​Symptoms and Signs – Differential Diagnosis of Tardive Dyskinesia
• Brain neoplasms
• Extrapyramidal syndrome (postanoxic or postencephalitic)
• Huntington’s disease
• Idiopathic dystonias (tics, blepharospasm, aging)
• Ill-fitting dentures
• Medications (antidepressants, anticholinergics, amphetamines, lithium, levodopa, phenytoin)
• Torsion dystonia
• Wilson’s disease

​Symptoms and Signs – Differential Diagnosis of Tall Stature
CONSTITUTIONAL (FAMILIAL OR GENETIC)
Most common cause
ENDOCRINE CAUSES
• Growth hormone excess: gigantism
• Sexual precocity (tall as children, short as adults): true sexual
precocity, pseudosexual precocity
• Androgen deficiency: Klinefelter’s syndrome, bilateral anorchism
GENETIC CAUSES
• Klinefelter’s syndrome
• Syndromes of XYY, XXYY
MISCELLANEOUS SYNDROMES AND DISORDERS
• Cerebral gigantism or Sotos syndrome: prominent forehead, hypertelorism, high arched palate, dolichocephaly, mental retardation, large hands and feet, and premature eruption of teeth; large at birth, with most rapid growth in first 4 years of life
• Marfan syndrome: disorder of mesodermal tissues, subluxation of the lenses, arachnodactyly, aortic aneurysm
• Homocystinuria: same phenotype as Marfan syndrome
• Obesity: tall as infants, children, and adolescents
• Total lipodystrophy: large hands and feet, generalized loss of subcutaneous fat, insulin-resistant diabetes mellitus, hepatomegaly
• Beckwith-Wiedemann syndrome: neonatal tallness, omphalocele, macroglossia, neonatal hypoglycemia
• Weaver-Smith syndrome: excessive intrauterine growth, mental
retardation, megalocephaly, widened bifrontal diameter, hypertelorism, large ears, micrognathia, camptodactyly, broad thumbs, limited extension of elbows and knees
• Marshall-Smith syndrome: excessive intrauterine growth, mental retardation, blue sclerae, failure to thrive, early death

​Symptoms and Signs – Differential Diagnosis of Takayasu’s Arteritis
• Behçet’s disease
• Buerger’s disease
• Cogan’s syndrome
• Giant cell arteritis
• Kawasaki’s disease
• Rheumatoid arthritis (RA)
• Spondyloarthropathy
• Syphilis
• Systemic lupus erythematosus (SLE)
• TB

​Symptoms and Signs – Differential Diagnosis of Systemic Lupus Erythematosus
• Infection
• Metastatic neoplasm
• Other connective tissue disorders (e.g., rheumatoid arthritis [RA], mixed connective tissue disease [MCTD], progressive systemic sclerosis)

​Symptoms and Signs – Differential Diagnosis of Syringomyelia
• Tabes dorsalis
• Spinal cord tumor
• Progressive spinal muscular atrophy
• Multiple sclerosis (MS)
• Amyotrophic lateral sclerosis (ALS)

​Symptoms and Signs – Differential Diagnosis of Sudden Death, Young Athlete
• Aortic valve stenosis
• Arrhythmias
• Asthma
• Atherosclerotic coronary artery disease
• Cardiac sarcoidosis
• Coronary artery anomalies
• Dilated cardiomyopathy
• Drug and alcohol abuse
• Heat stroke
• Hypertrophic cardiomyopathy
• Myocarditis
• Ruptured aortic aneurysm (Marfan syndrome)
• Trauma (cerebral, cardiac)

​Symptoms and Signs – Differential Diagnosis of Syncope
• Psychological stress
• Recreational drugs/alcohol
• Seizure
• Vertebrobasilar transient ischemic attack (TIA) (usually manifested as diplopia, vertigo, ataxia but not loss of consciousness)

​Symptoms and Signs – Differential Diagnosis of Syndrome of Inappropriate Antidiuresis
• Factitious hyponatremia (hyperglycemia, abnormal proteins, hyperlipidemia)
• Hyponatremia associated with hypervolemia (congestive heart failure, cirrhosis, nephrotic  syndrome)
• Hyponatremia associated with hypovolemia (e.g., burns, GI fluid loss)

Symptoms and Signs – Differential Diagnosis of Stridor, Pediatric Age
RECURRENT
• Allergic (spasmodic) croup
• Respiratory infections in a child with otherwise asymptomatic
anatomic narrowing of the large airways
• Laryngomalacia
PERSISTENT
• Laryngeal obstruction
• Laryngomalacia
• Papillomas, other tumors
• Cysts and laryngoceles
• Laryngeal webs
• Bilateral abductor paralysis of the cords
• Foreign body
• Tracheobronchial disease
• Tracheomalacia
• Subglottic tracheal webs
• Endotracheal, endobronchial tumors
• Subglottic tracheal stenosis
• Congenital
• Acquired
• Extrinsic masses
• Mediastinal masses
• Vascular ring
• Lobar emphysema
• Bronchogenic cysts
• Thyroid enlargement
• Esophageal foreign body
• Tracheoesophageal fistulas
OTHER
• Gastroesophageal reflux
• Macroglossia, Pierre Robin syndrome
• Cri du chat syndrome
• Hysterical stridor
• Hypocalcemia

​Symptoms and Signs – Differential Diagnosis of Stomatitis, Dark Lesions (Brown, Blue, Black)
• Coated tongue: accumulation of keratin; harmless condition that can be treated by scraping
• Melanotic lesions: freckles, lentigines, lentigo, melanoma, Peutz- Jeghers syndrome, Addison’s disease
• Varices
• Kaposi’s sarcoma: red or purple macules that enlarge to form tumors; seen in patients with AIDS