This document outlines Murtagh's diagnostic strategy for primary care physicians. It involves considering: 1) The probability diagnosis based on presenting symptoms, 2) Serious disorders that cannot be missed, 3) Conditions that are often overlooked or misdiagnosed, 4) Whether the patient's symptoms could represent a masquerade of another condition, and 5) If the patient may be indicating something else through their symptoms. It then provides an example of applying this strategy to a 15-year-old girl presenting with headaches.

1. WHY? Know the specific pathophysiology Know the natural history (prognosticate) Inform patient of the diagnosis Appropriate investigation Treatment Communication within medical profession DIAGNOSTIC PROCESS IN PRIMARY CARE

2. ‘ Disease-centered diagnosis’ ‘ Patient-centered diagnosis’ – includes the patient’s thoughts and feelings concerning their complaints

3. WHAT IF WE CANNOT MAKE A DIAGNOSIS? sometimes impossible to make a diagnosis ‘ diagnosis’ then can be expressed in the form of the patient’s problems Nature of Primary Care Front line of medicine Undifferentiated symptoms Varying degrees of severity Using time as a waiting tool

4. INDUCTIVE METHOD OF PROBLEM-SOLVING Need to take a comprehensive history System review Complete physical examination Investigations Diagnosis may not be used by all practitioners time- consuming unfocused

5. MURTAGH’S DIAGNOSTIC STRATEGY What is the probability diagnosis? What serious disorders must not be missed? What conditions are often missed (the pitfalls)? Could this patient have one of the ‘masquerades’ in medical practice? Is this patient trying to tell me something else?

6. Apply Murtagh’s strategy Probability Serious disorders Pitfalls Masquerades Hidden agenda Linda 15-year-old girl Headaches for the past 2 weeks

7. Serious ‘not to be missed’ conditions Neoplasia, especially malignancy HIV infection/AIDS Asthma Severe infections, especially: Meningoencephalitis Septicaemia Epiglottis Infective endocarditis Coronary disease Myocardial infarction Unstable angina Arrthymias Imminent or potential suicide Intracerebral lesions, eg SAH Ectopic pregnancy

8. Classic pitfalls Abscess (hidden) Allergies Candida infection Chronic fatigue syndrome Domestic abuse including child abuse Drugs Herpes zoster Faecal impaction Foreign bodies Malnutrition (unsuspected) Menopause syndrome Migraine (atypical variants) Pregnancy (early) Seizure disorders Urinary infection

9. Seven primary masquerades Depression Diabetes mellitus Drugs Iatrogenic Self-abuse Alcohol Narcotics Nicotine Others Anemia Thyroid and other endocrine disorders Hyperthyroidism Hypothyroidism Spinal dysfunction Urinary infection

10. Is the patient trying to tell me something? Family conflict Sick or deceased friends/relatives Fear of malignancy STDS/HIV Impending “heart attack” Sexual problem

11. The exceptional potential in each primary care consultation [Stott & Davis] A ACUTE presenting problems B BEHAVIORAL modification of health seeking behaviours C CHRONIC continuing problems D DISEASE PREVENTION opportunistic health promotion

12. Puan Esah is a 53-year-old housewife who has come to see the doctor with runny nose and low grade fever for 2 days. She has been taking honey to soothe her throat. She is a known diabetic patient. A – acute – runny nose and fever B – behavioural – honey C – chronic – diabetes D – disease prevention – hypertension, menopause