?
Onychomycosis
A Superficial fungal infection of the nail
Trichophyton rubrum=>a destructive nail plate infection
Candida=>chronic infection of nail fold
How is Onychomycosis treated?
Topical antifungals
Nail plate removal
systemic griseofulvin or ketoconazole if retractible disease
What is this infection?
What causes it ?
Sporothrix schenckii
A common soil bacteria
Rose thorn in classic mechanism of subcutaneous transmission
What are the signs of Sporothrix schenckii?
How is diagnosis confirmed?
A small papule where pentration of skin made then additional lesions in region of lymphatic tissue ( see pic)
S schenckii is isolated at room temperature on Sabouraud dextrose agar
How is Sporothrix schenckii treated ?
Oral itraconazole for 3 to 6 months
Can you name any fungi that cause deep infections?
Histoplasmosis-> sublclnical symptoms/ tenosynoval - found in rivers-tx amphotercin B, surgical debridment and tenosynovectomy
Coccidiomycosis- > arthritis/synovitis/ periarticular arthritis
**tx with amphocterin B and surgical debridement **
