USMLE: Step 1 First Aid
Rapid Review 2026.
Abdominal pain, ascites, Budd-Chiari Syndrome (post hepatic venous
hepatomegaly thrombosis). Associated with Polycythemia vera.
Achilles tendon Xanthoma Familial Hypercholesterolemia (absent/defective
LDL receptors)
May have MI before age 20
Autosomal dominant
Adrenal hemorrhage, hypotension, Waterhouse-Friedrichsen syndrome (Neisseria
DIC meningitidis)
Verified-testbank 1/20
, Anaphylaxis and/or angioedema IgA deficiency; C1 inhibitor deficiency would only
following blood transfusion cause angioedema, not anaphylaxis
Arachnodactyly (spider fingers), lens Marfan Syndrome (FBN1 gene mutation
dislocation, aortic dissection or chromosome 15 leads to defective fibrillin)
aneurysm, hyperflexible joints, Autosomal Dominant
pectus excavatum
Athlete with polycythemia Secondary to EPO injection
Back pain, fever, night sweats Pott disease (vertebral TB)
Bilateral acoustic schwannomas Neurofibromatosis type 2
S-100+, cerebellopontine angle
Bilateral hilar adenopathy, uveitis, Sarcoidosis (non-caseating granulomas)
high ACE, hypercalcemia (activated
macrophages for Vit D), interstitial
fibrosis, erythema nodosum,
elevated CD4:CD8 ratio on lavage;
asteroid bodies
Verified-testbank 2/20
, Black eschar on face of patient with Mucor or Rhizopus fungal infection
diabetic ketoacidosis Travels through cribiform plate vessels
Blue sclera Osteogenesis Imperfecta (Type I collagen defect
forming triple helix)
Blue due to exposure of choroidal veins
Bluish line on gingiva and basophilic Burton line (lead poisoning)
stippling Basophilic stippling (rRNA remnants)
Constipation, anemia, CNS impairment
Bone pain, bone enlargement (hat Paget disease of bone (Increased osteoclastic,
size or hearing loss), arthritis then osteoblastic activity)
Osteosarcoma or heart failure
Bounding pulses, wide pulse Aortic Regurgitation
pressure, diastolic heart murmur,
head bobbing
Verified-testbank 3/20
Rapid Review 2026.
Abdominal pain, ascites, Budd-Chiari Syndrome (post hepatic venous
hepatomegaly thrombosis). Associated with Polycythemia vera.
Achilles tendon Xanthoma Familial Hypercholesterolemia (absent/defective
LDL receptors)
May have MI before age 20
Autosomal dominant
Adrenal hemorrhage, hypotension, Waterhouse-Friedrichsen syndrome (Neisseria
DIC meningitidis)
Verified-testbank 1/20
, Anaphylaxis and/or angioedema IgA deficiency; C1 inhibitor deficiency would only
following blood transfusion cause angioedema, not anaphylaxis
Arachnodactyly (spider fingers), lens Marfan Syndrome (FBN1 gene mutation
dislocation, aortic dissection or chromosome 15 leads to defective fibrillin)
aneurysm, hyperflexible joints, Autosomal Dominant
pectus excavatum
Athlete with polycythemia Secondary to EPO injection
Back pain, fever, night sweats Pott disease (vertebral TB)
Bilateral acoustic schwannomas Neurofibromatosis type 2
S-100+, cerebellopontine angle
Bilateral hilar adenopathy, uveitis, Sarcoidosis (non-caseating granulomas)
high ACE, hypercalcemia (activated
macrophages for Vit D), interstitial
fibrosis, erythema nodosum,
elevated CD4:CD8 ratio on lavage;
asteroid bodies
Verified-testbank 2/20
, Black eschar on face of patient with Mucor or Rhizopus fungal infection
diabetic ketoacidosis Travels through cribiform plate vessels
Blue sclera Osteogenesis Imperfecta (Type I collagen defect
forming triple helix)
Blue due to exposure of choroidal veins
Bluish line on gingiva and basophilic Burton line (lead poisoning)
stippling Basophilic stippling (rRNA remnants)
Constipation, anemia, CNS impairment
Bone pain, bone enlargement (hat Paget disease of bone (Increased osteoclastic,
size or hearing loss), arthritis then osteoblastic activity)
Osteosarcoma or heart failure
Bounding pulses, wide pulse Aortic Regurgitation
pressure, diastolic heart murmur,
head bobbing
Verified-testbank 3/20
