Week 1
Name the 4 pathologies associated with HLA B-27
Psoriatic arthritis, reactive arthritis, entero-arthritis, ankylosing spondylitis
What are these lab findings showing?
UA would show Ig light chains (Bence Jones proteinuria) with negative urine dipstick
Serum: Sharp M-spike in the γ (gamma) region → monoclonal IgG or IgA, Normocytic anemia (low reticulocyte count), rouleaux formation oof RBCs on peripheral smear, Hypercalcemia,
Multiple myeloma
Why would a young patient present with their arm internally rotated, hand flexed, adducted
Bonus: what muscles are affected in this condition?
Erb's Palsy
Birds eat Erb’s; Biceps brachii, Infraspinatus, wRist extensors, Deltoid, Supraspinatus
What pathology is associated with IgG antibodies against desmoglein 3?
Phemigus Vulgaris
Name this pathology!
Erosions, juxta-articular osteopenia, soft tissue swelling, subchondral cysts, joint space narrowing (symmetric). Deformities: cervical subluxation, ulnar finger deviation, swan neck F , boutonniere G. Involves MCP, PIP, wrist; not DIP or 1st CMC.
Rheumatoid Arthritis
What are the 2 genetic mutations associated with osteosarcoma?
P53 and RB1
What are the 2 stages of aspirin toxicity?
Stage 1: respiratory alkalosis
Stage 2: metabolic acidosis (partially compensated respiratory alkalosis)
Salicylate toxicity can present with hyperthermia, altered mental status, and seizures (due to neuroglycopenia). Tachypnea, tinnitus, and acid-base abnormalities are also common.
What are the lab associations with lupus?
Screen: ANA (sensitive, but not specific).
Specific: anti-dsDNA (activity/nephritis), anti-Sm.
Antiphospholipid: anticardiolipin, lupus anticoagulant (↑PTT, arterial/venous clots, false-positive VDRL/RPR).
Low C3/C4, cytopenias; anti-histone = drug-induced lupus (I don’t like his tone when he’s on drugs)
Name the most logical organism that caused septic arthritis in (pick 3):
Most common
Sexually active young
Elderly/DM/urinary source
IVDU
Kids:
Most common: S. aureus
Sexually active young: N. gonorrhoeae.
Elderly/DM/urinary source: Gram-negatives (E. coli) + S. aureus.
IVDU: Pseudomonas, MRSA.
Kids: S. aureus, Strep; neonates add GBS.
Name this pathology!
Pleomorphic osteoid-producing cells (malignant osteoblasts). Presents as painful enlarging mass or pathologic fractures. Codman triangle (from elevation of periosteum) or sunburst pattern on x-ray, cloud-like osteoid; metaphysis
Osteosarcoma
Describe endochondral ossification
(Cartilage First; long bones, vertebrae, pelvis): Mesenchymal cells → chondroblasts → hyaline cartilage → blood vessel invasion (at diaphysis bring OB and OC) → osteoblasts (replace cartilage)
Name the common causes of avascular necrosis of the femoral head
Causes include glucoCorticoids, chronic Alcohol overuse, Sickle cell disease, Trauma, SLE, “the Bends” (caisson/decompression disease), LEggCalvé-Perthes disease (idiopathic), Gaucher disease, Slipped capital femoral epiphysis— CASTS Bend LEGS.
Name this pathology!
Systemic arthritis seen in < 16 years of age. Usually presents with daily spiking fevers, salmon-pink macular rash, arthritis (commonly 2+ joints). Associated with anterior uveitis. Frequently presents with leukocytosis, thrombocytosis, anemia, ^ ESR, ^ CRP.
Juvenile idiopathic arthritis
What are the ESR levels in fibromyalgia?
(Low, Normal, Elevated)
Normal!
Fibromyalgia is diagnosed clinically using the 2016 ACR criteria: chronic (>3 months), widespread pain (WPI ≥7 + SSS ≥5) with no other cause identified.
Causes of osteoporosis
Most commonly due to increased bone resorption (inc osteoclast number and activity) related to decreased estrogen/testosterone levels, old age, and cigarette smoking
Name this pathology!
Acanthosis with parakeratotic scaling (nuclei still in stratum corneum), Munro microabscesses. Increased stratum spinosum, decreased stratum granulosum. Auspitz sign
Psoriasis
Name this pathology!
congenital heart block, periorbital/diffuse rash, hepatitis (transaminitis), and cytopenias at birth
Neonatal lupus
What pathology presents with insidious onset of hip pain that may cause child to limp. More common in males (4:1 ratio). Initial x-ray often normal
Legg Calve Perthes
MOA of Alendronate
Induces osteoclast apoptosis; binds hydroxyapetitie in bone inhibiting osteoclast activity
Name this pathology!
Characterized by fever, bullae formation and necrosis, sloughing of skin at dermal-epidermal junction (⊕ Nikolsky), high mortality rate. Typically mucous membranes are involved
Stevens Johnson Syndrome