Differential Diagnoses Game!

Question 1

DDx for Headache

Answer 1

Tension type headache
Migraine with/without aura
Medication overuse headache
Meningitis/Encephalitis
Space occupying lesion

Idiopathic Intracranial Hypertension
Cervicogenic
Cluster headache (uncommon - Males 20-40yrs)
Giant Cell Arteritis
Medication Side Effect: eg. calcium channel blocker

Subarachnoid haemorrhage
Trigeminal neuralgia
Haemorrhagic stroke
Venous Sinus Thrombosis
Malignant Hypertension
Acute glaucoma

Question 2

Name Organic Causes of Psychosis

Answer 2

Brain space occupying lesion
Encephalitis
Neurosyphilis
Substance abuse/intoxication/withdrawal
Temporal Lobe epilepsy
Hypoglycaemia/hyperglycaemia
Hypothyroidism/Myxoedema, Thyrotoxicosis
CNS infection: Encephalitis/Meningitis
Space occupying lesion
Electrolyte abnormality
Metabolic abnormality
Sleep deprivation
HyperPTH
Cushing disease
Cerebrovascular disease
HIV infection
Neurosyphilis
Vitamin B deficiency
Creutzfeldt Jakob Disease
Heavy Metal Toxicity
Wilson Disease
SLE

Question 3

Mental Health related Causes of Psychosis

Answer 3

Schizophreniform disorder (if <6mo)
Schizophrenia (if >6m)
Manic episode of bipolar affective disorder
Brief psychotic episode/disorder
Depression with psychotic features
Delusional disorder
Alcohol/Substance induced psychosis

Question 4

DDx Syncope

Answer 4

Vasovagal
Situational (eg. micturition, coughing, post prandial)
Orthostatic
Tachy/brady arrhythmia or Long QT syndrome
Seizure
Psychogenic pseudoseizure
Alcohol intoxication
Subarachnoid haemorrhage
Carotid sinus massage
Aortic stenosis/HOCM

Question 5

DDx Acute Red Eye

Answer 5

Conjunctivitis - bacterial, viral, allergic
Blepharitis
Foreign body
Corneal abrasion
Contact hypersensitivity
Subjunctival haemorrhage
Orbital cellulitis
HSV keratitis (painful)
Corneal ulcer (painful)
Scleritis/episcleritis
Acute uveitis/iritis
Acute glaucoma (fixed dilated pupil, blurry vision)

Question 6

DDx Acute Visual Loss

Answer 6

Retinal detachment (flashing lights)
Optic Neuritis (painful)
Retinal Artery Occlusion (CV risk factors)
Retinal vein occlusion (CV risk factors)
Posterior vitreous detachment
Vitreous haemorrhage
Acute angle glaucoma (painful and blurring, fixed semi-dilated pupil)

Non-Orbital:
Amaurosis Fugax secondary to CVA
Giant cell arteritis
Migraine with or without headache
Papilloedmea (idiopathic intracranial hypertension)

Question 7

Specific causes of mechanical back pain

Answer 7

Muscular tear or strain
Mechanical back pain
Pathological Fracture
Disc prolapse
Facet joint pain
Osteoporotic fracture

Question 8

DDx Peripheral Neuropathy

Answer 8

Diabetes
Vitamin B12 deficiency
Vitamin B1 deficiency (usu. ETOH use or Bariatric Surgery)
Neurotoxic drugs (eg amiodarone, nitrofurantoin)
Immunological eg. Guillain-Barré syndrome
Vasculitis
Sarcoidosis
Leprosy
Heavy metal poisoning
Porphyria

Localised:
Nerve root compression/disease
Physical trauma
Compartment syndrome
Carpal/Tarsal tunnel syndrome

Asychronous pattern:
Mononeuritis multiplex

Mixed UMN/LMN: MS or ALS

Question 9

DDx Shoulder Pain

Answer 9

Fracture/dislocation
Rotator cuff tear (Usu. Supraspinatus)
Labral tear
Gleno-humeral subluxation
Biceps tendinopathy

Tendinopathy/calcific tendonitis
Bursitis
Impingement
Degenerative tears
Adhesive capsulitis/frozen shoulder
Septic arthritis

Cervical pathology
OA
Rheumatological (PMR, RA)
Malignancy (rare)
Extrinsic (esp if normal ROM): PE, AMI, hepatobiliary

Question 10

DDx Tremor

Answer 10

Physiological (50% autosomal dominant)
Benign essential (familial) - most common
Anxiety (
Hyperthyroidism
Toxicity (eg. alcohol, liver failure, uraemia)
Drugs (eg. lithium, narcotic withdrawal, drug-induced parkinsonism)
Parkinson’s Disease
Cerebellar Disease
Cerebral tumour
Alzheimer Dementia
Wilson Syndrome

Other: hypoglycaemia
Other involuntary movements: myoclonus, tic, chorea, dystonia, fasciculations

Question 11

DDx Urinary Symptoms - general

Answer 11

General:
UTI (acute/chronic)
Urethral stricture
STI
Bladder calculi
Interstitial cystitis
OAB
Neurological condition
Diabetes
Iatrogenic
Constipation

Question 12

DDx Lower Urinary Symptoms - male

Answer 12

General:
UTI (acute/chronic)
Urethral stricture
STI
Bladder calculi
Interstitial cystitis
OAB
Neurological condition
Diabetes
Iatrogenic
Constipation

Male:
BPH
Prostate or Bladder Ca
Phimosis
Prostatitis (acute/chronic)

Female:
Vaginal prolapse
Vaginal atrophy

Question 13

DDx Vertigo

Answer 13

BPPV
Vestibular neuritis
Meniere’s Disease
Labyrinthitis
CVA, Vertebrobasilar insufficiency
MS
Space occupying lesion/tumour
Cholesteatoma
Acoustic neuroma/vestibular schwannoma
Ramsay-Hunt syndrome
Psychogenic
Perilymphatic fistula

Non-Vertiginous: syncope, light-headedness
Frusemide induced ototoxicity

Question 14

DDx Child with a Limp

Answer 14

Transient Synovitis
Septic arthritis
Fracture/MSK
NAI
Malignancy
Vasculitis: HSP
Referred pain

DDH
Toddler’s Fracture

Perthes Disease

SUFE
JIA
Osgood Schlatter Disease

Question 15

DDx Heel Pain

Answer 15

Plantar Fasciitis
Calcaneal Fat Pat Atrophy
Achilles Tendinopathy
Retrocalcaneal Bursitis
Calcaneal stress fracture
Calcaneal apophyisis (usu. Children)

Question 16

DDx Fever in a Returned Traveller

Answer 16

Fever Alone:
Malaria
Typhoid
Dengue Fever
Hepatitis A
Chikungunya
Rickettsial infection

Fever + Diarrhoea
As above PLUS
Traveller’s Diarrhoea
Cholera
Dysentry

Fever + Respiratory
Malaria
Pnuemonia (typical or atypical)
Influenza
Pulmonary tuberculosis
Viral respiratory (eg. Rhinovirus)

Fever + STI risks
Hepatitis
Syphilis
HIV
Gonorrhoea/Chlamydia

Non-Vaccinated
Measles
Rubella

Onset >2 weeks after travel
Malaria
EBV
CMV
Toxoplasmosis
Acute HIV
Acute Shistosomiasis
Brucellosis
TB
Q fever
Malaria
Acute Hepatitis

Question 17

DDx Uncontrolled Hypertension

Answer 17

Phaeochromocytoma
Conn’s Disease
OSA
Renal Artery Stenosis
Renal disease (eg. nephritis)
Hyperthyroidism
Cushings
Cardiomyopathy
Drug side effect (steroids, NSAIDs)
Non-compliance with medications
White coat syndrome
Alcohol/Elicit substance use

Question 18

DDx Acute Cough

Answer 18

Bronchiolitis
Croup
Tonsillitis/pharyngitis
Post viral cough
Inhaled foreign body
Whooping cough
Asthma

Rhinitis/sinusitis (allergic vs. non allergic)
Occupational asthma
Atypical pneumonia
TB
Psychogenic

Heart Failure

Question 19

DDx Elevated Lipids

Answer 19

Primary hyperlipidaemia

Familial hypercholesterolaemia
Metabolic syndrome
Hypothyroidism
Nephrotic syndrome/CKD
T2DM
Cholestasis/obstructive liver disease

Drugs: thiazide diuretics, beta blockers, oral oestrogens, atypical antipsychotics, antiretroviral drugs for HIV

Question 20

DDx Epigastric Pain

Answer 20

Gastrooesophageal Reflux Disease
Peptic Ulcer Disease
Hiatus hernia
Eosinophilic oesophagitis
MSK (costochondritis)
Gastroenteritis

Pericarditis
Aortic Dissection
PE
AMI/Angina

GI: hepatitis, pancreatitis, cholecystitis

Question 21

DDx Pelvic Pain

Answer 21

Ectopic Pregnancy
PID
STI: chlamydia, gonorrhoea
Large fibroids
Uterine adhesions
Ovarian torsion/cyst rupture

Urinary retention
Cystitis
Renal Stones
Incarcerated hernias
Lymphadenopathy
Malignant mass

Appendicitis
Crohn Disease

Question 22

DDx Fatigue/Tiredness

Answer 22

Depression/Stress/Generalised Anxiety
Diabetes
Sleep deprivation
Iron deficiency anaemia
Hypothyroidism
Fibromyalgia
Chronic Fatigue Syndrome
Coeliac Disease
Cancer

Vitamin B12 deficiency
Pregnancy
Substance abuse

Question 23

DDx Back Pain

Answer 23

Muscular
Osteomyelitis/epidural abscess
Metastatic Disease
Acute spinal fracture
Osteoporosis
Atypical AMI presentation
GORD
Ankylosing spondylitis (other rheum arthritis)

“Muscular”
- Spondylolisthesis
- Muscular tear or strain
- Mechanical back pain
- Pathological Fracture
- Disc prolapse
- Facet joint pain
- Osteoporotic fracture

Question 24

DDx RUQ Abdominal Pain

Answer 24

Cholecystitis
Choledocolithiasis
Ascending Cholangitis
Cholangiocarcinoma

Hepatitis (eg. infectious)
Primary Biliary Sclerosis
Primary Sclerosing Cholangitis

Pancreatitis

Peptic Ulcer Disease
GORD

Less Likely: Cardiac, MSK, Oesophageal, Renal Colic

Question 25

DDx Testicular Swelling

Answer 25

Hydrocele
Varicocele
Epididymo-orchitis
Inguinal Hernia
Testicular Torsion
Testicular Cancer
Idiopathic scrotal oedema
Post-traumatic

Question 26

DDx Amenorrhoea

Answer 26

Hypothalamic dysfunction (high exercise, eating disorder, low BMI, stress, medical illness)

Primary
- Constitutional delay of puberty
- Congenital absence of uterus or vagina
- Imperforate hymen
- Chromosomal abnormalities (Eg. Kallman , Turner)

Secondary
Pregnancy/ectopic
Hypothyroidism
Hyperprolactinaemia
PCOS
Uterine Adhesions
CAH
Cushings
Menopause
Primary ovarian insufficiency

Question 27

DDx Floppy Baby (Hypotonia)

Answer 27

Down Syndrome
Prader-Willi Syndrome
Trisomy 13
Trisomy 18

Muscular Dystrophy

Hypotonic cerebral palsy

Congenital hypothyroidism
Hypoglycaemia

Inborn errors of metabolism

Question 28

DDx Palpitations

Answer 28

Premature ectopic beats
Atrial fibrillation
Paroxysmal SVTs
WPW or Brugada Syndrome

Phaeochromocytoma
Hyperthyroidism
Anaemia
Electrolyte disorder
Sepsis

Anxiety/Stress
Drugs: caffeine, amphetamines

Question 29

DDx Wrist Pain

Answer 29

De Quervain’s Tenosynovitis
Carpal Tunnel Syndrome

Arthropathy (Osteo/RA/gout/psoriatic)

Scaphoid Fracture
Distal radial/ulnar fracture

Question 30

DDx Nausea/Vomiting

Answer 30

CNS - head injury, CVA, mass lesion, migraine, seizure disorder, vestibular

GI - Functional disorders, obstruction, appendicitis/pancreatitis/etc

Infectious - gastroenteritis, UTI, pneumonia, viral

Medication/Toxin - antibiotics, chemotherapies, alcohol overdose, opiates, arsenic

Metabolic - DKA, paraneoplastic syndrome, pregnancy, uraemia

Other - Pain, psych, AMI, acute glacoma,

Question 31

DDx Knee Pain

Answer 31

Osteoarthritis
Reactive, psoriatic, gouty arthritis,
Traumatic: fracture, ligamental, meniscal
Bursitis
Septic Arthritis
Patellofemoral syndrome, Iliotibial Band Syndrome
Malignancy

Question 32

DDx Hip Pain

Answer 32

OA
Greater trochanteric pain syndrome
Septic arthritis
NOF fracture
Referred lumbar back pain
Iliopsoas bursitis
Merlagia Paraesthetica
Femoroacetabular impingement

Question 33

DDx Ankle Pain

Answer 33

Posterior: Achilles tendonopathy, Superficial calcaneal bursa

Medial: Tibialis posterior or flexor hallucis longus tendinopathy

Anterior: Tibialis anterior tendinopathy

Ankle sprain (Anterior talofibular ligament is the most often sprained)

Arthropathies: gout, reactive, osteoarthritis, septic arthritis
Claudication
Peripheral oedema

Question 34

DDx Shortness of Breath

Answer 34

Acute viral illness
Pneumonia
Pulmonary Oedema
Interstitial Lung Disease
Asthma/COPD
Lung malignancy

Ischaemic Heart Disease
Pulmonary Embolism
Congestive Cardiac Failure
Pneumothorax

Hyperthyroidism
Anaemia
Acidosis (eg. DKA)
Obesity
Anxiety/Panic

Question 35

DDx Early Pregnancy Bleeding

Answer 35

Ectopic Pregnancy
Non-viable pregnancy
Threatened Miscarriage
Molar pregnancy

Implantation bleeding

Cervical: trauma, ectopion, polyp, malignancy, infection

Question 36

DDx Antepartum Haemorrhage

Answer 36

Placenta praevia
Vasa praevia
Placental abruption

Show
Cervical: trauma, cervicitis, polyp, ectropion, carcinoma, insufficiency

Question 37

DDx abdominal pain - paediatrics

Answer 37

Sudden onset: testicular/ovarian torsion, intussusception, volulvus, perforated viscus, incarcerated hernia

Bloody diarrhoea: gastroenteritis, Meckel’s diverticulum, IBD

Bilious vomiting: volvulus, obstruction

Polyuria/polydipsia/weight loss: DKA

Episodic/colicky: constipation, gastroenteritis, intussusception, mesenteric adenitis, ovarian torsion

Increasing severity + localisation: appendicitis

Vomiting/diarrhoea: gastroenteritis

Cough/fever: pneumonia

Dysuria/frequency/fever: UTI, pyelonephritis