LOCO2 Flashcards
Define volkman contracture [1]
Volkmann contracture is a deformity of the hand, fingers, and wrist caused by injury to the muscles of the forearm.
The condition is also called Volkmann ischemic contracture.
How would a S. aureus infection appear in culture? [1]
Appears as grape like clusters, on trypticase soy agar plate produces yellow pigment: staphlyoxanthin
Common consequences of osetomeylitis? [2]
Rare consequences of osetomeylitis? [2]
Common:
* Local bone loss
* Persistent drainage through sinuses
Rare
* Squamous cell carcinoma
* Amyloidosis
Risk factors for osteomyelitis? [6]
Age
Malnutrition
Impairment of local vascular blood supply:
* Diabetes mellitus
* Venous stasis
* Radiation fibrosis (radiation therapy damaging blood vessels)
* Sickle cell disease (due to crisis)
Describe how you diagnose osteomyelitis [4]
How does it appear on ultrasound? [2]
(same as SA)
Local non-specific pain
Elevated neutrophil count (< 50% of cases)
Elevated ESR
Ultrasound:
* Cortical thinning
* Inflamation
* Periosteal lifiting: abscess lifting it off
How do you treat chronic osteomyelitis? [5]
Puncture drainage if abscessed
Surgical debridement
Reconstruct bone (allograft/ autograft)
Antibiotics (4-6wks, at least 2 IV):
* Vancomyocin cement beads
* Flucoxallin (gram +ve)
* Clindamycin
* Piperacillin
* Ciprofloxacilin
Describe the pathophysiology of scalded skin syndrome [2]
Exotoxins are proteases that destroy desmosomes holding keratinocytes in granulosum and spinosum layers together:
Causes widespread fluid filled blisters that easily break
Therapy for Necrotising fascitis? [3]
Treatment:
* Surgical debridement
* Empiric antibiotics
* Hyperbaric oxygen (Add on therapy)
Treatment for HPV: viral warts and veruccas? [5]
Topical salicylic acid
**Fluorouracil cream **
Cryosurgery
Surgical curettage
Laser treatment (CO2 laser 582nm)
Describe what Postherpetic neuralgia (PHN) is [2]
Unpredictable complication of varicella zoster virus- (VZV-) induced herpes zoster (HZ) which often occurs in elderly and immunocompromised persons
The main symptom of post-herpetic neuralgia is intermittent or continuous nerve pain in an area of your skin previously affected by shingles.
Treatment for leprosy? [3]
Rifampicin, dapsone and clofazimine
State what the acetabular angle should be for each of the following ages?
0 - 1 year old < []
1 > 4 year old < []
> 4 year old < []
The acetabular angle should decrease with age:
0 - 1 year old < 34
1 > 4 year old < 28
> 4 year old < 25
Explain the pathophysiology of heterotopic bone [3]
Fibroblasts, osteoblasts and chondroblasts come from same precursors
Tendon fibroblast differentiate into chondrocytes / hypertrophic chondrocyte and osteoblasts via COX-2
Pro-inflammtory cytokines like prostaglandin E2 induces osteoblasts to differentiate
Describe enthesitis pathogenesis:
Normal enthesitis insertion occurs at a location with lots of which structure? [1]
How does this influence enthesitis pathogenesis? [3]
Normal enthesis inserts into porous bone at a location with lots of small transcortical vessels (TCV)
Mechanical trauma; TCVs become inflammed:
* Vasodilation
* Efflux of immune cells (neutrophils)
* Osteoblasts form bone at enthesis - causes bone to be formed
Enthesitis is associated with which three conditions? [3]
Ankylosing spondylitis
Psoriatic arthritis
IBD
How do you treat enthesitis:
- If mechanical? [2]
- If Inflammatory [5]
Mechanical:
* RICE
* NDSAIDs
Inflammatory:
* Sulfasalazine
* Methotrexate
* Anti-TNF therapy (restricted use for severe autoimmune enthetitis)
* Local radiotherapy
* Corticosteroid injection
* Hyperosmolar dextrose (initiates proliferation of intrinsic fibroblasts - race to repair damage c.f. osteoblasts)
DMARD treatments for SLE? [4]
Cylcophosphamide
Mycophenolate mofetil
Methotrexate
Tacrolimus
Describe two biological DMARDs for SLE? [2]
Belimubab: inhibits BAFF (B cell activating factor)
Rituximab: CD20 blocker
How can you treat resistant urticaria and asthma?
Omalizumab: binds free IgE in the serum, forming trimers and hexamers
Treatment of Pemphigus Vulgaris? [3]
Oral steroids
Immunosuppresion: mycophenolate mofetil or azathioprine
Rituximab (targeting CD20 on B cells)
Describe the features of Immune Complex Mediated Vasculitis [4]
Antigen and antibody form an immune complex
This causes production of proteins and aggregation of platelets into micro thrombi
This results in:
* Deposition of fibrin
* Leaky vessel and extravasation of blood and oedema.
* The proteases degrade vessel BMZ
* Necrosis of the vessel wall
Allergic Contact Dermatitis pathogenesis? [3]
Promotion of Th1 response:
- Secretion of IL2, IL3, GM-CSF, IFNg and TNF
- This promotes a macrophage rich response
- Causes inflammation to the skin around 48 hours to 72 hours after the challenge
New drug class treatments for AA and Vitiligo? [1]
Name an example drug [1]
JAK Inhibitors
E.g Ruxolitinib
Pemphigus Vulgaris occurs due to autoantibodies directed at a cadherin-type epithelial cell adhesion molecule called what? [1]§
Desmoglein 3
