MSK - Level 3 Flashcards
Description of seronegative arthritis?
- Group of conditions that present with inflammatory arthritis without a positive RF
- Include Ankylosing spondylitis, Reiter’s syndrome, psoriatic arthritis, Behcet’s disease, JIA
Risk factors of seronegative arthritis?
o HLAB27
o FHx
Mean onset and symptoms of seronegative arthritis?
- Mean onset 20-40 o Back pain o Sacroilitis o Peripheral arthritis o Enthesitis o Dactylitis o Non-gonococcal urethritis o Psoriasis o Anterior Uveitis o IBD
What is psoriatic arthritis?
o 35-45, any joints
o Psoriasis, enthesitis, dactylitis
o Occasional uveitis, aortic regurgitation
What is enteropathic arthritis?
o Any age
o Asymmetrical lower extremities and symmetrical sacriliitis
o Erythema nodosum, pyoderma gangrenosum
o Aortic regurgitation
Investigations in seronegative arthritis?
- Bloods
o ESR and CRP raised
o Urate, RF, ANA normal - X-ray
Management of seronegative arthritis?
- Treat the type of spondylopathy
- Exercise, physiotherapy
- NSAIDs
- DMARDs
- Surgery – joint replacements
Physiology of vitamin D?
- Vitamin D is fat soluable vitamin that regulates calcium and phosphate homeostasis
- Promotes absorption of calcium and phosphorus from bowel to mineralise newly formed osteoid bone tissue
Forms of vitamin D?
o Vitamin D3 (cholecalciferol) – synthesised from 7-dehydrocholesterol in skin by UVB radiation (sunlight)
o Both D3 and D2 (ergocalciferol) are obtained from foods
Cod liver oil, oily fish and fortified cereals/spreads
o D2 and D3 are inactive – converted to 25-hydroxyvitamin D in liver and then to 1, 25(OH)2D in kidneys
Regulation of vitamin D?
o Production regulated by PTH on kidneys
Definition of osteomalacia and Ricket’s?
- Osteomalacia – normal bone amount but mineral content low, occurs after fusion of epiphysis
- Rickets = if this process occurs during period of growth
Causes of osteomalacia?
o Insufficient sunlight exposure
Depends on latitude, season and habit of dressing
Age
Darker skin need more sunlight
o Inadequate dietary intake
o Intestinal malabsorption – coeliac, CF, Crohn’s
o Obesity
o Liver failure
o CKD
o Drugs – antiepileptics, corticosteroids, rifampicin, HAART
Risk factors of osteomalacia?
o Muslim women o Housebound patients o Dark skin (African, Afro-Caribbean, Asian) o Vegans o Pregnancy o >65 o Obese o FHx
Symptoms of Ricket’s?
o Growth retardation
o Hypotonia
o Apathy
o Once walking: knock knee, bow legs, rachitic rosary
o Painful wrist swelling
o Craniotabes (skull softening with frontal bossing
o Delayed tooth eruption
Symptoms of osteomalacia?
o Bone pain – lower back, pelvis
o Fractures (esp femoral neck)
o Muscles aches
o Proximal myopathy (waddling gait)
Investigations in child with suspected Ricket’s?
o XR of long bone – cupping, splaying, fraying of metaphysis (champagne glass wrist) o Bone profile Vitamin D if low calcium o U&E o LFT o TFT o PTH o FBC, ferritin o RA o CRP/ESR
Investigations must be done in osteomalacia?
o Test serum 25(OH)D levels if present with symptoms
Diagnosis if <25nmol/L
25-50 may be inadequate for some people
Investigations considered if underlying cause suspected in osteomalacia?
Bone profile U&E LFT TFT PTH FBC, ferritin RA CRP/ESR
Prevention management of osteomalacia?
o Take daily 400IU (10mcg) supplement daily throughout year
If pregnant – can get free Healthy Start vitamins (has vitamin D, 400mcg folic acid and 70mg VitC)
If <1 years old – 340-400IU of vitamin D
o Advise to intake 700mg of calcium a day
If unable – combined calcium supplementation (Calcichew D3)
• Check Ca levels 1 months after
If child, recommended levels are different
o Lifestyle advice
Sun exposure – safely
Diet – supplements, cod liver oil, oily fish, egg yolk, meat
Management of osteomalacia - who to treat?
Serum 25(OH)D <25
Serum 25(OH)D 25-50 if:
• Fragility fracture, osteoporosis, on antiresorptive drug treatment, symptoms, raised PTH, CKD, coeliac, Crohn’s
Management of osteomalacia - how to treat?
Refer if cancer, Crohn’s to specialist
Drug treatment
Vitamin D2 – for strict vegans (from plant sources)
Vitamin D3 (cholecalciferol) for everyone else
• Loading dose of 300000 IU (50,000 IU once a week for 6 weeks) then daily 800IU maintenance
Management of osteomalacia - follow up?
1 month of high-dose Vitamin D treatment
• Serum calcium levels
3-6 months of high-dose Vitamin D treatment
• Serum 25(OH)D levels:
o IF <50 – refer to secondary care
o IF >50 and no symptoms of hypercalcaemia – maintenance dose of 800IU daily
Management of child with Ricket’s?
o Refer is underlying cause
o Refer to paediatrician if symptoms of Ricket’s
o Drug Treatment
Age 1-6 months – 3,000 IU daily for 8-12 weeks
Age 6 months-12 years – 6,000IU daily for 8-12 weeks
Age 12-18 years – 10,000IU daily for 8-12 weeks
Prognosis of osteomalacia?
o Correct management – restores levels and reduces risks