Pathology

Question 1

Rash, uticaria, fever, polyarthralgia, polyarthritis, lymphadenopathy,
Begins 1-2 weeks after drug exposure
Type III HSR
Self Limited

Dx? Path? Tx?

Answer 1

Dx: Serum Sickness

Path: Drugs acts like a hapten - binds serum/cell membrane proteins (complex formation) and activates immune system

Tx:
Discontinue offending agent
Prednisone + Diphenhydramine

Question 2

Hearing loss, tenderness over bones, skull enlargement, chalk-stick fractures, high output heart failure

X-ray: increased bone density, cortical thickening, bowing, bone overgrowth, lytic bone lesions

Dx? Path? Labs? Associated cancer? Tx?

Answer 2

Dx: Osteitis deformans (Paget disease)

Path: ⬆️ osteoclast activity followed by ⬆️ osteoblast activity and the formation of poor quality bones

Labs: Normal serum calcium, phosphorus, vitamin D, and PTH. ⬆️ Alkaline phosphatase

Associated with osteosarcoma

Tx: Bisphoshonates

Question 3

Red skin, lactic acidosis (High anion gap metabolic acidosis), HTN, tachycardia, tachypnea, headache, confusion, seizure

Dx? Path? Tx? MOA?

Answer 3

Dx: Cyanide poisoning
Path: Cyanide inhibits cytochrome c oxidase in ETC –> inhibition of oxidative phosphorylation –> inhibition of aerobic metabolism

Tx:

• 100% O2
• Hydroxocobalamin (indicated for cyanide + CO poisoning, such as from house fires)
• Sodium nitrate (contraindicated in concomitant CO poisoning)

MOA:
1. Hydroxocobalamin: binds intracellular cyanide to form cyanocobalamin, which is excreted in urine

2. Sodium nitrate: induces formation of methemoglobin –> mops up cyanide in blood to form cyanomethemoglobin

Question 4

Mucocustaneous bleeding in children
Abnormal ristocetin test
Large platelets
Autosomal recessive
Absent or decreased GP Ib expression

Dx?

Answer 4

Bernard Soulier Syndrome

Question 5

Mucocutaneous bleeding in children
Failure of platelet clumping
Decreased expression of GP IIb/IIIa
Autosomal recessive

Dx?

Answer 5

Glanzmann Thrombasthenia

Question 6

IgG antibodies against platelets